TY - CONF A1 - Steger, Simon A1 - Stege, H A1 - Bretz, S. A1 - Hahn, Oliver T1 - A complementary spectroscopic approach for the non invasive in situ identification of synthetic organic pigments in modern reverse paintings on glass N2 - This work addresses the identification of synthetic organic pigments (SOP) in ten modern reverse paintings on glass (1912-1946) by means of an in-situ multi-analytical approach. The combination of the complimentary properties of mobile Raman spectroscopy and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) enabled the detection of sixteen SOP even in complex mixtures with inorganic compounds and binders. For the β-naphthol pigments, both Raman and DRIFTS yield appropriate results. DRIFTS was the preferred method for the detection of synthetic alizarin (PR83). Its diagnostic band pattern even allows its detection in complex mixtures with mineral pigments, binders and fillers. Raman spectroscopy yielded distinctive spectra for the triaryl carbonium pigments (PG1, PV2, PR81) and the two-yellow azo SOP (PY3, PY12), whereas DRIFT spectra were affected by extensive band overlapping. This may also occur in Raman spectra, but in less problematic amounts. Fluorescence is the major problem with Raman and it significantly hampers the SOP spectra even with the 785 nm laser. On the one hand the big spot size of DRIFTS (10 mm) limits the technique to rather large sampling areas, whereas the use of a 50× objective for in-situ Raman measurements permits a focus on small spots and aggregated SOP flakes. Moreover, “environmental” factors like temperature changes, artificial light, limited space and vibrations when people pass by need to be considered for in-situ measurements in museums. Finally, the results show the experimental use of SOP in modern reverse glass paintings. Among several rare SOP (e.g. PB52, PR81), two of them (PG1, PV2) have never been reported before in any artwork. T2 - Technart2019 CY - Bruges, Belgium DA - 07.05.2019 KW - Synthetic organic pigments KW - Reverse glass painting KW - DRIFTS KW - Raman spectroscopy PY - 2019 AN - OPUS4-48009 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Steger, Simon A1 - Oesterle, D. A1 - Mayer, R. A1 - Hahn, Oliver A1 - Bretz, S. A1 - Geiger, G. T1 - First insights into Chinese reverse glass paintings gained by non invasive spectroscopic analysis N2 - A non-invasive methodological approach (X-ray fluorescence (XRF), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), Raman spectroscopy) has been carried out to identify the pigments and classify the binding media in two Chinese reverse glass paintings (The Archer, Yingying and Hongniang) from the late 19th and early 20th centuries. The results reveal a combined use of traditional Chinese and imported European materials. Several pigments like cinnabar, lead white, orpiment, carbon black and copper-arsenic green (probably emerald green) were found in both paintings; red lead, artificial ultramarine blue, Prussian blue and ochre appear in at least one of the paintings. The presence of portlandite (Ca(OH)2) along calcite (CaCO3) in the fine-grained, white backing layer of Yingying and Hongniang indicates the presence of limewash. In Chinese tradition, limewash was produced from clamshells, and was then sold as clamshell white. In contrast to the Japanese pigment, Chinese clamshell white was made of finely grounded shells, which were heated over a low fire. The residue (CaO) forms portlandite (Ca(OH)2) when water is continuously added. This water-rich mixture is applied on the painting. Portlandite reacts with atmospheric CO2 during drying and forms fine-grained calcite (CaCO3) [1,2]. The identification of emerald green (The Archer) suggests an earliest manufacturing date in the 1830s [3] and promotes the sinological dating of the painting. Drying oil was classified as a binding media in most areas of both paintings. However, the orange background of The Archer yielded prominent bands of both proteinaceous and fatty binder. T2 - Technart2019 CY - Bruges, Belgium DA - 07.05.2019 KW - Reverse glass painting KW - Raman spectroscopy KW - Non-invasive analysis PY - 2019 AN - OPUS4-48010 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Torge, Manfred A1 - Seneschal-Merz, Karine A1 - Feldmann, Ines A1 - Bücker, Michael A1 - Oleszczuk, S. T1 - EDX-Analysis on medieval glasses and innovative protection of stained glass panels N2 - The church of Koszewko (Poland) is a brick building edified in the 15th century built on cobblestone foundations. There are five windows in the sanctuary. Three of them enclose heraldic panels from the Küssow’s family from the 15th century which are surrounded with Goethe glass from the 18th century to complete the windows. The colored heraldic panels are strongly damaged and corroded with massive paint layer losses, glass- and leadbreakages. Those medieval glass fragments have been shortly discovered and are of particular interest for Poland since only few medieval glazing have been conserved. The damages as well as the glass compositions have been investigated with ESEM/EDX. Two categories of medieval glass compositions have been identified. The blue glass is particularly sensible to corrosion because of his high content in K2O. The colorless and the red glass samples belong to a stable glass type. Due to the thickness of the gel layer, it is easy to see that the degradation is strongly proceeded. The protection of those medieval stained-glass panels is absolute necessary. The medieval panels have been restored and surrounded from a copper frame. Then they have been fixed on the wood frame in the church. The exterior glazing has been closed with a panel of Goethe glass. The gap between the Goethe- and the medieval glass is about 3 cm. The Goethe glass panel has been stabilized with a film based on polyester to protect the medieval glasses against any damages. In this way, a low cost protective glazing has been installed for a long-term conservation of each medieval stained-glass panels. The climate measurements over the period of one year on the restored windows are in process. The temperature and the relative humidity are recorded in the church interior, in the gap between the original and the Goethe glass and outdoors. T2 - 93rd Annual Meeting of DGG and Annual Meeting of USTV CY - Nuremberg, Germany DA - 13.05.2019 KW - Medieval glasses KW - Stained glasses KW - EDX Analysis KW - Corrosion PY - 2019 AN - OPUS4-48025 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Selina A1 - Schreiber, Frank T1 - Antimicrobial resistance in soil microbes mediated by resistance evolution and horizontal gene transfer (HGT) N2 - Questions: Biocides are in contact with soils through direct application and passive leaching from protected materials. Consequently, soil microorganisms are exposed to toxic biocides even though they are not their primary targets. Soil is a large reservoir of microbial diversity and has been hypothesized to be a crucial factor for the evolution and spread of antimicrobial resistance. Currently, there is little knowledge on how biocides used to protect materials affect the evolution and spread of resistance. Thus, our aim is to investigate the risk for the evolution of biocide resistance and cross-resistance to antibiotics. In addition, we aim to elucidate the affect of biocides on the spread of resistance via horizontal gene transfer (HGT). Methods: In laboratory evolution experiments we culture selected model soil microorganism with representative biocides followed by antibiotic cross-resistance determination and genome sequencing. Moreover, we investigate if the selected biocides affect the HGT frequency of plasmids that carry resistance genes among soil microorganism and the consequences for survival of the affected populations. Results: Our initial results show only small increases of biocide resistance during serial transfers in the presence of biocides. One reason for this might be the narrow selective window for biocide resistance due to steep dose-response relationships. Furthermore, we will present results from ongoing experiments on the effects of material preservatives on HGT frequencies facilitating microbial community adaptation to stress. Conclusions: The results will enable future risk assessment regarding resistance evolution for biocides used as material preservatives. T2 - 5th International Symposium on the Environmental Dimension of Antibiotic Resistance (EDAR) CY - Hong Kong, China DA - 09.06.2019 KW - Biocides KW - Horizontal gene transfer HGT KW - Microbiology KW - Resistance evolution KW - Antimicrobial resistance PY - 2019 AN - OPUS4-49401 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weimann, Karin A1 - Adam, Christian T1 - Gypsum plasterboard recycling - a sustainable approach N2 - Gypsum (calcium sulfate dihydrate) has excellent building material properties and has been widely used in constructions in the last decades in many countries. Accordingly, an increase of waste gypsum in C&D waste is expected in the upcoming years. On one hand, sulfates are unwanted in other secondary building materials (particularly in recycled concrete aggregates) and should be minimized for quality reasons. On the other hand, used gypsum from CDW can also be used in gypsum production if the high quality requirements for the recycled gypsum – especially regarding the sorting accuracy - are met. A large percentage of the gypsum from buildings was installed as gypsum plasterboards in interior fittings so far. Gypsum plasterboards are comparatively simple to remove and to separate during selective dismantling. Therefore, a high sorting purity can be achieved. In addition, techniques for the recycling of gypsum plasterboards already exist and high quality standards can be achieved. Also, the reuse in gypsum production has been improved in the last decade. Furthermore, an environmental evaluation of the whole process of gypsum plasterboard recycling and reuse showed that this approach can be environmentally advantageous. Therefore, a closed-loop recycling of gypsum plasterboards is feasible. This poster will show the development of gypsum consumption in different countries as well as a prognosis for the upcoming of gypsum in CDW in the future decades in Germany. Furthermore, a simplified scheme of the recycling process and selected results from an environmental evaluation will be presented. T2 - Conference on Mining the European Anthroposphere: Poster session CY - Bologna, Italy DA - 20.02.2020 KW - LCA KW - Gypsum recycling PY - 2020 AN - OPUS4-51435 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Raedel, Martina A1 - Bücker, Michael A1 - Feldmann, Ines A1 - Reimann, M. T1 - Conservation of damaged architectural aluminum elements N2 - Aluminum is an often-used building material in modern architecture. In recent years buildings from the 1950th and 1960th are increasingly subject of conservation works including the aluminum parts. Typical surface damages are signs of corrosion caused by weathering processes or scratches in the anodized layer due to extensive wear. To repair damaged aluminum surfaces, there are usually two options: smaller areas are repaired by using a touch-up pen, for larger damages it is necessary to remove the anodized layer completely. Both possibilities are disadvantageous for the objects; the touch-up pen often does not match the color together with an insufficient corrosion protection, while newly anodized layers often differ in color and gloss from the original surface. For this reason, a research project was initiated to develop a mobile method to repair anodized aluminum parts. The first step focusses on the mobile anodization process by using the electrolyte with a gel substrate. Different cathodic materials are to be tested together with appropriate cooling material. The anodized area should be isolated to protect undamaged areas. Examinations of the produced layers are conducted by using Keyence microscope, eddy current testing and ESEM analysis. Further steps are to transform the coloring and sealing process for mobile application. Color could be applied by using a brush or by spray while the sealing process could be performed with water vapor. An heatable putty knife could be used, if heating up the area will be necessary. Once the application process is developed, the anodization will be tested on samples with artificial damages, fixed in horizontal and vertical positions. The stability of the anodized surface will be examined by accelerated ageing in a climate chamber and outdoor weathering. The electrolyte (diluted sulfuric acid) was combined with a gel binder to enable a mobile application. Several thickening agents were tested concerning their conductivity and stability in acid systems. Anodization tests with different cathodic material and shapes were conducted. The temperature during anodization was controlled and adjusted if necessary. The anodized area was restricted by using either a lacquer, an adhesive or a removable silicon barrier. The fist results show the feasibility of the method on enclosed areas. The achieved thickness was measured by eddy current testing and the structure was controlled by ESEM analysis. The examinations show a connection between thickness and porosity of the anodized layers and the temperature during the application process. Next steps are testing mobile coloring and sealing methods followed by mobile anodization on artificial damaged areas. T2 - Metal 2019 CY - Neuchâtel, Switzerland DA - 02.09.2019 KW - Mobile anodisation KW - Aluminium KW - Conservation KW - Damage repair PY - 2020 UR - https://www.lulu.com/shop/claudia-chemello-and-laura-brambilla-and-edith-joseph/metal-2019-proceedings-of-the-interim-meeting-of-the-icom-cc-metals-working-group-september-2-6-2019-neuch%C3%A2tel-switzerland-ebook/ebook/product-24517161.html AN - OPUS4-51479 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schraut, Katharina A1 - Adamczyk, Burkart A1 - Simon, Sebastian A1 - von Werder, Julia A1 - Meng, Birgit A1 - Stephan, D. A1 - Adam, Christian T1 - Formation of tricalciumsilicate from post-treated metallurgical slags N2 - LD-slags differ from Ordinary Portland Cement (OPC) mainly in a higher content of iron oxides and a low content of Tricalciumsilicate (Alite). In the context of an improved resource usage, a procedure to convert LDslags into cement clinker was investigated. T2 - 15th International Congress on the Chemistry of Cement CY - Prague, Czech Republic DA - 16.09.2019 KW - Tricalcium-silicate KW - Portland Cement KW - Alite KW - Steelmaking slag PY - 2019 AN - OPUS4-49591 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gorbushina, Anna A1 - Knabe, Nicole A1 - Voigt, Oliver A1 - Heeger, Felix A1 - Schumacher, Julia T1 - A Genetic Toolbox for Exploring the Life Style of the Rock-inhabiting Black Fungus Knufia petricola N2 - After their discovery on rock surfaces in cold and hot deserts, a polyphyletic group of ascomycetous black fungi was found to dominate a range of hostile environments – natural and man-made, from salterns to dishwashers, roofs and solar panels. Together with bacteria and algae they may establish sub-aerial biofilms and cause weathering of the surfaces they grow on. Their impressive survival abilities as well as their constitutive protective pigmentation and cluster-like microcolony organisation are similar in environmental isolates as well as in heat-tolerant opportunistic pathogens of animals and humans. The exact genetic properties that ensure their survival in extreme environments can be studied if some black fungi were amenable to genetic manipulations. We selected the rock-inhabiting fungus Knufia petricola (class Eurotiomycetes, order Chaetothyriales) that grows moderately in axenic culture and exhibits all the characteristics of black yeasts such as yeast-like cell growth, absence of reproductive structures and constitutive dihydroxynaphthalene (DHN) melanogenesis. For this environmental strain we developed protocols to efficiently generate and transform protoplasts resulting in stable homokaryotic transformants by targeting genes involved in pigment synthesis and expressing fluorescent reporter genes. Hence, endogenous and foreign genes can be expressed from episomal AMA1-containing plasmids and genome-integrated DNA constructs. Moderate rates of homologous recombination allow for both ectopic and targeted integrations. CRISPR-Cas9 was further validated as a strategy for obtaining selection marker-free mutants and silencing via RNA interference as an approach to study essential genes. Availability of this genetic toolbox and an annotated genome sequence is paving the way for studying interactions of K. petricola and other black yeasts with environmental stressors, material surfaces, soil matrices and phototrophic symbionts. T2 - VAAM symposium 'Molecular Biology of Fungi' CY - Göttingen, Germany DA - 19.09.2019 KW - Knufia petricola KW - Rock-inhabiting fungus KW - Genetics KW - Crispr-Cas9 PY - 2019 AN - OPUS4-49634 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abdallah, Khaled A1 - Knabe, Nicole A1 - Breitenbach, Romy A1 - Dementyeva, Polina A1 - Voigt, Oliver A1 - Gerrits, Ruben A1 - Schumacher, Julia A1 - Gorbushina, Anna T1 - Developing a genetic toolbox for Knufia petricola A95: a model for stress-tolerant and symbiose-competent rock-inhabiting fungi N2 - Black microcolonial fungi (MCF) are persistent inhabitants of rock surfaces in hostile desert environments. In these niches, MCF have evolved mineral-weathering and symbiotic capabilities as well as mechanisms to cope with multiple stresses such as solar irradiation, temperature extremes and low water activity. Due to their stress tolerance these ascomycetes are prominent in modern terrestrial ecosystems – like man-made material surfaces from roof to solar panels. MCF interactive capabilities support their facultative symbiotic relationships with cyanobacteria and ensure their rock-weathering geochemical activity. Using the rock-inhabiting fungus K. petricola A95 (Chaetothyriales), we developed transformation protocols and deleted genes responsible for production of the protective pigments melanins and carotenoids. To confirm that the mutant phenotypes were not due to hidden mutations, melanin synthesis was restored by complementing the mutants with the respective wild type genes. Strains of K. petricola carrying gene variants for fluorescent proteins EGFP and DsRed are available. We successfully labelled the cytoplasm, nuclei, peroxisomes and mitochondria. Targeted and ectopic integrations result in stable transformants suitable for further phenotypical characterization. As K. petricola is a non-pathogenic fungus with all characteristic features of MCF, including meristematic growth, melanized cell-walls, extracellular polymeric substances and extensive pigment production, our results will shed light on protective role of pigments during cell wall maturation and oxidative stress defence in rock-inhabiting MCF. Genes involved in environmental sensing or substrate and phototroph interactions are currently targeted. With the help of a mutant collection and fluorescently labelled K. petricola we will be able to investigate interactions of MCF with environmental stressors, mineral substrates, soil matrices and phototrophic symbionts. T2 - Fungal Genetics Conference 2019 CY - Asilomar, CA, USA DA - 12.03.2019 KW - Knufia petricola KW - Genetics KW - Melanin PY - 2019 AN - OPUS4-49635 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schumacher, Julia A1 - Heeger, Felix A1 - Whitfield, Daniel A1 - Knabe, Nicole A1 - Nai, Corrado A1 - Schumacher, Julia A1 - Broughton, William A1 - Cuomo, C. A1 - de Souza, E. A1 - Lespinet, O. A1 - Mazzoni, C. A1 - Monaghan, M. A1 - Gorbushina, Anna T1 - Exploring the genome of the black yeast Knufia petricola N2 - Black yeasts form a polyphyletic group of Ascomycota that colonize bare surfaces like rocks, facades of buildings, and solar panels. Their protective adaptations enable an adequate response to fluctuating and diverse temperature, water and UV radiation stresses. Together with bacteria and algae they form sub-aerial biofilms (SAB) this way discoloring and weathering the surfaces they grow on. Strain A95 of Knufia petricola (Eurotiomycetes, Chaetothyriales) displays both typical yeast-like cell growth and constitutive dihydroxynaphthalene (DHN) melanogenesis. Along with the cyanobacterium Nostoc punctiforme as photobiont, it is already used in a model system for studying SAB formation and bio-weathering. Applying the recently developed tools for the generation of deletion mutants will allow to define gene functions and to identify genes critical for abiotic and biotic interactions. We present a chromosome-level genome assembly and annotation for K. petricola A95. The genome was assembled with MaSuRCA using a hybrid assembly approach of Illumina MiSeq and PacBio SMRT sequencing data. The resulting assembly consists of 17 contigs including the complete mitochondrial genome and five complete chromosomes. It shows indication of repeat-induced point mutations (RIP). Supported by RNA sequencing data from eight different growth conditions, 10,994 genes were predicted with the BRAKER2 pipeline. Functional annotation of genes was obtained from general functional annotation databases and the fungal specific database FungiPath. Comparative analyses are in progress to identify genes specific to black yeasts, that may facilitate the survival on exposed surfaces. In sum, the genome sequence of K. petricola is a valuable resource to gain insight into the protein inventory and functional pathways of extremotolerant and symbiosis-capable fungi. T2 - Fungal Genetics Conference 2019 CY - Asilomar, CA, USA DA - 12.03.2019 KW - Knufia petricola KW - Black fungus KW - Genome sequence PY - 2019 AN - OPUS4-49636 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Even, Morgane A1 - Juritsch, Elevtheria A1 - Jann, Oliver A1 - Richter, Matthias T1 - Towards an efficient procedure for the analysis of VVOC emissions N2 - This poster summarizes the points that need to be addressed towards the standardization of an efficient procedure for the analysis of VVOC emissions: Standard mixture generation and investigations on mutual reactivity, selection of an appropriate sorbent combination, water management and choice of a suited GC column. T2 - Indoor Air 2020: The 16th conference of the international society of indoor air quality and climate CY - Online meeting DA - 01.11.2020 KW - VVOCs KW - Analytical method KW - ISO 16000-6 KW - EN 16516 PY - 2020 AN - OPUS4-52023 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dinter, Adelina-Elisa A1 - Wurzler, Nina A1 - von der Au, Marcus A1 - Özcan Sandikcioglu, Özlem A1 - Koerdt, Andrea A1 - Meermann, Björn T1 - Examination of biological samples by means of single-cell ICP-ToF-MS N2 - Up to now, different analytical methods for single cell analysis exist focusing on key features such as size, shape, morphology and elemental composition. The combination of the latest ICP-MS techniques - ICP-ToF-MS - together with the latest developments in the field of sample delivery - micro droplet generator (MDG) – will allow a Deep insight into the composition and size of cells. Microbiologically influenced corrosion (MIC) is an oxidation of metals affected by the presence or activity (or both) of microorganisms e.g. Shewanella Putrefaciens in biofilms on the surface of the corroding material. As this can happen for example in the soil on iron pipes of water pipes, in oil tanks or on steel sheet piling, there is great interest in MIC research, not only from various industrial sectors, but also from the environmental aspect. T2 - SALSA - Make & Measure CY - Online Meeting DA - 15.10.2020 KW - SC-ICP-ToF-MS KW - Single cell analysis KW - MDG ICP-ToF-MS KW - Microdroplet generator PY - 2020 AN - OPUS4-52441 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilke, Olaf A1 - Jann, Oliver T1 - Comparison of Formaldehyde Concentrations in Emission Test Chambers Using EN 717-1 and EN 16516 N2 - For many years EN 717-1 (Wood-based panels - Determination of formaldehyde release - Part 1: Formaldehyde emission by the chamber method) is the standard for formaldehyde emission testing of wooden boards. In 2017 EN 16516 (Construction products - Assessment of release of dangerous substances - Determination of emissions into indoor air) was published as a new harmonised standard for the emission testing of construction products. Because test chamber conditions are different, both standards give different concentrations for formaldehyde. For the determination of a conversion factor four test series were set up with different wooden boards. T2 - Conference on Indoor Air CY - Philadelphia, PA, USA DA - 22.07.2018 KW - Loading factor KW - Construction products KW - European standard KW - Air exchange rate PY - 2018 AN - OPUS4-45631 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Stroj, S. A1 - Schwibbert, Karin A1 - Kasemann, S. A1 - Domke, M. T1 - Laser-generated high wetting contrast surfaces for microbiological applications N2 - We demonstrate a 2D platform based on high contrast wetting patterns suitable for miniaturized microbiological assays. In principal, superhydrophilic spots are surrounded by a superhydrophobic surface area. The special structure of the superhydrophilic functional surface ensures that liquids, e.g. bacterial suspensions or biocide solutions, spread immediately and evenly on this surface without passing the wetting boundary. This feature allows a homogenous distribution of bacteria or chemical substances on well defined lateral dimensions. The superhydrophilic spots may also serve as substrate for bacterial biofilms. Due to the high wetting contrast and the fabrication process, it is possible to minimize the test areas as well as their distance to each other. We demonstrate the fabrication process of the high wetting contrast platform and also present a microbiological assay as an application example. Advantages of this platform are the use of low volumes and its potential of automated analysis. T2 - Biointerfaces International Conference CY - Zürich, Austria DA - 14.08.2018 KW - Biofilm KW - Bacterial growth KW - Laser structuring KW - Superhydrophobic surface KW - Superhydrophilic surface PY - 2018 AN - OPUS4-45863 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kjaervik, Marit A1 - Dietrich, P. A1 - Thissen, A. A1 - Schwibbert, Karin A1 - Defedov, A. A1 - Wöll, C. A1 - Unger, Wolfgang T1 - Exploring the capabilities of NAP-XPS: Application to metal-organic frameworks, nanoparticles and biofilms N2 - Near-ambient pressure XPS makes it possible to characterise samples not compatible to ultra-high vacuum, and enables the study of liquid-solid, gas-liquid and gas-solid interfaces. NAP-XPS meas-urements of biofilms, suspended nanoparticles and metal-organic frameworks were performed with EnviroESCA developed by SPECS. An interesting application is surface characterisation of biofilms, which are bacterial communities embedded in a self-produced polysaccharide matrix. Various model systems ranging from pure polysaccharides of alginate to biofilms harvested directly from the growth medium have been char-acterised in humid conditions[1]. NAP-XPS also makes it possible to characterise nanoparticles in solution. Silver nanoparticles in aqueous solution were characterised and the Ag 3d-spectrum compared to spectra obtained of dried nanoparticles in UHV-conditions[2]. The binding energy of the Ag 3d-core level peak was shifted by 0,6 eV towards higher binding energy for suspended nanoparticles compared to the dried sample measured in UHV. This can be assigned to a change in surface potential at the water-nanoparticle interface. Metal-organic frameworks (MOFs) are suitable materials for gas storage of small molecules due to their nanoporous, crystalline structure. However, instability in humidity remains an issue for many types of MOFs. XPS-measurements of the MOF-structure HKUST-1 were performed in various NAP-conditions to assess the stability of the sample and its interaction with the gas molecules as water, methanol and pyridine. T2 - 5th AP-XPS Workshop CY - Berlin, Germany DA - 11.12.18 KW - Biofilms KW - E. coli KW - NAP-XPS KW - Metal organic frameworks KW - Nanoparticles PY - 2018 AN - OPUS4-47060 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koerdt, Andrea A1 - An, Biwen Annie A1 - Özcan Sandikcioglu, Özlem A1 - Hermann, Annett A1 - Kunte, Hans-Jörg T1 - Investigation of methanogen-induced microbiologically influenced corrosion under dynamic environments N2 - Microbially influenced corrosion (MIC) of iron is usually attributed to sulfate-reducing microorganisms (SRM) which act upon the metal by the reactiveness of hydrogen sulfide, and by withdrawal of the available electrons in electrical contact with the metal. Methanogenic archaea can also cause MIC by directly withdrawing electrons from the iron surface for methanogenesis. However, the mechanistic details and kinetics of the overall process are poorly understood. Precipitation of siderite, a by-product of methanogenesis, (4Fe + 5HCO3 + 5H+  4FeCO3 + CH4 + 3H2O) can lead to an insulating layer on the metal surface and lower the corrosion rate. Still, the extent of FeCO3 precipitation may be significantly influenced by environmental conditions such as pH and advective processes. T2 - IGD-TP Exchange Forum 8 CY - Berlin, Germany DA - 04.12.2048 KW - Archaea KW - Biocorrosion KW - MIC KW - Environmental Simulation PY - 2018 AN - OPUS4-47136 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kleinbub, Sherin A1 - An, Biwen Annie A1 - Özcan Sandikcioglu, Özlem A1 - Dommisch, H. A1 - Koerdt, Andrea T1 - The impact of methanogenic Archaea on material, environment and health N2 - Microbiologically influence corrosion (MIC) has become a big concern due the increased usage of different metals by our society. Microorganisms can use metal as an electron donor, causing unpredictable but serious damages. Nowadays it is known that besides sulfate reducing bacteria (SRB), other microorganisms including acetogens, iron oxidizers and methanogens can also induce MIC. Current studies related to methanogen-induced MIC (MI-MIC) mainly focused on environmental isolates from the oil and gas industry (e.g. Methanococcus maripaludis) with industrial materials e.g. iron. However, MI-MIC can occur in many other environments as well, including the oral cavity. Methanobrevibacter oralis is a methanogen isolated from the human oral cavity and was found more frequently in patients suffering from peri-implantitis/periodontitis. Titanium-implants removed from those patients have also showed clear signs of corrosion. The aim of our study is to establish and analyze corrosion potentials of dental metals (e.g. titanium) by oral methanogens. Periodontal pockets samples from patients suffering from periodontitis/peri-implantitis were taken for methanogenic and SRB enrichments. Stainless steel, pure titanium or Ti-6Al-4V alloy was used for corrosion studies. Corrosion rates and methane production were measured using weight-loss method and gas chromatography, respectively. Metal surfaces were visualized with scanning electron microscopy. Microbial communities in the dental pockets of healthy people and patients will be compared using 16S rRNA amplicon sequencing. Overall, this is the first study investigating the susceptibility of different dental implant materials to corrosion using human-related Archaea. The outcomes of this study can be further explored for a variety of clinical applications. T2 - ISME 17th International Symposium on Microbial Ecology CY - Leipzig, Germany DA - 12.08.2018 KW - Methanogens KW - Corrosion KW - Biofilm PY - 2018 AN - OPUS4-45932 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vogel, Christian A1 - Sekine, R. A1 - Steckenmesser, D. A1 - Lombi, E. A1 - Herzel, Hannes A1 - Zuin, L. A1 - Wang, D. A1 - Félix, R. A1 - Adam, Christian T1 - Combining diffusive gradients in thin films (DGT) and spectroscopic techniques for the determination of phosphorus species in soils N2 - A wide range of methods are used to estimate the plant-availability of soil phosphorus (P). Published research has shown that the diffusive gradients in thin films (DGT) technique has a superior correlation to plant-available P in soils compared to standard chemical extraction tests. In order to identify the plant-available soil P species, we combined DGT with infrared and P K- and L-edge X-ray adsorption near-edge structure (XANES) spectroscopy. This was achieved by spectroscopically investigating the dried binding layer of DGT devices after soil deployment. All three spectroscopic methods were able to distinguish between different kinds of phosphates (poly-, trimeta-, pyro- and orthophosphate) on the DGT binding layer. However, infrared spectroscopy was most sensitive to distinguish between different types of adsorbed inorganic and organic phosphates. Additionally, also intermediates of the time-resolved hydrolysis of trimetaphosphate in soil could be analyzed. Furthermore, infrared and XANES microspectroscopy make it also possible to analyze P compounds on the binding layer with a lateral resolution down to 1 µm2. Therefore, P species of a spatial soil segment (e.g. rhizosphere) can be mapped and analyzed. T2 - Phosphorus in Soil and Plants (PSP6) CY - Leuven, Belgium DA - 10.09.2018 KW - Soil P species KW - Spectroscopy KW - DGT PY - 2018 AN - OPUS4-45961 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Torge, Manfred A1 - Feldmann, Ines A1 - Seneschal-Merz, Karine A1 - Bücker, Michael A1 - Oleszczuk, O. T1 - EDX-Untersuchungen an mittelaltelichen Gläsern und innovativer Schutz der Glasmalereien N2 - In Vorbereitung einer Restaurierung erfolgten naturwissenschaftliche Untersuchungen zu Schadensphänomenen und Glaszusammensetzungen an mittelalterlichen Gläsern aus der Dorfkirche in Koszewko (Polen)im Environmental Scanning Electron Microscope (ESEM) mit EDX. Die Ergebnisse zeigen, dass die Glasverwitterung schon sehr stark vorangeschritten ist und ein zukünftiger Schutz der mittelalterlichen Glasmalereifelder vor Umwelteinflüssen unbedingt notwendig ist. Es wurde ein Schutzverglasungsystem entwickelt, das speziell auf den langfristigen Erhalt der einzelnen mittelalterlichen Glasmalereifelder ausgelegt ist. T2 - 21th Congress of Association Internationale pour l´Histoire du Verre CY - Istanbul, Turkey DA - 03.09.2018 KW - Glasanalyse KW - ESEM KW - Schutzverglasung PY - 2018 AN - OPUS4-45947 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pietsch, Franziska A1 - Schreiber, Frank T1 - Selection of resistance in bacterial biofilms grown on antimicrobial surfaces in a multidrug environment N2 - Background Bacterial biofilms are regarded as the most common cause of chronic infections and are often associated with medical devices, such as implants and catheters. Bacteria growing in biofilms produce a protective, extracellular matrix, which enables them to tolerate much higher antimicrobial concentrations than free-living bacteria and survive long enough to acquire antimicrobial resistance. Preventive and therapeutic strategies against biofilm infections in clinical settings commonly involve the application of multiple antimicrobials: biocidal coatings on the biomaterials and systemically administered antibiotics. This frequent practice harbors the risk of the development of cross-resistance via shared resistance mechanisms between antimicrobials used in material coatings and administered antibiotics. Aim Our goal is to determine how bacteria adapt to antimicrobials during biofilm formation on surfaces coated with antimicrobials and how population dynamics within biofilms affect the transmission of resistance mutations. Specifically, we want to identify antimicrobial-antibiotic-combinations that select for and against antibiotic resistance in biofilms by following the population dynamics of resistant and susceptible strains in competition assays on a single cell level. Methodology To study the effect of antimicrobial-antibiotic exposure on resistance development and population dynamics on bacterial biofilms in a multidrug environment, we will grow Pseudomonas aeruginosa on glass surfaces with and without antimicrobial coatings and expose them to antibiotics. First, we will screen in vitro for combinations of antibiotics and antimicrobials that select for and against antibiotic resistance. Second, effective combinations will be chosen for in-depth investigations during bacterial adhesion and of mature biofilms of resistant and susceptible genotypes. Third, based on the outcome of the screen and the obtained mechanistic understanding we will choose a clinical example in which we study the relevance of our findings in biofilms grown in vivo. Relevance Studying the biointerfacial interactions between bacterial biofilms and medical devices in terms of population dynamics as well as on single cell level during multidrug selection will help us understand how drug resistance develops and spreads in persistent biofilm infections. Based on our findings we aim to provide clinical recommendations for improved administration of antibiotics/antimicrobials in combination with medical device materials in order to mitigate against biofilm associated antimicrobial resistance. T2 - Biofilms 8 Conference CY - Aarhus, Denmark DA - 27.05.2018 KW - Resistance KW - Antimicrobials PY - 2018 AN - OPUS4-46524 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hoffmann, Marie A1 - Adam, Christian T1 - Scandium and scandium-aluminium alloy production from European metallurgical by-products N2 - The SCALE Project is a Horizon2020 Project (GA°730105) that aims to develope a secure supply chain for Scandium in Europe. To achieve that, the whole value chain is investigated and new methodologies and techniques are being developed. In BAM we are characterizing potential Scandium-bearing industrial by-products. T2 - Poster presentation during Exploration Geology Short Course DMG CY - Freiburg, Germany DA - 19.02.2018 KW - Scandium KW - Red Mud KW - Aluminium KW - SCALE PY - 2018 AN - OPUS4-46539 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hoffmann, Marie A1 - Adam, Christian T1 - Scandium in industriellen Reststoffen - Die Suche nach der Nadel im Heuhaufen N2 - Im Zusammenhang mit dem Horizon2020 geförderten Projekt SCALE (GA°730105) untersuchen wir an der BAM die Scandium Spezies in industriellen Restsoffen wie zum Beispiel Rotschlamm. Dabei kommen Methoden wie Elektronenmikroskopie, LA-ICP-MS und auch X-ray Adsorption near edge structure an Synchrotron-Lichtquellen zum Einsatz. Das Verständnis der Bindungsformen des Scandiums soll im Weiteren helfen, metallurgische Gewinnungsmethoden zu verbessern und anzupassen. T2 - Posterpräsentation während des Themenfeldtags Umwelt CY - Berlin, Germany DA - 18.10.2018 KW - Scandium KW - Rotschlamm KW - Aluminium KW - SCALE PY - 2018 AN - OPUS4-46540 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - An, Biwen Annie A1 - Kleinbub, Sherin A1 - Schreiber, Frank A1 - Koerdt, Andrea T1 - Investigating the effects of biocides and corrosion inhibitors on corrosive methanogens N2 - Microbiologically influenced corrosion (MIC) is the deterioration of metals due to the metabolic activities of microorganisms. Microorganisms can take electrons directly from the metal surface (EMIC) thereby causing corrosion. Well known culprits of EMIC are: sulfate-reducing bacteria (SRB), acetogens and methanogens. Our aims - Develop a novel flow system to study MIC by methanogens to mimic industrial Environments - Investigate the inhibitory concentrations of biocides targeting SRB on corrosive methanogenic strains - Investigate the inhibitory effects of corrosion inhibitors on methanogens - Compare the inhibitory concentrations to SRB T2 - BAM meeting CY - BAM, Berlin, Germany DA - 06.06.2018 KW - MIC projekt KW - Mikrobiell beeinflusste Korrosion KW - Microbiologically influenced corrosion KW - Korrosion KW - Corrosion KW - Material degradation KW - Biocide PY - 2018 AN - OPUS4-46010 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cohen, Zina A1 - Bonnerot, Olivier A1 - Schlanger, J. A1 - Hahn, Oliver A1 - Rabin, Ira T1 - Composition analysis of writing materials in Geniza fragments N2 - The Cairo Geniza is an “archive” discovered in the 19th century in Ben Ezra Synagogue in Fustat, a district in Old Cairo (Egypt), located south of the center of modern Cairo. The giant collection of mostly Jewish documents that vary in genres, languages and writing supports contains a large number of early medieval Hebrew manuscripts, mostly in fragmentary form. The larger part of the Cairo Geniza is stored today in the Cambridge University Library (CUL). The Geniza provides sources for the literary, linguistic, historical studies of the various aspects Jewish life. As the documents attest, at least two Jewish communities co-existed in Fustat up to 11th century: a so-called Babylonian and Palestinian. These communities had different leaders, different traditions and lived independently. The differences seem to manifest themselves also in the paleographical, codicological and some material properties of the manuscripts produced by each community. The aim of this project is to compare the inks used in the Jewish documents depending on different variables: support (paper, parchment), purpose of the manuscript (legal, private, religious), provenance of the scribe. For the determination of the inks type and composition we had to choose non-invasive, non-destructive and portable techniques to analyse the corpus directly in the CUL. The analyses were carried out with a mobile energy dispersive micro-X-ray spectrometer ArtTAX® (Bruker GmbH, Berlin, Germany), which consists of an air-cooled, low-power molybdenum tube, polycapillary X-ray optics (measuring spot size 70 µm in diameter), an electrothermally cooled Xflash detector, and a CCD camera for sample positioning (Bronk et al 2001, Hahn et al. 2010). All measurements are executed using a 30 W low-power Mo tube, 50 kV, 600 µA Mo tube, and with an acquisition time of 15 s (live time) to minimize the risk of damage (Fig. 1, 2). Fig. 1: XRF spectrometer probe above a manuscript fragment Fig. 2: Typical element profile of a XRF linescan The Dino Lite digital stereomicroscope (Fig. 3) features built-in LED illumination at 395 nm and 940 nm and a customized external white light source. During use, the microscope is fastened to a small tripod or mounted on a Plexiglas ring holder that incorporates a white light source. Fig. 3: Dino Lite digital stereomicroscope Fig. 4: Details of one fragment (T-S 16.124) observed with the Dino microscope (x20). On the left, when illuminated with NIR (Near-Infrared, 940 nm) light, the ink fades, indicating iron-gall ink. On the right, the image under NIR light does not change. It is carbon ink. On example of these studies is the manuscript T-S 16.124 (Cambridge University Library, Fig. 5) whom belongs to the third corpus. It is a deed, written in Hebrew, dated from 1328 (= 1017 CE) and witnessed by a very high number of people (6) comparing to the standard of similar documents (between 2 and 3), from at least two different Jewish communities in Fustat (trans congregational). The verso is written in Arabic (Bareket 1999). Fig. 5: Manuscript T-S 16.124 (Cambridge University Library) To compare the inks, we used the fingerprint model. This method relies on the determination of characteristic elemental compositions and represents the amount of a minor constituent relative to the main component, iron in iron gall ink (Malzer et al. 2004, Hahn et al. 2004, Rabin et al 2014). However, a calculation of a fingerprint based on XRF measurements is not possible in the case of carbon ink since carbon, its main component, cannot be detected with this technique. Fig. 6: Ink fingerprint T-S 16-124 (recto) normalized to iron (Fe) Conclusion We show that using reflectography and XRF analysis it is possible to sort the inks according to their type. In the case of the iron-gall inks, use of the ink fingerprint, i.e. amount of the vitriol components normalized to iron we can make direct comparisons of the ink composition. We would like also to stress that though the methods of material analysis listed above have been successfully employed in the field of cultural heritage and conservation including ancient and medieval manuscripts they have not yet been used to study fragments from the Cairo Genizah. Therefore, we believe that this research project is a pioneering study that will provide new insights into the history of Hebrew writing materials, their production techniques and materials and, thus, contribute new data to the field of Hebrew paleography. T2 - Konferenz DESY “Archäometrie und Denkmalpflege 2018” CY - Hamburg, Germany DA - 20.03.2018 KW - Ink KW - XRF Analysis KW - Manuscript PY - 2018 AN - OPUS4-46042 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vandrich, Jasmina A1 - Alfaro Espinoza, Gabriela A1 - Kunte, Hans-Jörg T1 - Tampering with ectoine production and excretion in Halomonas elongata using CRISPRi and gene knock-outs N2 - The halophilic bacterium Halomonas elongata can tolerate salt concentrations above 10% NaCl and uses the accumulation of the compatible solute ectoine as a major osmoregulatory mechanism. Ectoine can be accumalted inside the cell through import from the medium or de novo synthesis and establishes an osmotic equilibrium with the surrounding1. Ectoine also protects proteins from the effects of freezing, drying and high temperatures4 and DNA from ionizing radiation2. These features make ectoine a valuable compound for cosmetics and medical devices. H. elongata was originally isolated from a solar salt facility, where it thrives under high salt concentrations. It was found that marine prokaryotes, which are exposed to high oxidative stress in their environment, vary glycolytic strategies5. A variation in the use of the glucose metabolic pathways is also assumed for H. elongata. T2 - International Society for Microbial Ecology CY - Leipzig, Germany DA - 12.08.2018 KW - Halomonas CRISPR Ectoine PY - 2018 AN - OPUS4-46080 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vandrich, Jasmina A1 - Alfaro Espinoza, Gabriela A1 - Kunte, Hans-Jörg T1 - Establishing CRISPRi in Halomonas elongata to uncover metabolic pathways N2 - The halophilic bacterium Halomonas elongata can tolerate salt concentrations above 10% NaCl and uses the accumulation of the compatible solute ectoine as a major osmoregulatory mechanism. Ectoine can be accumalted inside the cell through import from the medium or de novo synthesis and establishes an osmotic equilibrium with the surrounding1. Ectoine also protects proteins from the effects of freezing, drying and high temperatures4 and DNA from ionizing radiation2. These features make ectoine a valuable compound for cosmetics and medical devices. H. elongata was originally isolated from a solar salt facility, where it thrives under high salt concentrations. It was found that marine prokaryotes, which are exposed to high oxidative stress in their environment, vary glycolytic strategies5. A variation in the use of the glucose metabolic pathways is also assumed for H. elongata. T2 - Association for General and Applied Microbiology CY - Wolfsburg, Germany DA - 15.04.2018 KW - Halomonas CRISPR Ectoine PY - 2018 AN - OPUS4-46081 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ghigo, Tea A1 - Steger, Simon A1 - Bonnerot, Olivier A1 - Hahn, Oliver A1 - Buzi, P. A1 - Rabin, Ira T1 - Understanding the technological evolution of writing materials. Scientific systematic study of inks from Coptic manuscripts N2 - While studying the socio-geographic history of inks, division 4.5 of the BAM (Bundesanstalt für Materialforschung und Prüfung) together with the Centre for the Study of Manuscript Cultures in Hamburg has developed a protocol for ink analysis. It consists of a primary screening to determine the type of the ink and a subsequent in-depth analysis using several spectroscopic techniques: XRF, FTIR, and Raman. In most cases, we can obtain satisfactory results using a non-invasive protocol. However, mixed inks that contain no metals evade such a protocol. These inks constitute a heterogeneous group of media used especially in the Middle East and the Islamicate world since at least the 10th century; they are characterized by blending carbon ink and tannins, with or without the addition of vitriol. Our own research aims primarily at recreating a socio-geographic history of inks, parchment, and papyrus and includes the comparative analysis of the writing materials of the Dead Sea Scrolls, ink and papyrus in Ancient and Hellenistic Egypt, and inks in documents from various contemporary medieval communities in Fustat (first nucleus of Cairo). During many years of study, we concluded that the continuous production of Coptic manuscripts from late Antiquity to the Middle Ages offers a unique opportunity for historical study of the ink in a large geographic area. Thanks to the collaboration with the ERC project “PAThs” (www.paths.uniroma1.it), based at the University of Rome La Sapienza, and within the activities of a PhD research dedicated to this topic, we therefore created a new branch of our project focused entirely on the analysis of Coptic inks, pigments, and dyes. This pioneering systematic study of writing materials coming from a specific area and time frame (5th-10th century) aims not only at a better understanding of the complex Coptic multicultural and plurilingual society, but also and mainly at clarifying the links among the Coptic and other societies between the ancient and medieval eras. Finally, it will cast light on the history of the technological development of inks in the eastern world, from Antiquity to the middle ages. T2 - Konferenz: Scientific Methods in Cultural Heritage Research, Gordon Research Conference CY - Castelldefels, Spain DA - 22.07.2018 KW - Coptic KW - Ink KW - Manuscript PY - 2018 AN - OPUS4-46024 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schwibbert, Karin A1 - Menzel, Friederike T1 - Bacterial Adhesion on Different Materials N2 - Biofilm formation on materials leads to high costs in industrial processes, as well as in medical applications. This fact has stimulated interest in the development of new materials with improved surfaces to reduce bacterial adhesion. We present a flow chamber system to test and quantify bacterial adhesion on materials that are part of antifouling concepts. The adhesion process is standardized and can be adapted to different bacteria in subaquatic of subaerial environments. It is combined with a standardized evaluation procedure based on statistical evidence. T2 - AMiCI Workshop Berlin CY - BAM Berlin, Germany DA - 07.06.2018 KW - Bacterial adhesion KW - Flow chamber system KW - Biofilm formation KW - Standardized test and quantification procedure PY - 2018 AN - OPUS4-46374 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koerdt, Andrea A1 - An, Biwen Annie A1 - Özcan Sandikcioglu, Özlem A1 - Widdel, F. T1 - Microbial corrosion of iron coupled to methanogenesis by strains from different environments N2 - Microbially influenced corrosion (MIC) of iron is usually attributed to sulfate-reducing microorganisms (SRM) which act upon the metal by the reactiveness of hydrogen sulfide, and by withdrawal of the available electrons in electrical contact with the metal. Methanogenic archaea are supposed to cause MIC. Because they do not produce hydrogen sulfide, withdrawal of electrons may be their main corrosive mechanism; however, mechanistic details and kinetics of the overall process are poorly understood. Precipitation of siderite (4Fe + 5HCO3 + 5H+  4FeCO3 + CH4 + 3H2O) can lead to an insulating layer on the metal surface and lower the corrosion rate. Still, the extent of FeCO3 precipitation may be significantly influenced by environmental conditions such as pH and advective processes. T2 - EMBO-Workshop CY - Vienna, Austria DA - 02.08.2018 KW - Methanogens KW - MIC KW - Corrosion KW - Environmental Simulation PY - 2018 AN - OPUS4-46396 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koerdt, Andrea A1 - An, Biwen Annie A1 - Özcan Sandikcioglu, Özlem A1 - Widdel, F. T1 - Microbial corrosion of iron coupled to methanogenesis by strains from different environments N2 - Microbially influenced corrosion (MIC) of iron is usually attributed to sulfate-reducing microorganisms (SRM) which act upon the metal by the reactiveness of hydrogen sulfide, and by withdrawal of the available electrons in electrical contact with the metal. Methanogenic archaea are supposed to cause MIC. Because they do not produce hydrogen sulfide, withdrawal of electrons may be their main corrosive mechanism; however, mechanistic details and kinetics of the overall process are poorly understood. Precipitation of siderite (4Fe + 5HCO3 + 5H+  4FeCO3 + CH4 + 3H2O) can lead to an insulating layer on the metal surface and lower the corrosion rate. Still, the extent of FeCO3 precipitation may be significantly influenced by environmental conditions such as pH and advective processes. T2 - ISME CY - Leipzig, Germany DA - 12.08.2018 KW - Methanogens KW - MIC KW - Corrosion KW - Environmental Simulation PY - 2018 AN - OPUS4-46397 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pietsch, Franziska A1 - Schreiber, Frank T1 - Selection of Resistance in Bacterial Biofilms Grown on Antimicrobial Surfaces in a Multidrug Environment N2 - Background Bacterial biofilms are regarded as the most common cause of chronic infections and are often associated with medical devices, such as implants and catheters. Bacteria growing in biofilms produce a protective, extracellular matrix, which enables them to tolerate much higher antimicrobial concentrations than free-living bacteria and survive long enough to acquire antimicrobial resistance. Preventive and therapeutic strategies against biofilm infections in clinical settings commonly involve the application of multiple antimicrobials: biocidal coatings on the biomaterials and systemically administered antibiotics. This frequent practice harbors the risk of the development of cross-resistance via shared resistance mechanisms between antimicrobials used in material coatings and administered antibiotics. Aim Our goal is to determine how bacteria adapt to antimicrobials during biofilm formation on surfaces coated with antimicrobials, how antimicrobial resistance mutations are acquired and evolve within mature biofilms, and how population dynamics within biofilms affect the transmission of resistance mutations. Specifically, we want to identify antimicrobial-antibiotic-combinations that select for and against antibiotic resistance in biofilms by following the population dynamics of resistant and susceptible strains in competition assays. Methodology We will grow biofilms of Pseudomonas aeruginosa on glass surfaces with and without antimicrobial coatings and expose them to antibiotics. Then we will track their physiological properties, evolutionary adaptations, and population dynamics. First, we will screen in vitro for combinations of antibiotics and antimicrobials that select for and against antibiotic resistance. Second, effective combinations will be chosen for in-depth investigations during bacterial adhesion and of mature biofilms of resistant and susceptible genotypes. Third, based on the outcome of the screen and the obtained mechanistic understanding we will choose a clinical example in which we study the relevance of our findings in biofilms grown in vivo. Relevance Studying the biointerfacial interactions between bacterial biofilms and medical devices in terms of population dynamics as well as on single cell level during multidrug selection will help us understand how drug resistance develops and spreads in persistent biofilm infections. Based on our findings we aim to provide clinical recommendations for improved administration of antibiotics/antimicrobials in combination with medical device materials in order to mitigate against biofilm associated antimicrobial resistance. T2 - Challenges and New Concepts in Antibiotic Research CY - Paris, France DA - 19.03.2018 KW - Resistance KW - Antimicrobials PY - 2018 AN - OPUS4-46398 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kjaervik, Marit A1 - Dietrich, P. A1 - Thissen, A. A1 - Schwibbert, Karin A1 - Unger, Wolfgang T1 - Depth-dependent analysis of model biofilms by combining laboratory- and synchrotron-based X-ray photoelectron spectroscopy N2 - Synchrotron XPS in the soft-X-ray regime is suitable for the detection of light elements commonly found in biological samples. Various model systems of biofilms have been developed and characterised at synchrotron- and lab-based facilities. By obtaining the chemical composition at various information depths, the vertical distribution of iodine in an artificial biofilm have been determined. T2 - Tenth Joint BER II and BESSY II User Meeting CY - Berlin, Germany DA - 05.12.2018 KW - Biofilms KW - HAXPES KW - XPS KW - Iodine KW - Synchrotron-XPS PY - 2018 AN - OPUS4-46929 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Selina A1 - Schreiber, Frank T1 - Priming in soil microbial communities mediated by biocide-induced horizontal gene-transfer N2 - Soil microbes are exposed to different environmental stressors originating from various sources. Biocides used as material preservatives can represent environmental stressors since they are in direct contact with the environment including soil. Microorganism in soils can adapt to stress by different mechanisms; for example, by transferring mobile genetic elements via horizontal gene transfer (HGT). Here, we hypothesize that material preservatives can cause increased frequencies of HGT (i.e. altered community permissiveness) facilitating microbial community adaptation to stress. Furthermore, we hypothesize that soil microbial communities are primed by biocide exposure facilitating the response to different types of stresses. We will incubate soil mesocosms with selected biocides to investigate if these compounds promote HGT of plasmids that carry resistance genes in soil microbial communities. Subsequently, we will prime the soil microbial community with sub-inhibitory concentrations of biocides followed by exposure to toxic biocide concentrations or other types of common environmental stresses including metals, antibiotics, and salt. Using suitable control experiments, a shift in the functional response of the primed as compared to the non-primed community would indicate that biocides prime microbial communities via HGT. Together these results will elucidate the effect of biocides on HGT-mediated adaptation to environmental stressors in soil microbial communities. T2 - SFB973 Stress Symposium CY - Berlin, Germany DA - 09.04.2018 KW - Resistance evolution KW - Horizontal gene transfer HGT KW - Biocides KW - Microbiology PY - 2018 AN - OPUS4-46285 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Selina A1 - Schreiber, Frank T1 - Priming in soil microbial communities mediated by biocide-induced horizontal gene-transfer N2 - Soil microbes are exposed to different environmental stressors originating from various sources. Biocides used as material preservatives can represent environmental stressors since they are in direct contact with the environment including soil. Microorganism in soils can adapt to stress by different mechanisms; for example, by transferring mobile genetic elements via horizontal gene transfer (HGT). Here, we hypothesize that material preservatives can cause increased frequencies of HGT (i.e. altered community permissiveness) facilitating microbial community adaptation to stress. Furthermore, we hypothesize that soil microbial communities are primed by biocide exposure facilitating the response to different types of stresses. We will incubate soil mesocosms with selected biocides to investigate if these compounds promote HGT of plasmids that carry resistance genes in soil microbial communities. Subsequently, we will prime the soil microbial community with sub-inhibitory concentrations of biocides followed by exposure to toxic biocide concentrations or other types of common environmental stresses including metals, antibiotics, and salt. Using suitable control experiments, a shift in the functional response of the primed as compared to the non-primed community would indicate that biocides prime microbial communities via HGT. Together these results will elucidate the effect of biocides on HGT-mediated adaptation to environmental stressors in soil microbial communities. T2 - BAM PhD Day 2018 CY - Berlin, Germany DA - 31.05.2018 KW - Resistance evolution KW - Horizontal gene transfer HGT KW - Biocides KW - Microbiology PY - 2018 AN - OPUS4-46286 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Selina A1 - Schreiber, Frank T1 - Antimicrobial resistance in soil microbes mediated by resistance evolution and horizontal gene transfer (HGT) N2 - Soil microbes are exposed to different environmental stressors originating from various sources. Biocides used as material preservatives can represent environmental stressors since they are in direct contact with the environment including soil. Microorganism in soils can adapt to stress by different mechanisms; for example, by the evolution of resistance by de novo mutations or acquisition of resistance genes via horizontal gene transfer (HGT). Here, we hypothesize that material preservatives could enhance the evolution of biocide resistance enabling the potential for cross-resistance to antibiotics. Furthermore, we hypothesize that material preservatives can cause increased frequencies of HGT (i.e. altered community permissiveness) facilitating microbial community adaptation to stress. We will culture soil microorganism with increasing concentrations of selected biocides followed by antibiotic susceptibility determination. Moreover, we will incubate soil mesocosms with selected biocides to investigate if these compounds promote HGT of plasmids that carry resistance genes in soil microbial communities. Together these results will elucidate the potential for the evolution of biocide resistance and cross-resistance to antibiotics as well as the effect of biocides on adaptation to environmental stressors in soil microbial communities. T2 - 17th International Symposium on Microbial Ecology CY - Leipzig, Germany DA - 12.08.2018 KW - Resistance evolution KW - Horizontal gene transfer HGT KW - Biocides KW - Microbiology PY - 2018 AN - OPUS4-46288 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kuhlbusch, T. A1 - Schmidt, Alexandra A1 - Kämpf, K. A1 - Bresch, Harald A1 - Bachmann, V. A1 - Völker, D. A1 - Schwirn, K. T1 - Test guideline on particle size and size distribution of manufactured nanomaterials N2 - The particle size distribution is considered the most relevant information for nanoscale property identification and material characterization. The current OECD test guideline on particle size and size distribution (TG 110) is not applicable to ‘nano-sized’ objects. In this project we thus develop a new OECD test guideline for the measurement of the size and size distribution of particles and fibers with at least one dimension in the range of 1 - 1000 nm. A fiber is defined as an object having an aspect ratio of length/diameter l/d >3. The width and length of each fiber should be measured concurrently. In order to measure the particle size distributions, many techniques are available. 9 methods for particles and 2 methods for fibres have been tested in a prevalidation study and appropriate methods will be compared in an interlaboratory round robin test starting in February 2019. T2 - Expertenaustausch Nanocluster und Malta-Initiative CY - Vienna, Austria DA - 30.10.2018 KW - Nanopartikel KW - Testguideline KW - Nano KW - Nanomaterial KW - Nano particle PY - 2018 AN - OPUS4-46669 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kleinbub, Sherin A1 - An, Biwen Annie A1 - Heidrich, Gabriele A1 - Özcan Sandikcioglu, Özlem A1 - Schenderlein, Matthias A1 - Dommisch, H. A1 - Wagner, D. A1 - Koerdt, Andrea T1 - Investigation of the corrosion potential by oral microorganisms related to periodontitis and peri-implantitis N2 - Since the early 19th century microorganisms were studied on their capabilities of causing microbiologically influenced corrosion (MIC) of metals. The most studied ones are sulfate-reducing bacteria (SRB), but others can corrode metals as well, e.g. acid-producing bacteria or methanogenic archaea (MA). However, these studies were mostly focused on metals related to the petroleum industry but metals for other industries, e.g. dentistry, are also susceptible to corrosion. The inert Titanium (Ti) is often used as an implant material, but it is a base metal. The formation of a passivating oxide layer allows Ti to be corrosion resistant at normal conditions. Nonetheless, scanning electron microscope images on dental implants from patients with acute peri-implantitis showed clear signs of corrosion. Currently, the corrosion mechanism of dental implants is unknown, but many indications suggest that oral microorganisms, including MA (Methanobrevibacter oralis) and SRB (Desulfomicrobium orale), could be involved. To determine if MA or SRB can corrode Ti (pure Ti or Ti-6Al-4V alloy), corrosion rate, methane and sulfide concentrations were analyzed. Electrical potential measurements using in-house developed electrochemical cells indicated a potential change on Ti in the presence of a corrosive MA strain compared to an abiotic control. Microbial composition comparison will be analyzed using samples from dental pockets of 150 infected patients by considering the quality of the implant and 50 healthy people by means of amplicon sequencing. Enrichments and isolation of pure cultures from the dentals samples are also examined for their corrosion behavior. Overall, this is the first study investigating the susceptibility of dental implant material to corrosion using human related MA. T2 - Annual Conference of the Association for General and Applied Microbiology CY - Mainz, Germany DA - 17.03.2019 KW - Methanogens KW - Microbiologically Influrenced Corrosion (MIC) KW - Biofilm PY - 2019 AN - OPUS4-47600 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Even, Morgane A1 - Hutzler, C. A1 - Wilke, Olaf A1 - Vieth, B. A1 - Luch, A. T1 - Investigations on emission properties of VOCs from consumer products made of polymers N2 - There is a need for an assessment of the emission properties of volatile organic compounds (VOCs) from consumer products. A method comparison was carried out to evaluate adapted and cost-effective procedures for such items. Smaller and automated emission chambers de-picted similar kinetics compared to a 203 L standard chamber. Toy samples made of PVC (Polyvinyl chloride) emitted more VOCs compared to other tested polymeric products. The emissions from 2 selected samples were studied to allow an evaluation of the resulting room concentration and external exposure of a child. Obtained concentrations were not of concern. T2 - Conference on Indoor Air 2018 CY - Philadelphia, USA DA - 22.07.2018 KW - Emission chamber testing KW - Volatile organic compounds KW - Consumer articles PY - 2018 AN - OPUS4-45662 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Horn, Wolfgang A1 - Richter, Matthias A1 - Wilke, Olaf T1 - Quality Improvement of VOC chamber emission tests observed for 10 years with round robin tests N2 - In Europe, the Construction Products Regulation (CPR, 2011/305/EU) sets basic requirements (BR) on how construction works must be designed and built. BR 3 “hygiene, health and the environment” states low emissions of toxic gases, Volatile Organic Compounds (VOCVOCs), particles, etc. from building materials. Meanwhile, a worldwide network of professional Commercial and non-commercial laboratories performing emission tests for the evaluation of products for interior use has been established. Therefore, comparability of test results must be ensured. The participation in Round Robin Tests (RRTRRTs) is a means to prove a laboratory’s proficiency. Since 2006 BAM offers such proficiency test for emission chamber test every two years. Any commercially available product on the market can be used as reference material, provided it is thoroughly characterised. However, these materials often emit only a few and material specific VOCs and appropriate homogeneity is not given. Therefore, alternative materials should be found. BAM used different materials over the years. Currently, the best suited reference material is a cured lacquer surface which contained several VOCs added to the liquid lacquer system. The round robin tests 2014, 2016 and 2018 were conducted with such a system. Compounds like Styrene or n-Alkanes like Decane or Tridecane were tested in many of the proficiency test operated by BAM. Up to now the relative standard deviation of these compounds decrease continuously. Starting with values about 30 % in 2008 we reached values for the mentioned compounds 15 to 20 % now. But even for more polar compounds improved results were received. Over the years the results of a large group of laboratories detected many compounds with much higher accuracy than at the beginning. So, the comparability between results of different laboratories becomes much better. T2 - International Conference on Risk Assessment of Indoor Air Chemicals CY - Berlin, Germany DA - 16.09.2018 KW - Chamber test KW - Round robin test KW - VOC-emission PY - 2018 AN - OPUS4-47906 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilke, Olaf A1 - Seeger, Stefan A1 - Brödner, Doris A1 - Erdmann, Kerstin A1 - Rasch, Fabian T1 - Chemical characterization of ultra-fine particles released from laser printers N2 - 11 laser printers from 5 manufacturers were purchased in 2017 and tested for their UFP emissions. Size resolved sampling of the emitted particles was done with a 13 stage (30 nm to 10 µm) low pressure cascade impactor. The sampled particles were analysed for their chemical composition by thermal extraction (vaporization at 290°C) followed by GC-MS analysis. High boiling cyclic siloxanes (D10 to D16) were detected as constituents of UFP from laser printers. In comparison to measurements in 2008, aliphatic long-chain alkanes (C22 to C34) were detected additionally as chemical constituents of UFP from most of the tested printers and their amounts were higher than for cyclic siloxanes. Printers of one manufacturer showed very low UPF emissions compared to the other manufacturers. T2 - Indoor Air Conference 2022 CY - Kuopio, Finland DA - 12.06.2022 KW - UFP KW - Thermal extraction KW - Cascade impactor PY - 2022 AN - OPUS4-55107 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kittner, Maria A1 - Altmann, Korinna A1 - Hamann, Sven A1 - Weyer, Rüdiger A1 - Kalbe, Ute T1 - Assessment of Microplastic Emissions from Artificial Turf Sports Pitches N2 - Following the recommendation of the European Chemicals Agency, on 25 September 2023 the European Commission passed a comprehensive new regulation to reduce emissions of microplastics (MP) into the environment, which includes the sale and use of intentionally added MP.1,2 This also applies to the application of synthetic rubber granulate infill in artificial turf systems and will ultimately have an impact on recreational sports. In Germany, rubber granulate made of ethylene-propylene-diene-monomer rubber (EPDM) is currently predominantly used. So far, there is no sufficient database for estimating MP emissions from artificial turf pitches into the environment and thus their relevance as a source of MP pollution.3 This topic is controversially discussed due to the complexity of sampling and analytics. To close this research gap, this project has the goal to determine mass balances for the emissions of MP from artificial turf pitches to allow an estimation of the amount of MP released per artificial turf pitch and year. Within this study, MP emissions of three artificial turf scenarios at different time states (unaged, artificially aged and real-time aged) are compared: the past (old turf: fossil based, synthetic infill), present (most commonly installed in Europe: fossil based, EPDM infill), and the future (turf with recycled gras fibres, no synthetic infill). To simulate the outdoor weathering during the lifespan of an artificial turf of approx. 15 years, brand-new artificial turf and EPDM rubber granulate were accelerated aged by means of UV weathering and mechanical stress. Potential MP emissions into surface and groundwater are simulated by lysimeter and shake experiments. MP mass contents are subsequently determined by Thermal Extraction Desorption Gas Chromatography/Mass Spectrometry. Using special microfilter crucibles allows the estimation of the particle sizes of the emitted MP, which is a fundamental requirement for an assessment of potential health hazards for humans. T2 - SETAC 2024 CY - Seville, Spain DA - 05.05.2024 KW - Mikroplastik KW - TED-GC/MS KW - Lysimeter KW - PAK KW - Schwermetalle PY - 2024 AN - OPUS4-60014 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schulz, Anne-Christine A1 - Schreiber, Frank T1 - Assessing co-selection of biocide and antibiotic resistance in wastewater microbial communities N2 - Biocides are used for a wide range of purposes, including disinfectants or preservatives. Biocides play a major role in the prevention of microbial infections in healthcare and animal husbandry. The use of biocides often leads to the discharge of active biocidal substances into wastewater streams, causing the exposure of wastewater microbial communities to subinhibitory concentrations. In turn, it is known that wastewater treatment plants (WWTP) are hotspots for antibiotic resistant bacteria. Since similar mechanisms confer resistance to biocides and antibiotics, exposure to biocides can result in co-selection of antibiotic resistant bacteria in WWTP due to biocides. Here, we investigate the magnitude and the drivers of co-selection of antibiotic resistance in natural wastewater microbial communities upon biocide exposure. Microbial communities will be sampled at the WWTP Ruhleben in Berlin and characterized regarding their biocide and antibiotic resistance. Changes in the resistance level after exposure to different biocides will be determined by enumerating resistant and non-resistant E. coli and heterotrophic bacteria on selective plates with and without several biocides and antibiotics. Moreover, we are establishing a synthetic community comprising about 100 environmental E. coli isolates each with different antimicrobial resistance traits. Each isolate will be tagged with a unique DNA-barcode. All isolates will be pooled and exposed to different biocides at various concentrations. The barcode labeling enables us to determine the abundance of each isolate at the beginning and end of the experiment by transposon-tag sequencing. The project results will inform risk assessment of the effects of biocidal residues on antimicrobial resistance selection in WWTP. The project is part of the BIOCIDE consortium funded within the call on Aquatic pollutants by JPI-AMR, JPI-OCEANS and JPI-WATER. T2 - 6th International Symposium onn the Environmental Dimension of Antibiotic Resistance - EDAR 6 CY - Gothenburg, Sweden DA - 22.09.2022 KW - Antibiotic resisitance KW - Biocide KW - Wastewater KW - Risk assesment PY - 2022 AN - OPUS4-56796 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vogel, Christian A1 - Doolette, A. A1 - Huang, J. T1 - Combining DGT and 31P NMR spectroscopy to determine phosphorus species in soil N2 - The amount of plant-available phosphorus (P) in soil strongly influences the yield of plants in agriculture. Therefore, various simple chemical extraction methods have been developed to estimate the plant-available P pools in soil. More recently, several experiments with the DGT technique have shown that it has a much better correlation to plant-available P in soils than standard chemical extraction methods (e.g. calcium-acetate-lactate (CAL), Colwell, Olsen, water) when soils with different characteristics are considered. However, the DGT technique cannot give information on the plant-available P species in the soil. Therefore, we combined DGT with solution 31P nuclear magnetic resonance (NMR) spectroscopy. This was achieved by using a modified DGT device in which the diffusive layer had a larger pore size, the binding layer incorporated an adsorption material with a higher capacity, and the device had a larger exposure area. The spectroscopic investigation was undertaken after elution of the deployed DGT binding layer in a NaOH solution. Adsorption tests using solutions of known organic P compounds showed that a sufficient amount of these compounds could be adsorbed on the binding layer in order for them to be analyzed by solution 31P NMR spectroscopy. Furthermore, various intermediates of the hydrolysis of trimetaphosphate in soil could be also analyzed over time. T2 - DGT Konferenz CY - Paris, France DA - 11.10.2023 KW - Soil KW - Phosphorus KW - Plant-availability PY - 2023 AN - OPUS4-58574 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bonse, Jörn A1 - Meissner, Sven A1 - Wasmuth, Karsten A1 - Schwibbert, Karin T1 - Impact of laser-induced periodic surface structures on the bactericidal properties of copper and brass N2 - Surfaces of metallic copper and copper alloys effectively inactivate microorganisms and viruses. However, the exact inactivation mode is still under debate. Main factors are assumed to include direct contact with the metallic surface, influx of Cu(I)/Cu(II) ions and the generation of reactive oxygen species (ROS). Laser-induced periodic surface structures (LIPSS) are frequently reported to act antibacterial, mainly by prevention of bacterial adhesion due to a limited number of possible adhesion points or by increasing the overall surface of intrinsically antibacterial materials. In time-kill experiments with E. coli and S. aureus we analyzed the impact of LIPSS on the toxicity of metallic copper and brass. We also conducted ROS accumulation assays and conclude that the application of LIPSS is not generally straight forward to obtain or improve antibacterial surfaces. Thus, the antibacterial effects of LIPPS. T2 - 2023 Spring Meeting CY - Strasbourg, France DA - 29.05.2023 KW - LIPSS KW - Antimicrobial KW - Reactive oxygen species PY - 2023 AN - OPUS4-58465 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Herzel, Hannes A1 - Adam, Christian A1 - Emter, J. A1 - Leimkötter, D. A1 - Künstler, J. A1 - Schaaf, T. A1 - Kraus, F. T1 - Demonstrationskampagne und Klärschlammasche-Monitoring N2 - Im Verbundprojekt R-Rhenania wird eine industrielle Demonstrationsanlage am Standort der Monoverbrennungsanlage Altenstadt der Firma Emter errichtet und im Jahr 2024 den Betrieb aufnehmen. Die vorhandene Rostfeuerung-Monoverbrennung wird so umgebaut, dass ein neues thermochemisches Verfahren integriert werden kann, welches hochwirksame und schadstoffarme Dünger produziert (bis zu 17.000 t/a). Die thermochemischen Produkte werden in Gefäß- und Feldversuchen im ökologischen Landbau auf ihre Düngewirkung getestet. Die Umweltverträglichkeit der Demonstrationsanlage wird untersucht, wie auch die Übertragbarkeit des Verfahrens auf weitere Regionen. T2 - Statusseminar RePhoR CY - Frankfurt a. M., Germany DA - 03.05.2023 KW - Phosphor KW - Recycling KW - Thermochemisch PY - 2023 AN - OPUS4-58480 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schulz, Anne-Christine A1 - Schreiber, Frank T1 - Co-selection for biocide and antibiotic resistance in microbial wastewater communities N2 - Biocides are used for a wide range of purposes, including disinfectants or preservatives. They play a major role in the prevention of microbial infections in healthcare and animal husbandry. The use of biocides often leads to the discharge of active biocidal substances into wastewater streams, causing the exposure of wastewater microbial communities to subinhibitory concentrations. In turn, it is known that wastewater treatment plants (WWTP) are hotspots for antibiotic resistant bacteria. Since similar mechanisms confer resistance to biocides and antibiotics, exposure to biocides can result in co-selection of antibiotic resistant bacteria in WWTP Here, we want to investigate co-selection processes of antibiotic resistance in natural WWTP microbial communities upon biocide exposure. Microbial communities were sampled at the WWTP Ruhleben in Berlin and characterized regarding their susceptibility against different clinically relevant antibiotics. To investigate the link between biocide exposure and antibiotic resistance, changes in the susceptibility level after exposure to environmentally relevant concentrations of the commonly used biocide didecyldimethylammonium chloride (DDAC) will be determined by enumerating resistant and non-resistant E. coli on selective plates with and without antibiotics and DDAC. In case of antibiotics, clinical breakpoint concentrations according to EUCAST will be used to discriminate between susceptible and resistant strains. In case of DDAC (and biocides in general), clinical breakpoints do not exist. Therefore, we determined a cut-off concentration at which the majority of naturally-occurring E. coli strains cannot grow anymore based on (I) the MIC (minimal inhibitory concentration) distribution, and (II) by plating wastewater communities onto selective indicator agar plates loaded with increasing DDAC concentration. Additionally, antibiotic cross-resistance will be determined by spotting single colonies, isolated from DDAC-selective plates onto antibiotic plates. The results of our experiments will help to determine selective concentrations and to estimate the risk of antibiotic co-selection and cross-resistance in microbial WWTP communities upon biocide exposure. T2 - Annual Conference 2023 of the Association for General and Applied Microbiology CY - Göttingen, Germany DA - 10.09.2023 KW - Antibiotic resisitance KW - Biocide KW - Wastewater KW - Risk assesment PY - 2023 AN - OPUS4-58510 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Razkin Bartolomé, Malen A1 - Gräf, S. A1 - Thiele, Dorothea A1 - Sahre, Mario A1 - Zabala, A. A1 - Buruaga, L. A1 - Krüger, Jörg A1 - Müller, F.A. A1 - Bonse, Jörn A1 - Schwibbert, Karin T1 - Bacterial adhesion on fs-laser processed laser-induced periodic surface structures N2 - Bacteria are ubiquitous and colonize all types of surfaces, including those in close proximity to humans, such as skin, food, and everyday objects. This raises the question of whether their presence represents a problem to be mitigated or a potential source of benefit to be harnessed, thereby stimulating scientific inquiry into the role of surface-associated bacteria in diverse domains ranging fromhuman health to industrial biotechnology. Aim: The objective of this project is to explore the impact of modifying surface topography on bacterial adhesion behavior. By manipulating the physical characteristics of the substrate, the attachment and detachment dynamics of bacteria can potentially be modified, leading to novel strategies for controlling bacterial colonization in various applications, such as medical devices. Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were tested on LIPSS-covered Fused Silica samples. T2 - 2023 Spring Meeting · , 2023 · Strasbourg CY - Strasbourg, France DA - 29.05.2023 KW - LIPSS KW - Biofilm KW - fs-laser processing PY - 2023 AN - OPUS4-58456 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dehkohneh, Abolfazl A1 - Gerrits, Ruben A1 - Schumacher, Julia A1 - Kreft, J.-U. A1 - Gorbushina, Anna T1 - Fungal biofilms on materials: describing and modelling growth of the black fungus Knufia petricola N2 - Fungi that grow as biofilms are associated with clinical settings as well as various cases of material fouling and material damage. Black fungi as biofilm formers have been rarely studied so far. Their conspicuous dark pigmentation, EPS production, adhesion capabilities and adaptations to stresses allow black fungi to develop biofilms on materials under harsh conditions. For example, rock-inhabiting black fungi withstand sun irradiation and dehydration and are therefore ubiquitous on arid surfaces like solar panels and marble monuments. To understand and control their ability to colonise and deteriorate materials, one should assess and model black fungi’s growth patterns. But so far, no mathematical model has been developed to describe their growth. Knufia petricola A95, representing rock-inhabiting fungi from Chaetothyriales, is genetically amenable and can serve as a model for biofilm studies in black fungi. The primary objective of this project is to develop a growth model for K. petricola A95 which will enable to define and predict material colonisation of black fungi. Dedicated experimental work with K. petricola will allow the quantitative assessment of the impact of environmental conditions (e.g. pH, nutrients, etc.) on the growth behaviour at the biofilm and single cells level. Data which will be used to validate and develop an individual-based model (based on the iDynoMICS modelling platform) that explains how fungal biofilms form, colonise materials, and cause deterioration. Thus far, research has been conducted on the impact of different concentrations and sources of major elements (e.g. C, N, …), as well as trace elements (e.g. Cu, Mg, …), on the colony shape and biomass of Knufia petricola A95 biofilms. To study the behaviour of single cells, the length of the cell cycle in different growth media has been determined via the combined use of microfluidic devices and confocal microscopy. T2 - IUBMB Focused Meeting on Extremophilic Fungi (FUN-EX) CY - Ljubljana, Slovenia DA - 19.09.2023 KW - Biofilm KW - Rock-inhabiting fungus KW - Mathematical modelling PY - 2023 AN - OPUS4-58438 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schumacher, Julia A1 - Brandhorst, Antonia A1 - Voigt, Oliver A1 - Nitsche, Sarah A1 - Erdmann, Eileen A1 - Gorbushina, Anna A1 - Schumacher, Julia T1 - DHN melanin – synthesis, regulation, and functions in Knufia petricola N2 - Dihydroxynaphthalene (DHN) melanin is produced by diverse Ascomycetes via slightly differing biosynthetic routes. The polyketide synthases (PKS) release the heptaketide YWA1, the hexaketide AT4HN or the pentaketide T4HN. The first two products are deacetylated by ‘yellowish-green’ hydrolases to T4HN, and T4HN is further converted by a core set of enzymes to DHN. Final polymerization steps are accomplished by multicopper oxidases. DHN melanogenesis is often regulated in a spatial and temporal fashion resulting e.g., in melanized reproduction and survival structures of the foliar plant pathogen Botrytis cinerea (Schumacher 2016, Mol Microbiol). In contrast, microcolonial black fungi exhibit constitutive melanogenesis. Here, DHN melanin builds a protective layer around all vegetative cells thus contributing to the survival of diverse environmental stresses even without specialized reproduction structures. For studying the regulation and relevance of DHN melanogenesis for tolerance of abiotic and biotic stresses, adhesion to substrates and subsequent damage of colonized surfaces, the rock-inhabiting fungus Knufia petricola was chosen as gene functions in this fungus can be studied by CRISPR/Cas9-based genome editing. The putative melanogenic genes were identified in the genome of K. petricola, deleted to confirm their involvement in DHN melanogenesis and co-expressed in Saccharomyces cerevisiae for reconstruction of the synthesis pathway. Phenotypes of deletion mutants are studied for specifying the functions of DHN melanin in K. petricola. T2 - IUBMB Focused Meeting on Extremophilic Fungi (FUN-EX) CY - Ljubliana, Slovenia DA - 19.09.2023 KW - Pigment KW - Fungus KW - Heterologous expression PY - 2023 AN - OPUS4-58430 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vogel, Christian A1 - Ronen, A. A1 - Leube, Peter A1 - Ben Efrain, R. A1 - Nir, O. A1 - Chaudhary, M. A1 - Futterlieb, M. A1 - Panglisch, S. T1 - Detection, quantification, and treatment of per- and polyfluoroalkyl substances (PFAS) in groundwater (DFEAT-PFAS) N2 - Over the past century, a range of synthetic compounds have been produced to improve humanity’s quality of life. These include pharmaceuticals, plastics, and other chemical compounds that possess properties making them potentially harmful when released to the environment (e.g., ecological and health impacts to humans and animals). Per- and polyfluoroalkyl substances (PFAS) are a large group of chemicals used in the formulations of thousands of consumer goods, including aqueous film-forming foams used to suppress aviation fires in training scenarios, non-stick cookware, fast-food wrappers, water-repellent fabrics, medical equipment, and plastic and leather products. Because of the recent regulations and restrictions on the use of long chain (≥C8) PFAS a significant shift in the industry towards short (C4-C7) and ultrashort (C1-C3) chain alternatives has been recognized the last years. Due to the high polarity and water solubility of ultrashort PFAS, the potential for bioaccumulation is low. However, the high persistence of ultrashort-chain PFAS will result in environmental accumulation, especially in aquatic environments, leading to potential risks for aquatic organisms and increased human external exposure through drinking water. Ultrashort PFAS like trifluoroacetic acid (TFA) are low to moderately toxic to a range of organisms. In addition, ultrashort PFAS can penetrate natural and anthropogenic barriers and eventually reach drinking water sources. Because common drinking water treatment techniques do not sufficiently remove them, they may reach human consumption. In the project we are focusing on detecting and removing PFAS, especially ultrashort-chain PFAS from contaminated groundwater. We are designing passive sampling devices, which can collect and monitor the temporal profile of PFAS species in groundwater. This will allow us to analyze PFAS contaminations in German and Israeli groundwater using state-of-the-art and novel analytical techniques and understand the extent of contamination. In addition to quantification, PFAS contaminated groundwater will be treated via a two-stage process to produce PFAS-free drinking water. As ultrashort-chain PFAS are difficult to analyze with the current target (LC-MS/MS) and sum parameter (AOF, EOF) analysis methods, we additionally using gas chromatography – mass spectrometry (GC-MS). Therefore, an analytical method based on GC-MS is in development to analyze the volatile ultrashort-chain PFAS (TFA, PFPrA, TFMS, PFEtS, PFPrS, trifluoroethanol, pentafluoropropanol and hexafluoro isopropanol) directly in contaminated groundwater samples with the headspace technique and in eluates of organic solvents from the developed passive sampler after direct injection. Moreover, a two-stages process is designed to increase the low concentrations found in groundwater using novel membranes processes such as closed-circuit reverse osmosis (CCRO) and mixed matrix composite nanofiltration membranes (MMCM). Next, the rejected streams containing higher concentrations of PFAS will be treated by coagulation, and the remaining PFAS adsorbed onto carbonaceous nanomaterials (CNMs). The DEFEAT-PFAS project will result in the development of novel tools to detect, quantify, and remove PFAS, especially ultrashort-chain PFAS from contaminated groundwater, and will acquire a new understanding of the extent of these contaminations. T2 - Dioxin Konferenz CY - Maastricht, Netherlands DA - 10.09.2023 KW - Ground water KW - Per- and Polyfluoroalkyl substances (PFAS) KW - Remediation PY - 2023 AN - OPUS4-58346 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wen, Keqing A1 - Gorbushina, Anna A. A1 - Schwibbert, Karin A1 - Bell, Jérémy T1 - A microfluidic platform for monitoring biofilm formation in flow under defined hydrodynamic conditions N2 - Bacterial adhesion on surfaces of medical, water and food applications may lead to infections, water or food spoilage and human illness. In comparison to traditional static and macro flow chamber assays for biofilm formation studies, microfluidic chips allow in situ monitoring of biofilm formation under various flow regimes, have better environment control and smaller sample requirements. In this work, a novel microfluidic platform is developed to investigate biofilm adhesion under precisely controlled bacteria concentration, temperature, and flow conditions. This platform central unit is a single-inlet microfluidic flow cell with a 5 mm wide chamber designed and tested to achieve ultra-homogenous flow in the central area of chamber. Within this area, defined microstructures are integrated that will disturb the homogeneity of the flow, thus changing bacterial adhesion pattern. Here we present the monitoring of bacterial biofilm formation in a microfluidic chip equipped with a microstructure known as micro-trap. This feature is based on a 3D bacteria trap designed by Di Giacomo et al. and successfully used to sequester motile bacteria. At first, fluorescent particles similar in size to Escherichia coli (E. coli) are used to simulate bacteria flow inside the flow cell and at the micro-trap. The turbulences induced by the trap are analyzed by imaging and particle tracking velocimetry (PTV). Secondly, the model strain E. coli TG1, ideal and well described for biofilm studies, is used to analyze biofilm formation in the micro-trap. Therefore, a stable fluorescent strain E. coli TG1-MRE-Tn7-141 is constructed by using Tn7 transposon mutagenesis according to the method described by Schlechter et al. Sequestering of E. coli cells within the micro-trap was followed using epifluorescence microscopy. The novel microfluidic platform shows great potential for assessment of bacterial adhesion under various flow regimes. The performance of structural feature with respect to the generation of turbulences that promote or reduce bacterial adhesion can be systematically examined. The combination of flow analysis and fluorescent strain injection into the microfluidic chip shows that the micro-trap is useful for capturing bacteria at defined positions and to study how flow conditions, especially micro-turbulences, can affect biofilm formation. It represents a powerful and versatile tool for studying the relation between topography and bacteria adhesion. T2 - International Conference on Miniaturized Systems for Chemistry and Life Sciences CY - Katowice, Poland DA - 15.10.2023 KW - Biofilm KW - E. coli KW - Microfluidics KW - Velocimetry KW - Fluorescence PY - 2023 AN - OPUS4-59593 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Cook, Jake Thomas A1 - Tonon, Chiara T1 - Assessment of concrete bioreceptivity in algal biofilm green façade systems N2 - Algal biofilm façades are an alternative to traditional green façades which can help to improve biodiversity and air quality within cities. They present a low maintenance approach in which subaerial algae are grown directly on concrete substrates. The intrinsic bioreceptivity of the substrate is a critical factor in successful facade colonisation. Existing research has identified several environmental and material properties which influence concrete bioreceptivity, however a consensus has yet to be made on which properties are most influential and how the interaction between properties may promote algal biofilm growth under specific conditions. T2 - International Conference on Bio-Based Building Materials CY - Vienna, Austria DA - 21.06.2023 KW - Concrete KW - Façade KW - Bio-receptive KW - Extracellular polymeric substances KW - Fractional factorial PY - 2023 UR - https://www.rilem.net/agenda/5th-international-conference-on-bio-based-building-materials-1501 AN - OPUS4-58976 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Keshmiri, Hamid T1 - Bidiffractive leaky-mode biosensor N2 - This study details a thorough analysis of leaky and waveguide modes in biperiodic diffractive nanostructures. By tuning diffraction orders and subsequently confining local density of optical states at two distinct resonance wavelengths, we present a highly sensitive refractive index biosensing platform that can resolve 35.5 to 41.3 nm/RIU of spectral shift for two separate biological analytes. T2 - EMBL Symposium: Seeing is Believing - Imaging the Molecular Processes of Life CY - Heidelberg, Germany DA - 04.10.2023 KW - Optics PY - 2023 AN - OPUS4-59247 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Keshmiri, Hamid T1 - Plasmon-enhanced diffractive supercells N2 - Multiple diffractive surface modulations can concurrently couple the light to several electromagnetic surface waves. We present a multi-resonant plasmonic supercell structure with a broad range of applicability in harvesting the light over an extensive wavelength range and angles of incidence. T2 - Molecular Plasmonics 2023 CY - Jena, Germany DA - 11.05.2023 KW - Optics PY - 2023 AN - OPUS4-59248 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Erdmann, Eileen A1 - Kunze, R. A1 - Gorbushina, Anna A1 - Schumacher, Julia T1 - A random mutagenesis approach to elucidate the biology of extremotolerant black fungi N2 - Microcolonial black fungi ubiquitously inhabit sun-exposed natural and man-made surfaces of our planet. To promote genetic studies, which are hindered by slow growth, lack of sexual cycles and transformation difficulties, CRISPR/Cas9-based genetic tools were implemented (Erdmann et al. 2022, Front Fungal Biol). Now efficient targeted mutagenesis of the rock inhabitant Knufia petricola (Eurotiomycetes/Chaetothyriales) - as a representative of the polyphyletic group of black fungi - enables the elucidation of extremotolerance, oligotrophism, unusual types of cell division, mineral weathering and symbiotic interactions. Still more progress on assigning functions to yet unknown genes can be expected if a forward genetics approach is available. We chose the two-component Activator/ Dissociation (Ac/Ds) transposon system from maize for generating a collection of insertional mutants by in-vivo mutagenesis of K. petricola. For the optimal use of this genetic tool, an inducible promoter for the expression of the Ac transposase (AcTPase) and by this the regulatable transposition of the resistance cassette-containing Ds transposon is desired. However, endogenous promoters for nitrate assimilation and galactose catabolism - often used in fungi for regulatable gene expression - are not inducible by their substrates in K. petricola suggesting that the regulatory networks for nutrient acquisition differ significantly in oligotrophic fungi. Therefore, the metabolism-independent Tet-on system was combined with the AcTPase coding sequence and subsequently transformed into Ds-carrying K. petricola strains. In total, four auxotrophic Ac|Ds starter strains containing the Ds transposon at different position of ade2 or ura3 were generated. The cultivation of these strains with doxycycline for induction of TET::Ac and subsequent selection of cells on ADE/URA-lacking media resulted in prototrophic colonies (revertants) for some but not all Ac|Ds strains. Currently, the transposition events in the obtained revertants are studied to validate the procedure. First amplicon sequencing of excision sites revealed footprint patterns, proving the transposon jumped. T2 - 16th European Conference on Fungal Genetics CY - Innsbruck, Austria DA - 05.03.2023 KW - Rock-inhabiting fungi KW - Foward genetics KW - In-vivo mutagenesis PY - 2023 AN - OPUS4-57144 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Catanzaro, Ilaria A1 - Nitsche, Sarah A1 - Gorbushina, Anna A1 - Schumacher, Julia A1 - Onofri, S. T1 - Understanding the role of DHN melanin in Cryomyces antarcticus N2 - Cryomyces antarcticus – a cryptoendolithic black fungus endemic to Antarctica – is taxonomically classified in phylum Ascomycota, class Dothideomycetes incertae sedis. C. antarcticus has shown high capability to survive extreme environmental conditions like those found in space (ionizing radiation, vacuum, microgravity), thus fueling fundamental astrobiological questions like “searching for life beyond Earth” (Onofri et al. 2020, Extremophiles Astrobiol Model). Its extraordinary resilience has been attributed to the presence of thick, highly melanized cell walls, which may contain both DHN and DOPA melanins (Pacelli et al. 2020, Appl Microbiol Biotechnol). To better understand the contribution of DHN melanin to the overall resilience of C. antarcticus, we initially adopted chemicals e.g., tricyclazole to inhibit the DHN melanin synthetic pathway; however, these studies gave inconclusive results. Eventually, we decided to generate melanin-deficient mutants by genetic engineering. Using the genetic toolkit developed for the black fungus Knufia petricola (Voigt et al. 2020, Sci Rep; Erdmann et al. 2022, Front Fungal Biol), we designed a strategy for mutating the key enzyme (polyketide synthase)-encoding gene capks1 by transient delivery of Cas9 and capks1-specific sgRNA from AMA-containing plasmids and PCR-generated donor DNA i.e., resistance cassettes flanked by ~75-bp-long sequences homologous to capks1. For this, the melanin-PKS encoding ortholog was identified in the C. antarcticus CBS 116301 genome (mycocosm.jgi.doe.gov) and used to design primers for re-sequencing of the capks1 locus in the strain CCFEE 515. Transformation of C. antarcticus is challenging because of its very slow growth; we expect that 4-6 months are needed from obtaining enough biomass for cell wall lysis until transferring putatively resistant transformants for genotyping. Important parameters were evaluated: protoplasts can be generated, and they survive the transformation procedure, and suitable concentrations of selective agents have been identified. Nowadays, we are waiting for the first C. antarcticus mutants considered to be deficient in DHN melanogenesis. T2 - 16th European Conference on Fungal Genetics CY - Innsbruck, Austria DA - 05.03.2023 KW - Cryptoendolithic black fungus KW - DHN melanin KW - Astrobiology PY - 2023 AN - OPUS4-57145 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Musyanovych, A. A1 - Grimmer, Christoph A1 - Sadak, A. E. A1 - Heßling, L. A1 - Bilsel, M. A1 - Horn, Wolfgang A1 - Richter, Matthias T1 - Polymeric Capsules with VOCs for Controlled Emission N2 - Micro-(nano-)encapsulation technology involves building of a barrier between the core and the environment and offers a number of benefits to preserve the functional and physicochemical properties of core material. Tremendous progress has been made in synthesizing well-defined capsules to achieve desired properties such as particle size, chemical composition, and controlled release of the payload. Encapsulation of volatile organic compounds (VOCs) that could evaporate with a defined rate is of immense interest for application in emission reference materials (ERM). These are urgently needed for quality assurance and quality control purposes (QA/QC) required by test standards for the determination of chemical emissions of construction and other materials for interior use. As such ERMs are hardly available on the market, the EU-funded EMPIR project MetrIAQ [1] was started to fill this gap by developing a material with temporally constant emission of VOCs typically found in indoor air. Different capsules in a size range between 5 and 50 μm were synthesized through an interfacial polyaddition/polycondensation reaction in direct (water-in-oil) system. As VOC several types of hydrophobic liquid materials were used. After synthesis, the morphology and physicochemical properties of capsules were characterized by electron microscopy, FTIR and DSC/TGA. An encapsulation efficiency up to 90% could be reached. The emission kinetic of volatile agents was studied in emission test chambers at 23 °C and 50% RH for 14 days. First results indicate that variation of the cross-linking grade of the shell material is one important parameter to adjust the desired emission rate. The overall aim is to achieve a consistent emission profile that decreases by less than 10 % over a target period of at least 14 days. T2 - 36th European Colloid & Interface Society Conference CY - Chania, Crete, Greece DA - 04.09.2022 KW - Capsules KW - Volatile organic compound KW - Polymer KW - Material emissions KW - Reference materials PY - 2022 AN - OPUS4-56039 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Musyanovych, A. A1 - Grimmer, Christoph A1 - Sadak, A. E. A1 - Heßling, L. A1 - Bilsel, M. A1 - Horn, Wolfgang A1 - Richter, Matthias T1 - Polymeric Capsules with VOCs for Controlled Emission N2 - Micro-(nano-)encapsulation technology involves building a barrier between the core and the environment and offers several benefits to preserve the functional and physicochemical properties of core material. Tremendous progress has been made in synthesizing well-defined capsules to achieve desired properties such as particle size, chemical composition, and controlled release of loaded compounds. Encapsulation of volatile organic compounds (VOCs) that could evaporate with a defined rate is of immense interest for application in emission reference materials (ERM). These are urgently needed for quality assurance and quality control purposes (QA/QC) required by test standards for the determination of chemical emissions of construction and other materials for interior use. As such ERMs are hardly available on the market, the EU-funded EMPIR project MetrIAQ was started to fill this gap by developing a material with temporally constant emission of VOCs typically found in indoor air. T2 - 36th European Colloid & Interface Society Conference CY - Chania, Crete, Greece DA - 04.09.2022 KW - Capsules KW - Volatile organic compounds KW - Material emissions KW - QA/QC KW - Reference materials PY - 2022 AN - OPUS4-55917 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strzelczyk, Rebecca A1 - Horn, Wolfgang A1 - Matthias, Richter A1 - Christoph, Grimmer T1 - Zeolites loaded with VOCs as reference for material emissions testing N2 - Nowadays, people spend most of their time indoors. Thus, a good indoor air quality is important. Emissions of volatile organic compounds (VOCs) from furniture and building materials can cause health complaints1. Quantitative VOC-emission testing is carried out under standardized conditions in emission test chambers. In the presented project an emission reference material (ERM) is developed that emits a defined mixture of VOCs which is required for quality assurance and -control (QA/QC) measures. Porous materials (e.g zeolites, activated carbons, MOFs or aerogels) are used as reservoir materials and impregnated with VOC. The porous materials are selected, among others, by their pore size, pore size distribution, polarity and availability. Due to their regular pore structure zeolites are tested at first. For a prediction of the emission profile, the ERM is supposed to exhibit a constant emission rate over time. The aim is a stability of ≤ 10 % change in the emission rate over a minimum of 14 days. Method For impregnation, the material is placed into an autoclave inside a rotatable basket. The VOC is added and the autoclave is closed. Afterwards, CO2 is inserted. The closed system is then heated to the supercritical point of CO2 (31 °C, 73.75 bar). In this state, the CO2 acts as solvent for the VOC. By rotating the basket, the distribution of the VOC is ensured. After a few minutes, the pressure is decreased slowly and the CO2 is released. For the determination of the emission profile, the impregnated sample is placed into an emission test chamber. These chambers can be operated either with dry or humid air (50 ± 5 % rel. humidity). Every second to third day, air samples are taken and analyzed by gas chromatography. For an ideal impregnation, several different pressures and temperatures as well as impregnation times are tested. Results Two zeolite materials tested in dry air conditions reach emission profiles with a decrease of less than 10 % over 14 days (heptane and toluene, respectively). Further it was discovered that smaller pellets of the same zeolite show better results than bigger particles. When the pore size of a zeolite is too small, e.g. 0.3 nm, the VOC cannot be absorbed sufficiently. The main disadvantage of zeolites is their hygroscopicity because it has a large impact on the release of VOC when they are used in emission test chambers under standardized test conditions (23 °C, 50 % rel. humidity). Activated carbons have emission profiles with a larger change over 14 days. However, the high hydrophobicity allows measurements in humid air conditions which was not possible with the before mentioned hygroscopic zeolites. It is possible to impregnate powdered materials as well, and thus powdered non-hygroscopic (n.h.) zeolites were impregnated. Their emission profiles are comparable to those of the activated carbons. The use of methylated hygroscopic zeolites with a decrease in hygroscopicity did not yield successful emission measurements. The change over 14 days is calculated only for the stable phase (~250–300 h). The desired stability of ≤ 10 % change of the emission rate over 14 days could already be reached under dry testing conditions. Further investigations under humid conditions show that zeolites with high Si/Al-ratios are non-hygroscopic and comparable to activated carbons (20–30 % change). The next step is to reduce the change in the emission rate of these materials to the aimed ≤ 10 % over 14 days. T2 - Deutsche Zeolithtagung CY - Jena, Germany DA - 28.02.2024 KW - VOC KW - Emission KW - Quality assurance KW - Reference material KW - Zeolite PY - 2024 AN - OPUS4-59843 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strzelczyk, Rebecca A1 - Horn, Wolfgang A1 - Matthias, Richter A1 - Christoph, Grimmer T1 - Constant emitting reference material for emissions test procedures N2 - Since nowadays people spend most of their time indoors, a healthy environment is essential. Volatile organic compounds (VOCs) emitted from furniture and building materials are reported to cause health complaints. Therefore, the usage of low emitting materials will improve the indoor air quality. Quantitative VOC emission testing is usually conducted in emission test chambers under specified controlled conditions as described in DIN 16000-9 and DIN EN 16516. For reasons of quality control/quality assurance (QC/QA) and for a better comparability of test results from different laboratories, suitable emission reference materials (ERM) are needed. Here, it is important to have a homogenous material with known emission rates over a specific time. Different approaches can be found in literature, inter alia polymer films loaded with the target compound to be released again, or a lacquer material to which a VOC mixture is added. After curing of the lacquer, the material can be loaded into a test chamber. Drawback of those approaches are their relatively fast decreasing emission profiles. For QC/QA purposes according to the test standards, VOC sources with constant emission profiles are desirable. The EU-funded research project MetrIAQ “Metrology for the determination of emissions of dangerous substances from building materials into indoor air” is working on a multi-component ERM with an envisaged instability of ≤ 10 % in the emission rate over at least 14 days. Within a doctoral thesis porous materials are impregnated with VOCs. Supercritical CO2 is used as solvent. Thus, the impregnated material does not contain any solvent that may show a measurable amount of emission in the emission test chamber. Furthermore, CO2 has the benefits to have a good availability and low costs. For the selection of porous materials several properties like the pore size, the surface, and the interaction with the components in the atmosphere need to be considered. The impregnation method is optimised while the different porous materials are tested. For the selection of porous materials the pores need to be large enough for the VOC molecules, further influence of the pore size is tested. T2 - Healthy Buildings CY - Aachen, Germany DA - 11.06.2023 KW - VOC KW - Emission KW - Quality assurance KW - Reference material PY - 2023 AN - OPUS4-59842 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Horn, Wolfgang A1 - Richter, Matthias A1 - Wilke, Olaf T1 - Volatile organic compounds from building products - Results from seven proficiency tests with emission test chambers conducted between 2008 and 2021 N2 - Emission testing of volatile organic compounds (VOC) from materials and products is commonly based on emission test chamber measurements. To ensure the comparability of results from different testing laboratories their measurement performance must be verified. For this purpose, Bundesanstalt für Materialforschung und -prüfung (BAM) organizes an international proficiency test every two years using well-characterised test materials (one sealant, one furniture board and four times a lacquer) with defined VOC emissions. The materials fulfilled the requirements of homogeneity, reproducibility, and stability. Altogether, 41 VOCs were included of which 37 gave test chamber air concentrations between 10 and 98 µg/m³. This is the typical concentration range to be expected and to be quantified when performing chamber tests. Four compounds had higher concentrations between 250 and 1105 µg/m³. The relative standard deviations (RSD) of BAM proficiency tests since 2008 are compared and the improvement of the comparability of the emission chamber testing is shown by the decrease of the mean RSD down to 23% in 2021. In contrast, the first large European interlaboratory comparison in 1999 showed a mean RSD of 51%. T2 - Proficiency Testing in Analytical Chemistry, Microbiology and Laboratory Medicine CY - Windsor, United Kingdom DA - 25.09.2023 KW - Proficiency Test KW - VOC-Emission KW - Chamber-test PY - 2023 AN - OPUS4-59694 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Brandt, S. A1 - Brozowski, F. A1 - Horn, Wolfgang A1 - Plehn, W. A1 - Müller, B. T1 - Odour Emissions from Building Products Simplifying the Evaluation of Perceived Intensity N2 - One criterion to evaluate the odour of a sample is perceived intensity П which is evaluated with the aid of a comparative scale. The procedure is well accepted but also time consuming and extensive. The study should help simplify the testing procedure by asking the panel members to only indicate whether a sample is perceived as less to equally intense or of greater intensity in comparison to a given acetone concentration of 7 pi on the comparative scale. In Germany a value of 7 pi is required for products to be suitable for the indoor use. The results show that the simplified test is basically suitable. T2 - Indoor Air Conference 2022 “Healthy people in healthy indoor environment” CY - Kuopio, Finland DA - 12.06.2022 KW - Perceived Intensity KW - Emissions KW - Chamber test KW - Odour KW - VOC KW - Building product PY - 2022 AN - OPUS4-55623 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Piechotta, Christian A1 - Köppen, Robert A1 - Becker, Roland A1 - Bücker, Michael A1 - Ostermann, Markus A1 - Traub, Heike T1 - Weathering scenarios – Changes in polymer surface morphologies and leaching of brominated flame retardants N2 - In addition to previously reported results on the simulated aging of polystyrene samples (PS) containing 1 wt. % hexabromocyclododecane (HBCD), we present the first results of our investigations of polypropylene (PP)-samples containing 0.1 wt. % BDE-209. All studied polymer samples were exposed to a defined weathering schedule in a climate chamber in accordance to regulation EN ISO 4892-3:2006.For the determination of BDE-209 in the collected rain water samples derived from the used climate chamber, the samples were prepared in accordance with a validated protocol. Before the analyses, each sample was spiked with 2 µL of isotopically labeled BDE-209 (13C10-BDE-209) to serve as internal standard (ISTD) in the performed stable isotope dilution analysis. Subsequently the samples were extracted with isooctane, the obtained aliquots of the extracts were concentrated to 200 µL and 2 µL of the resulting solution were injected to the GC/MS for quantification. Additionally, the total bromine contents are monitored for the aged and untreated samples using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) as well as X-ray fluorescence analysis (XRF) as non-destructive and rapid method. Furthermore, results from surface analysis using environmental scanning electron microscopy (ESEM) for morphological characterization of the aged and untreated samples were presented and discussed. In general, the resulting data from the accelerated aging will be compared to those from the natural weathering experiments (“atmospheric exposure”, in soil). The atmospheric exposure was performed by placing the samples on a weathering rack, which is aligned in SW direction (in a 45° angle to the horizon). The weathering data were regularly recorded by Deutscher Wetterdienst at this site. The surfaces of the test specimens (aged and stored references) were analyzed by ESEM as well as by LA-ICP-MS and by XRF. The surface of PS and PP specimens aged outdoors present the aging under real conditions and allow the comparison to the accelerated aged specimens by means of the weathering chamber. This way, we explore the efficiency of the accelerated aging procedure, which provides the advantage of well-defined and reproducible conditions compared to natural weathering, as a tool for testing different plastic materials. Additionally “in soil” experiments were conducted in-door in a well characterized testing soil. The soil (boulder-clay, sand with 12 % loam, particle size in total 0.2-4 mm) is filled in a free-draining concrete basin inside of an air-conditioned room. In this manner, TOC, water capacity and humidity are recorded parameters. To assure a washing out process from the samples by the raining water, the target water content is calculated to 8%. The actual humidity is measured by a tensiometer, assuring the duration of the raining period. The water content is additionally monitored by weight of the basin, capturing water from raining periods. The correct humidity is a fundamental parameter for biological activity. Samples of PS resp. PP were of dimension 10x1cm and 5 specimens were placed up to the half in the soil per basin. Microbial activity of the soil, monitored by the reference polyurethane, sets HBCD resp. BDE-209 of the samples free and will be leached from the samples by raining water. Thereafter these will be captured by passive samplers placed in a distinct distance to the samples in the soil. The “in soil” experiments are complementary to the weathering experiments due to the biological activity in the soil. These experiments simulate the fate of the brominated flame retardants in the biosphere. T2 - Umwelt 2018 CY - Münster, Germany DA - 09.09.2018 KW - BFR KW - Weathering KW - PP KW - PS PY - 2018 AN - OPUS4-47029 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schumacher, Julia A1 - Brandhorst, Antonia A1 - Erdmann, Eileen A1 - Nitsche, Sarah A1 - Voigt, Oliver A1 - Gorbushina, Anna T1 - DHN melanin synthesis in the rock inhabitant Knufia petricola N2 - DHN (1,8-dihydroxynaphthalene) melanin is produced by Ascomycetes via slightly differing synthetic routes. Polyketide synthases release YWA1, AT4HN or T4HN. YWA1 and AT4HN are deacetylated by ‘yellowish-green’ hydrolases, and T4HN is converted by a core set of enzymes to DHN. Final polymerization steps are accomplished by multicopper oxidases. The melanogenic genes are tightly, partially or not clustered in the genomes, and are often regulated in a spatial and/or temporal fashion. By contrast, microcolonial fungi/black yeasts – a polyphyletic group of Ascomycetes dwelling in hostile habitats such as bare rock surfaces – feature constitutive DHN melanogenesis. Here, we report on the DHN melanogenic genes of Knufia petricola (Eurotiomycetes/Chaetothyriales). T2 - 16th European Conference on Fungal Genetics CY - Innsbruck, Austria DA - 05.03.2023 KW - DHN melanin KW - Fungus KW - Biosynthesis PY - 2023 AN - OPUS4-57143 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Selina A1 - Schreiber, Frank A1 - Boenke, Viola A1 - Nordholt, Niclas A1 - Kanaris, Orestis A1 - Sündermann, Claudia T1 - Bacterial resistance evolution towards disinfectants and antimicrobial surfaces and development of a standardized test N2 - Question Disinfectants and antimicrobial surfaces (AMCs) are important tools to prevent the spread of pathogens and antimicrobial resistant bacteria. However, concerns have been raised about the possibility for the evolution and selection of resistance against disinfectants and AMCs. In turn, resistance against disinfectants and AMCs can be associated to antibiotic resistance due to cross-resistance - a single mechanism conferring resistance to a disinfectant and an antibiotic- and co-resistance - two distinct mechanisms physically linked on e.g. a plasmid. The risk for resistance and cross-resistance during use of biocides (including disinfectants and AMCs) must be evaluated during authorization according to the EU biocidal product regulation. However, to date there is a lack of standardized methods that support risk assessment during the authorization process. Methods We used adaptive laboratory evolution (ALE) experiments which are based on repeated exposure of bacteria to disinfectants or AMCs. The experiments are followed by phenotypic (antimicrobial susceptibility testing) and genotypic (whole genome sequencing) characterization of the evolved strains. The basic idea of these experiments is to expose bacteria to lethal conditions and select for mutants with increased survival. This approach is fundamentally different to other ALE experiments, which commonly select for increased growth at subinhibitory concentrations. However, selection for increased survival represents a selective pressure that more realistically reflects selection under in-use conditions of disinfectants and AMCs. Results First, we studied adaptation of E. coli during repeated disinfection with benzalkonium chloride in a suspension assay. The experiments showed a 2000-fold increase in survival within 5 exposure cycles. The adaptive changes are linked to highly parallel mutations in genes related to lipid A biosynthesis, less negative cell surface charge, reduced growth rate and increased competitive ability in the presence of certain antibiotics. We use the same approach to develop standardizable ALE experiments based upon accepted standards that are used to determine the efficacy of disinfectants (EN 13697) and antimicrobial surfaces (ISO 22196). The results highlight pronounced adaptation of different test strains towards surface disinfection (benzalkonium chloride and isopropanol) and AMCs (copper). Conclusion Bacteria can adapt with increased survival towards lethal stress imposed by disinfectants and AMCs. The adaptive ability of bacteria to disinfectants and AMCs can be determined in a standardized manner. T2 - 74. Jahrestagung der Deutschen Gesellschaft für Hygiene und Mikrobiologie [DGHM] e. V. CY - Berlin, Germany DA - 05.09.2022 KW - Antimicrobial surfaces KW - ISO22196 KW - Antimicrobial resistance KW - Round robin test PY - 2022 AN - OPUS4-56432 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schreiber, Frank A1 - Nordholt, Niclas A1 - Schmidt, Selina A1 - Lewerenz, Dominique T1 - Persistence as a microbial survival strategy against biocides and its link to antibiotic resistance evolution N2 - Background: One cornerstone to prevent the spread of antibiotic resistant bacteria in clinical settings is the application of disinfectants. However, bacteria can evolve resistance to disinfectants, which in turn can confer cross-resistance to antibiotics. Additionally, clonal bacterial populations can display phenotypic heterogeneity with respect to the tolerance of antibiotic stress leading to a prolonged survival of a sub-population; this phenomenon is termed persistence. Persistence to antibiotics is an evolvable trait and can serve as a stepping stone for the evolution of genetically encoded resistance. Until now, there is a lack of systematic studies that investigate if bacterial populations establish persister subpopulations that tolerate disinfectant stress longer than most of the population. Objectives: Our objective is to investigate if persistence is a bacterial survival strategy against disinfectants. Furthermore, we investigate the mechanisms of disinfectant persistence and if persistence can evolve in the face of fluctuating exposure to disinfectants. Lastly, we test if the evolved mechanisms of disinfectant tolerance lead to disinfectant resistance and if they confer cross-tolerance and cross-resistance against antibiotics. Methods: We use time-kill assays in the presence of disinfectants and experimental evolution combined to whole-genome sequencing in the model organism E. coli. Results: We find persister sub-populations against chlorhexidine and quaternary ammonium compounds, but not to alcohols, aldehydes and oxidative compounds. We will present the relationship of mechanisms known to underlie antibiotic persister formation to the formation of persisters against disinfectants. In addition, we will present data from an ongoing evolution experiment for persistence against disinfectants. T2 - 8th Congress of European Microbiologists - FEMS 2019 CY - Glasgow, UK DA - 07.11.2019 KW - Antimicrobial resistance KW - Biocides KW - Persister cells PY - 2019 AN - OPUS4-49081 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schreiber, Frank A1 - Nordholt, Niclas A1 - Pietsch, Franziska A1 - Heidrich, Gabriele A1 - Ciok, Michal T1 - Physiological and evolutionary consequences of exposing Pseudomonas aeruginosa to biocide-antibiotic combinations N2 - Antimicrobials can exert specific physiological effects when used in combination that are different from those when applied alone. These effects include physiological effects (i.e. synergy, antagonism and suppression) as well as evolutionary effects on the selection of resistant strains (i.e. cross-resistance and collateral sensitivity). While combination effects have been extensively mapped for antibiotic-antibiotic combinations, the combination effects of antibiotics with antimicrobials used as biocides or antiseptics have not been systematically investigated. Here, we investigated the physiological and evolutionary consequences of combinations of antibiotics (meropenem, gentamicin and ciprofloxacin) and substances used as biocides or antiseptics (octenidine, benzalkonium chloride, cetrimonium bromide, chlorhexidine, povidone-iodine, silver) on growth and selection of Pseudomonas aeruginosa. We find prevalent physiological combination effects with synergy occurring 6 times and antagonism occurring 10 times. The effects are specific to the antibiotic-biocide combination with meropenem showing a tendency for antagonism with biocides (6 of 7), while gentamicin has a tendency for synergy (5 of 7). A particular strong antagonism is apparent for the meropenem-chlorhexidine combination, for which we conducted an in-depth study on the underlying molecular mechanism using RNASeq. Moreover, we find widespread effects of the biocide-antibiotic combinations on selection of P. aeruginosa strains resistant to the antibiotics, including cross-resistance and collateral sensitivity. In conclusion, antibiotics and biocides or antiseptics exert physiological and evolutionary combination effects on the pathogen P. aeruginosa. These effects have consequences for the efficacy of both types of substances and for the selection of antimicrobial resistant strains in clinical applications with combined exposure (e.g. wound care, coated biomaterials). T2 - ASM-FEMS World Microbe Forum CY - Online meeting DA - 20.06.2021 KW - Antimicrobial resistance KW - Antagonism KW - Biofilms PY - 2021 AN - OPUS4-53165 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nordholt, Niclas A1 - Gustiherdini, Cahyaruri A1 - Lewerenz, Dominique A1 - Kanaris, Orestis A1 - Schreiber, Frank T1 - The disinfectant glutaraldehyde induces antibiotic tolerance N2 - Glutaraldehyde is widely used as a disinfectant and preservative, but little is known about its effects on bacterial susceptibility to antibiotics and the selection of tolerant phenotypes. We found that short-term exposure to sub-inhibitory levels of glutaraldehyde makes E. coli resistant to high doses of bactericidal antibiotics from different classes. This tolerance is associated with delayed, heterogeneous regrowth dynamics and global transcriptome remodeling. We identified over 1200 differentially expressed genes, including those related to antibiotic efflux, metabolic processes, and the cell envelope. The cells entered a disrupted state likely due to the unspecific mode-of-action of glutaraldehyde. Despite this unregulated response, we identified several differentially expressed genes not previously associated with antibiotic tolerance or persistence that induce antibiotic tolerance when overexpressed alone. These findings highlight how the unspecific mode-of-action of disinfectants can make bacteria temporarily resistant to antibiotics. They have implications for settings where disinfectants and antibiotics are used in close proximity, such as hospitals and animal husbandry, and for the selection dynamics of tolerant pheno- and genotypes in fluctuating environments where microorganisms are exposed to these substances, such as sewage systems. A trade-off arises from overcoming the disrupted state as quickly as possible and maintaining antibiotic tolerance. T2 - Gordon Research Conference - Molecular Mechanisms in Evolution CY - Easton, Massachusetts, United States DA - 25.06.2023 KW - Glutaraldehyde KW - Biocides KW - Tolerance KW - Bacteria KW - Disinfection KW - Heterogeneity KW - Antibiotics PY - 2023 AN - OPUS4-58033 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kanaris, Orestis A1 - Nordholt, Niclas A1 - Schreiber, Frank T1 - Consequences of benzalkonium chloride tolerance in Escherichia coli: Effects on selection and evolution in the presence of ciprofloxacin N2 - We investigated the selection dynamics between a benzalkonium chloride (BAC)-tolerant Escherichia coli strain (S4) and a sensitive wild type under four conditions: in the absence of antibiotics and in the presence of three different sub-inhibitory concentrations of the antibiotic ciprofloxacin in liquid cultures. The wild type was selected over the BAC-tolerant strain in the absence of antibiotics, while the opposite was observed at all ciprofloxacin concentrations investigated.Furthermore, we assessed the evolvability of resistance of the two strains to inhibitory concentrations of ciprofloxacin by performing a serial dilution evolution experiment with gradually increasing ciprofloxacin concentrations. The wild type had a higher probability to develop resistance to ciprofloxacin than the tolerant strain. By the end of the evolution experiment both strains evolved to grow at the highest ciprofloxacin concentration investigated, which was 2048 ×MIC of the wild type. T2 - 6th international symposium on the environmental dimention of antibiotic resistance-EDAR 6 CY - Gothenburg, Sweden DA - 22.09.2022 KW - Antimicrobial resistance KW - Tolerance KW - Experimental evolution KW - Selection PY - 2022 AN - OPUS4-56808 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schreiber, Frank A1 - Nordholt, Niclas A1 - Schmidt, Selina A1 - Lewerenz, Dominique T1 - Persistence as a microbial survival strategy against biocides and its link to antibiotic resistance evolution N2 - Question: One cornerstone to prevent the spread of bacteria in clinical and industrial settings is the application of biocides including disinfectants and preservatives. However, bacteria can evolve resistance to biocides, which in turn can confer cross-resistance to antibiotics. Additionally, clonal bacterial populations can display phenotypic heterogeneity with respect to the tolerance of antibiotic stress leading to a prolonged survival of a sub-population; this phenomenon is termed persistence. Persistence to antibiotics is an evolvable trait and can serve as a stepping stone for the evolution of genetically encoded resistance. Until now, there is a lack of systematic studies that investigate if bacterial populations establish persister subpopulations that tolerate disinfectant stress longer than most of the population. Our objective is to investigate if persistence is a bacterial survival strategy against biocides. Furthermore, we investigate the mechanisms of biocide persistence and if persistence can evolve in the face of fluctuating exposure to biocides. Lastly, we test if the evolved mechanisms of biocide tolerance lead to biocide resistance and if they confer cross-tolerance and cross-resistance against antibiotics. Methods: We use time-kill assays in the presence of biocides and experimental evolution combined to whole-genome sequencing in the model organism E. coli. Results: We find persister sub-populations against chlorhexidine and quaternary ammonium compounds, but not to alcohols, aldehydes and oxidative compounds. We will present the relationship of mechanisms known to underlie antibiotic persister formation to the formation of persisters against biocides. In addition, we will present data from an ongoing evolution experiment for persistence against biocides. Conclusion There is a link between antibiotic and biocide persistence with possible implications for antibiotic resistance evolution and spread. T2 - 5th International Symposium on the Environmental Dimension of Antibiotic Resistance - EDAR 2019 CY - Hong Kong, China DA - 09.06.2019 KW - Antimicrobial resistance KW - Biocides KW - Persister cells PY - 2019 AN - OPUS4-49083 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sobisch, Lydia-Yasmin A1 - Nordholt, Niclas A1 - Lewerenz, Dominique A1 - Schreiber, Frank T1 - Time-kill kinetics reveal heterogeneous tolerance to disinfectants N2 - Background. Disinfection is an important mitigation strategy to control and prevent the spread of infections. Incomplete or incorrect usage of disinfection may promote evolution of resistance against disinfectants and antibiotics. Ideally, disinfection reduces the number of surviving bacteria and the chance for resistance evolution. Resistance describes the ability to grow in previously inhibitory concentrations of an antimicrobial, whereas tolerance is associated with enhanced survival of lethal doses. Individual bacteria from the same population can display considerable heterogeneity in their ability to survive treatment (i.e. tolerance) with antimicrobials, which can result in unexpected treatment failure. Objective. In this study, we investigated six active substances of disinfectants, preservatives, and antiseptics against a population of E. coli to identify the presence of a tolerant subpopulation. Methods. We performed time-kill experiments and analyzed the data with a mathematical model to statistically infer whether the data is best explained by the presence of a tolerant subpopulation. Results. The analysis identified bimodal kill kinetics for benzalkonium chloride, didecyldimethylammonium chloride, and isopropanol. In contrast, kill kinetics by chlorhexidine, glutaraldehyde, and hydrogen peroxide were best explained by unimodal kill kinetics. These findings have implications for the risk of disinfection failure. In addition, we are currently performing adaptive laboratory evolution (ALE) experiments with the different disinfectants to investigate the potential consequences of tolerant sub-populations for the evolution of antimicrobial resistance and tolerance. T2 - Vereinigung Allgemeiner und Angewandter Mikrobiobiologie Jahreskongress 2023 CY - Göttingen, Germany DA - 10.09.2023 KW - Biocide KW - Desinfectant KW - E.coli PY - 2023 AN - OPUS4-58470 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sobisch, Lydia-Yasmin A1 - Nordholt, Niclas A1 - Lewerenz, Dominique A1 - Schreiber, Frank T1 - Time-kill kinetics reveal heterogeneous tolerance to disinfectants N2 - Background. Disinfection is an important mitigation strategy to control and prevent the spread of infections. Incomplete or incorrect usage of disinfection may promote evolution of resistance against disinfectants and antibiotics. Ideally, disinfection reduces the number of surviving bacteria and the chance for resistance evolution. Resistance describes the ability to grow in previously inhibitory concentrations of an antimicrobial, whereas tolerance is associated with enhanced survival of lethal doses. Individual bacteria from the same population can display considerable heterogeneity in their ability to survive treatment (i.e. tolerance) with antimicrobials, which can result in unexpected treatment failure. Objective. In this study, we investigated six active substances of disinfectants, preservatives, and antiseptics against a population of E. coli to identify the presence of a tolerant subpopulation. Methods. We performed time-kill experiments and analyzed the data with a mathematical model to statistically infer whether the data is best explained by the presence of a tolerant subpopulation. Results. The analysis identified bimodal kill kinetics for benzalkonium chloride, didecyldimethylammonium chloride, and isopropanol. In contrast, kill kinetics by chlorhexidine, glutaraldehyde, and hydrogen peroxide were best explained by unimodal kill kinetics. These findings have implications for the risk of disinfection failure. In addition, we are currently performing adaptive laboratory evolution (ALE) experiments with the different disinfectants to investigate the potential consequences of tolerant sub-populations for the evolution of antimicrobial resistance and tolerance. T2 - FEMS Conference CY - Hamburg, Germany DA - 10.07.2023 KW - Biocide KW - Desinfectant KW - E.coli PY - 2023 AN - OPUS4-58471 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schreiber, Frank A1 - Nordholt, Niclas A1 - Kanaris, Orestis A1 - Schmidt, Selina T1 - Persistence against benzalkonium chloride promotes rapid evolution of tolerance under periodic disinfection N2 - Biocides used as disinfectants are important to prevent the transmission of pathogens, especially during the current antibiotic resistance crisis. This crisis is exacerbated by phenotypically tolerant persister subpopulations which can survive transient antibiotic treatment and facilitate resistance evolution. Despite the transient nature of disinfection, knowledge concerning persistence to disinfectants and its link to resistance evolution is currently lacking. Here, we show that E. coli displays persistence against a widely used disinfectant benzalkonium chloride (BAC). Periodic, persister-mediated failure of disinfection rapidly selects for BAC tolerance. BAC tolerance is associated with reduced cell surface charge and mutations in the novel tolerance locus lpxM. Moreover, the fitness cost incurred by BAC tolerance turned into a fitness benefit in the presence of antibiotics, suggesting a selective advantage of BAC-tolerant mutants in antibiotic environments. Our findings provide a mechanistic underpinning for the faithful application of disinfectants to prevent multi-drug-resistance evolution and to steward the efficacy of biocides and antibiotics. T2 - New Approaches and Concepts in Microbiology CY - Online meeting DA - 07.07.2021 KW - Persistence KW - Biocides KW - Evolution KW - Cross-resistance KW - Biocide tolerance PY - 2021 AN - OPUS4-53168 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schreiber, Frank A1 - Nordholt, Niclas A1 - Kanaris, Orestis A1 - Schmidt, Selina A1 - Lewerenz, Dominique T1 - Phenotypic and evolutionary responses of bacteria to disinfection N2 - Disinfectants are important to prevent the transmission of pathogens, especially in the face of the current antibiotic resistance crisis. The crisis is further exacerbated by phenotypically tolerant persister subpopulations that can survive transient antibiotic treatment and facilitate resistance evolution. Despite the transient nature of disinfectant application, persistence to disinfectants and its role for the evolution of tolerance and cross-resistance to antibiotics has not been studied. Our work shows that E. coli displays persistence against several widely used disinfectants, including benzalkonium chloride (BAC), didecyldimethylammoniumchlorid (DDAC) and isopropanol. The molecular mechanism of BAC persistence is triggered in stationary phase and affected by several antibiotic persister genes (hipA, tisB, tolC, relA, spoT). Experimental evolution and population dynamic modeling show that repeated failure of disinfection due to persisters rapidly selects for BAC tolerance underpinned by reduced cell surface charge due to mutations in genes related to lipid A acylation (lpxML). Furthermore, evolved BAC tolerance affects the susceptibility to antibiotics, leading to positive selection of disinfectant tolerant strains at environmentally relevant antibiotic concentrations and variations in evolvability of antibiotic resistance due to epistatic effects. These results highlight the need for faithful application of disinfectants to steward their efficacy and the efficacy of antibiotics. A better understanding of the bacterial response to disinfectants is crucial to understand and avert the ongoing antimicrobial resistance crisis. T2 - Gordon Research Conference - Molecular mechanisms of evolution CY - Easton, MA, United States DA - 25.06.2023 KW - Antimicrobial resistance KW - Bacteria KW - Disinfection KW - Biocides PY - 2023 AN - OPUS4-57861 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nordholt, Niclas A1 - Lewerenz, Dominique A1 - Schmidt, Selina A1 - Schreiber, Frank T1 - Heterogeneity in the bacterial response to disinfection and its impact on antibiotic tolerance and resistance N2 - The global rise of antibiotic resistance has made the proper use of disinfectants more important than ever. Their application in clinical l settings is an integral part of antibiotics stewardship by preventing the occurrence and spread of infections. However, improper use of disinfectants also harbours the risk for the evolution of tolerance and resistance to disinfectants, but also to antibiotics. It is therefore crucial to understand whether and how bacteria can survive chemical disinfection and which conditions facilitate the evolution of tolerance and resistance. Here, we study the heterogeneity in the response of isogenic E. coli populations exposed to different levels of commonly used disinfectants. At concentrations below the minimal inhibitory concentration (MIC), we find that certain disinfectants induce prolonged lag times in individual cells, a phenotype that has been associated with persistence against antibiotics. At concentrations above the MIC, we find heterogeneous killing for a range of the tested substances. Interestingly, for the three cationic surfactants that were tested, we find kill kinetics revealing the presence of a tolerant subpopulation that can withstand disinfection longer than most of the population. We will present results from an ongoing evolution experiment in which we test the potential for evolution of population-wide tolerance and resistance through intermittent exposure to lethal doses of a cationic surfactant. T2 - New Approaches and Concepts in Microbiology CY - Heidelberg, Germany DA - 10.07.2019 KW - Persistence KW - Biocides KW - Resistance KW - heterogeneity KW - Bacteria PY - 2019 AN - OPUS4-48524 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ben Efraim, R. A1 - Vogel, Christian A1 - Leube, Peter A1 - Nir, O. A1 - Chaudhary, M. A1 - Futterlieb, M. A1 - Panglisch, S, A1 - Ronen, A, T1 - Comparison of PFAS Adsorption and Electro-Sorption Using Pristine and Functionalized MWCNTs N2 - Per- and polyfluoroalkyl substances (PFAS) have been extensively utilized in various industrial processes, resulting in elevated concentrations in landfills and drinking water reservoirs. Despite recognizing that shortchained PFAS are harmful, they are often overlooked. Short-chain PFAS are more challenging to remove via adsorption and membrane separation processes, and their detection is complex, thus creating a critical gap in understanding their environmental impact. To improve their environmental monitoring, we aim to improve short-chain PFAS adsorption and electro-sorption on novel carbon-based adsorbers such as pristine and functionalized multi-walled carbon nanotubes (MWCNTs) and assess their adsorption mechanisms. Based on the obtained result, we aim to develop a PFAS passive sampling device. T2 - German Israeli Water Technology Status Seminar CY - Koblenz, Germany DA - 18.06.2024 KW - Ground water KW - Per- and Polyfluoroalkyl substances (PFAS) KW - Sorption PY - 2024 AN - OPUS4-60329 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nordholt, Niclas A1 - Broska, Selina A1 - Schreiber, Frank T1 - Persistence as a microbial survival strategy against disinfectants N2 - Antimicrobial resistance is a major threat to human health. The prevalence of multi-drug resistant (MDR) bacteria is predicted to increase in the future requiring robust control strategies. One cornerstone to prevent the spread of MDR bacteria in clinical settings is the application of disinfectants to improve hygiene standards. However, bacteria can evolve resistance to disinfectants, which in turn can confer cross-resistance to antibiotics. Additionally, clonal bacterial populations can display phenotypic heterogeneity with respect to the tolerance of antibiotic stress leading to a prolonged survival of a sub-population; this phenomenon is termed persistence. Persistence to antibiotics is an evolvable trait and can serve as a stepping stone for the evolution of genetically encoded resistance. Until now, there is a lack of systematic studies that investigate if bacterial populations establish persister subpopulations that tolerate disinfectant stress longer than the majority of the population. Our results in E. coli indicate that persistence is a bacterial survival strategy against benzalkonium chloride, a widely used disinfectant. In future experiments, we will investigate the evolution of persistence in the face of fluctuating exposure to disinfectants and whether persistence facilitates resistance against disinfectants. Lastly, we will test how tolerance and resistance against disinfectants affects susceptibility against antibiotics. T2 - Bridging Ecology and Molecular Biology: Organismic Responses to Recurring Stress CY - Berlin, Germany DA - 09.04.2018 KW - Bacteria KW - Persistence KW - Resistance KW - Biocides PY - 2018 AN - OPUS4-44667 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Seeger, Stefan A1 - Pollakowski-Herrmann, Beatrix A1 - Osan, J. A1 - Gross, A. A1 - Stosnach, H. A1 - Kayser, Y. A1 - Beckhoff, B. T1 - Quantification of element mass concentrations in aerosols by combination of cascade impactor sampling and in-situ TXRF Spectroscopy N2 - A mobile Bruker S2 Picofox TXRF spectrometer has been used in two field campaigns within the EMPIR env07 AEROMET project for the on-site analysis of cascade impactor aerosol samples.The results show that even at moderate air pollution levels – i.e.PM10 fairly below 20 μg/m³ - element mass concentrations in air in the range of 100 pg/m³could be measured in up to 13 size bins after sampling times of less than only 0.5 days. T2 - UFP 2019 Ultrafeinstaub in der Atmosphäre und in Innenräumen, 3. Symposium CY - Technische Universität Berlin, Germany DA - 19.09.2019 KW - TXRF ambient air aerosol chemical analysis aerosol element composition KW - Aerosol KW - TXRF KW - Cascade impactor KW - Aerosol element alanysis KW - Aerosol element mass concentration PY - 2019 AN - OPUS4-49580 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Völzke, Jule L. A1 - Hodjat Shamami, Parya A1 - Gawlitza, Kornelia A1 - Feldmann, Ines A1 - Zimathies, Annett A1 - Meyer, Klas A1 - Weller, Michael G. T1 - Corundum as a novel affinity platform for the isolation of human IgG from plasma N2 - Nonporous corundum powder was functionalized covalently with protein binders to isolate and enrich specific proteins from complex matrices.The common crosslinker glutaraldehyde was compared with a hyperbranched polyglycerol (PG) of around 10 kDa. The latter was oxidized with periodate to generate aldehyde groups that can covalently react with the amines of the surface and the amino groups from the protein via a reductive amination process. The amount of bound protein was quantified via aromatic amino acid analysis (AAAA). As a proof of concept, IgG was extracted with protein A from crude human plasma. The advantages of corundum include the very low price, extremely high physical and chemical stability, pressure resistance, favorable binding kinetics, convenient handling, and flexible application. T2 - Adlershofer Forschungsforum 2022 CY - Berlin, Germany DA - 11.11.2022 KW - Affinity support KW - Affinity chromatography KW - Affinity extraction KW - Phosphonic acids KW - Polyglycerol KW - Reductive amination KW - Amino acid analysis KW - Tyrosine KW - Protein quantification KW - SDS-PAGE KW - Antibodies KW - Antibody purification KW - Downstream processing KW - Bovine serum albumin KW - BSA KW - Protein a KW - TEM KW - ESEM KW - Aluminum oxide KW - Sapphire KW - Human plasma KW - Protein immobilization KW - Protein hydrolysis KW - Glutaraldehyde KW - Aromatic amino acid analysis AAAA PY - 2022 AN - OPUS4-56154 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nordholt, Niclas A1 - Kanaris, Orestis A1 - Schmidt, Selina B. I. A1 - Schreiber, Frank T1 - Persistence against benzalkonium chloride promotes rapid evolution of tolerance under periodic disinfection N2 - The exposure to antimicrobial substances drives the evolution of antimicrobial resistance (AMR). Biocides are antimicrobials used as disinfectants, antiseptics and preservatives. They find application on a large scale in the industrial and medical sector, but also in private households. In terms of mass, the worldwide use of biocides exceeds that of antibiotics. Thus, despite their important role in preventing the spread of pathogens, due to their ubiquity, biocides are suspected to be drivers of the antimicrobial resistance crisis. In our work we try to understand how biocides contribute to the emergence of AMR, what the underlying adaptation principles and mechanisms are and how they compare to those found for antibiotics. Here, I present results which demonstrate that phenotypic heterogeneity in E. coli, namely the formation of tolerant persister cells, can enable the survival of disinfection and consequentially facilitate the evolution of AMR. Using experimental evolution that selects for tolerance, we find that mutations in lipid A biosynthesis arise following periodic treatment with benzalkonium chloride (BAC), a widely used disinfectant. BAC tolerance is associated with additional, diverse mutations as well as changes in the susceptibility to antibiotics from different classes and changes in motility and biofilm formation, suggesting extensive regulatory re-wiring in the evolved clones. Remarkably, we find that fitness costs (growth rate reduction) incurred by BAC tolerance are alleviated in the presence of antibiotics. These findings demonstrate the complexity underlying the adaptation to antimicrobials and highlight the links between persistence to disinfectants and resistance evolution to antimicrobials. T2 - Bacterial Networks (BacNet22) CY - Sant Feliu de Guixols, Spanien DA - 04.09.2022 KW - Persistence KW - Biocides KW - evolution KW - disinfection KW - biocide tolerance PY - 2022 AN - OPUS4-55713 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nordholt, Niclas A1 - Kanaris, Orestis A1 - Lewerenz, Dominique A1 - Gödt, Annett A1 - Schreiber, Frank T1 - Evolutionary implications of heterogeneous disinfectant tolerance N2 - Introduction: Effective disinfection is crucial to maintain hygiene and to prevent the spread of infections. Phenotypic heterogeneity in disinfection survival (i.e. tolerance) may result in failure of disinfection, which in turn may foster the evolution of resistance to both disinfectants and antibiotics. However, the consequences of phenotypic heterogeneity for disinfection outcome and resistance evolution are not well understood. Goal: This study investigates the impact of phenotypic heterogeneity on the survival and evolution of Escherichia coli during disinfection with six commonly used substances. Furthermore, the consequences of evolved disinfectant tolerance for antibiotic resistance evolution are studied. Materials & Methods: The extent of population heterogeneity during disinfection is derived by determining time-kill kinetics and analysis with mathematical modelling. The link between population heterogeneity and evolvability of disinfectant tolerance was assessed by laboratory evolution experiments under periodic disinfection. The ability of disinfectant tolerant strains to evolve antibiotic resistance is assessed by serial transfer experiments with increasing concentrations of different antibiotics and by whole genome sequencing. Results: Multi-modal time-kill kinetics in three of the six disinfectants suggest the presence of disinfectant-tolerant subpopulations (i.e. persister cells). Importantly, the ability and extent to evolve population-wide tolerance under periodic disinfection is related with the presence of persister cells and the level of phenotypic heterogeneity during disinfection. Interestingly, the probability of high-level resistance evolution to certain antibiotics is attenuated in disinfectant tolerant strains as compared to the sensitive ancestor. Whole-genome sequencing reveals epistatic interactions between disinfectant tolerance and antibiotic resistance mutations, preventing access to canonical evolutionary paths to resistance. Summary: Our findings suggest that phenotypic heterogeneity can facilitate disinfection survival and the evolution of population wide tolerance, which can impact future antibiotic resistance evolution. T2 - Vereinigung Allgemeiner und Angewandter Mikrobiobiologie Jahreskongress 2023 CY - Würzburg, Germany DA - 02.06.2024 KW - Biocide KW - Resistance KW - Persistence KW - Evolution KW - Herteogeneous phenotypes PY - 2024 AN - OPUS4-60244 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nordholt, Niclas A1 - Schreiber, Frank T1 - Heterogeneous tolerance to biocides and its consequences for the evolution of antimicrobial resistance N2 - The exposure to antimicrobial substances drives the evolution of antimicrobial resistance (AMR). Biocides are antimicrobials used as disinfectants, antiseptics and preservatives. They find application on a large scale in the industrial and medical sector, but also in private households. In terms of mass, the worldwide use of biocides exceeds that of antibiotics. Thus, despite their important role in preventing the spread of pathogens, due to their ubiquity, biocides are suspected to be drivers of the antimicrobial resistance crisis. In our work we try to understand how biocides contribute to the emergence of AMR, what the underlying adaptation principles and mechanisms are and how they compare to those found for antibiotics. Here, I present results which demonstrate that phenotypic heterogeneity in E. coli, namely the formation of tolerant persister cells, can enable the survival of disinfection and consequentially facilitate the evolution of AMR. Using experimental evolution that selects for tolerance, we find that mutations in lipid A biosynthesis arise following periodic treatment with benzalkonium chloride (BAC), a widely used disinfectant. BAC tolerance is associated with additional, diverse mutations as well as changes in the susceptibility to antibiotics from different classes and changes in motility and biofilm formation, suggesting extensive regulatory re-wiring in the evolved clones. Remarkably, we find that fitness costs (growth rate reduction) incurred by BAC tolerance are alleviated in the presence of antibiotics. These findings demonstrate the complexity underlying the adaptation to antimicrobials and highlight the links between persistence to disinfectants and resistance evolution to antimicrobials. T2 - 4th VAAM discussion meeting 'Microbial Cell Biology' CY - Berlin, Germany DA - 09.10.2022 KW - Persistence KW - Biocides KW - Evolution KW - Disinfection KW - Biocide tolerance KW - Heterogeneity PY - 2022 AN - OPUS4-55958 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nordholt, Niclas A1 - Schreiber, Frank A1 - Kanaris, Orestis A1 - Schmidt, Selina T1 - Persistence against benzalkonium chloride promotes rapid evolution of tolerance under periodic disinfection N2 - Biocides used as disinfectants are important to prevent the transmission of pathogens, especially during the current antibiotic resistance crisis. This crisis is exacerbated by phenotypically tolerant persister subpopulations which can survive transient antibiotic treatment and facilitate resistance evolution. Despite the transient nature of disinfection, knowledge concerning persistence to disinfectants and its link to resistance evolution is currently lacking. Here, we show that E. coli displays persistence against a widely used disinfectant benzalkonium chloride (BAC). Periodic, persister-mediated failure of disinfection rapidly selects for BAC tolerance. BAC tolerance is associated with reduced cell surface charge and mutations in the novel tolerance locus lpxM. Moreover, the fitness cost incurred by BAC tolerance turned into a fitness benefit in the presence of antibiotics, suggesting a selective advantage of BAC-tolerant mutants in antibiotic environments. Our findings provide a mechanistic underpinning for the faithful application of disinfectants to prevent multi-drug-resistance evolution and to steward the efficacy of biocides and antibiotics. T2 - World Microbe Forum (ASM, FEMS) CY - Online meeting DA - 20.06.2021 KW - Persistence KW - Biocides KW - Evolution KW - Cross-resistance KW - Biocide tolerance PY - 2021 AN - OPUS4-53167 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Leube, Peter A1 - Vogel, Christian A1 - Simon, Franz-Georg T1 - Quantification of ultrashort per- and polyfluoroalkyl substances (PFAS) in water samples via headspace gas chromatography-mass spectrometry (GC-MS) - a method development N2 - Per- and polyfluoroalkyl substances (PFAS) were classified as a group of highly concerning chemicals over the last decades. Because of the high persistence of PFAS, their previous use led to contamination of the environment and human population. Due to ongoing use and incomplete remediation or destruction methods, the PFAS background in the environment is growing continuously. The presence of ultrashort PFAS (with ≤3 carbon atoms) in the environment is often overlooked despite their contributions to PFAS levels. These compounds may directly contaminate the environment and arise from degradation of polyfluorinated compounds as well as incomplete PFAS destruction in certain industrial processes. Nonetheless, few approaches for targeted analysis of ultrashort PFASs have been developed, except for trifluoroacetic acid (TFA). Beside liquid (LC-MS/MS), supercritical fluid (SFC-MS/MS), and ion chromatography (IC-MS)-based systems, gas chromatography coupled with mass spectrometry (GC-MS) is a promising method for detection and quantification of ultrashort PFAS. The goal of this study was to develop a simple headspace GC-MS method for the quantification of ultrashort perfluorocarboxylic acids (PFCAs) and polyfluorinated alcohols (PFOHs) in water samples. In contrast to PFOHs, functionalization of PFCAs was required for quantification. This was done by esterification with methanol at 80 °C, which can be carried out directly in the headspace GC-MS system. Moreover, several parameters were optimized to achieve a low limit of quantification (LOQ) for the analytes used: i) The ratio of the aqueous solution, methanol, and available gas phase within the analysis vessel, ii) the concentration of additional acid in esterification mixtures of PFCAs, iii) shaking frequency and iv) shaking time before analysis. After optimizing the procedure, we were able to quantify ultrashort PFCAs and PFOHs. Thus, our developed headspace GC-MS method has the potential to be used as an alternative target analysis for ultrashort-chain PFCAs and PFOHs in various water samples (groundwater, wastewater). T2 - SETAC Europe 34th Annual Meeting CY - Seville, Spain DA - 05.05.2024 KW - Ultrashort PFAS KW - Headspace GC-MS KW - Perfluorocarboxylic acid (PFCA) KW - Polyfluorinated alcohol (PFOH) PY - 2024 AN - OPUS4-60042 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vogel, Christian A1 - Roesch, Philipp A1 - Wittwer, Philipp A1 - Kalbe, Ute A1 - Simon, Franz-Georg T1 - Diffusive Gradients in Thin-films (DGT) technique as screening tool for per- and polyfluoroalkyl substances (PFAS) contamination in wastewater-based fertilizers N2 - Per- and polyfluoroalkyl substances (PFAS) are a large group of organofluorine surfactants used in the formulations of thousands of consumer goods, including aqueous film-forming foams (AFFF) used to suppress aviation fires in training scenarios, non-stick cookware, fast-food wrappers, water-repellent fabrics, medical equipment, and plastic and leather products. As a result of the perpetual use of PFAS containing products, effluents and sewage sludge from wastewater treatment plants (WWTPs) have been observed to be an important pathway for PFAS into the environment. In Germany, phosphorus and other nutrients from sewage sludge and wastewater should be recycled in WWTPs of cities with a large population. However, it is not clear if PFAS contamination from wastewater and sewage sludge end up in novel wastewater-based fertilizers. Normally, PFAS are analyzed using PFAS protocols typically with time-consuming extraction steps and LC-MS-MS quantification. However, for screening of PFAS contaminations in sewage sludge or wastewater-based fertilizers also passive sampler based on the Diffusive Gradients in Thin-films (DGT) technique can be used for the PFAS extraction. Afterwards, combustion ion chromatography (CIC) can be applied to analyse the “total” amount of PFAS on the passive sampler. Here, we show results from the DGT method in comparison to those of the extractable organic fluorine (EOF) method for a variety of wastewater-based fertilizers. Additionally, we analysed the adsorption of PFAS on the weak anion exchanger (WAX) based DGT passive sampler binding layer by infrared and fluorine K-edge X-ray adsorption near-edge structure (XANES) spectroscopy. T2 - SETAC Europe 2022 CY - Copenhagen, Denmark DA - 15.05.2022 KW - Passive sampling KW - Per- and Polyfluoroalkyl substances (PFAS) KW - Sewage sludge KW - Wastewater PY - 2022 AN - OPUS4-54883 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Simon, Franz-Georg A1 - Chubarenko, B. A1 - Purina, I. T1 - Approach for analysis of environmental impact of geosynthetics in aquatic systems by example of the Baltic Sea N2 - Whereas the behavior of geosynthetics in landfill engineering is well studied and documented since decades, little is known on application in applications such as coastal protection or ballast layers for wind energy plants. However, due to the rapid expansion of offshore wind energy, rising water levels and more extreme weather conditions as a result of climate change more and more hydraulic engineering projects will be realized in the future. Construction with geosynthetics has various advantages, but it has to be ensured that there is no negative environmental impact from the application of geosynthetics in hydraulic engineering. It is expected that any effect will be visible only on the long-term. Therefore, accelerated testing is needed to derive requirements for geosynthetics in hydraulic engineering. T2 - 7th IEEE/OES Baltic Symposium, Clean and Safe Baltic Sea and Energy Security for the Baltic countries CY - Klaipeda, Lithuania DA - 12.06.2018 KW - Geosynthetics KW - Artificial ageing KW - Micro plastic PY - 2018 AN - OPUS4-45206 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon A1 - Maierhofer, Christiane A1 - Hilgenberg, Kai A1 - Mohr, Gunther A1 - Gumenyuk, Andrey A1 - Straße, Anne A1 - Pittner, Andreas A1 - Günster, Jens A1 - Gornushkin, Igor B. A1 - Pelkner, Matthias A1 - Ehlers, Henrik A1 - Heckel, Thomas A1 - Zscherpel, Uwe A1 - Seeger, Stefan A1 - Bruno, Giovanni T1 - ProMoAM - Verfahrensentwicklung für das Prozessmonitoring in der additiven Fertigung N2 - Verfahren zum in-situ Monitoring der Prozess- und Bauteilparameter sollen Fehlstellen und Inhomogenitäten bereits während der Fertigung nachweisen und zukünftig auch die Regelung der Prozessparameter ermöglichen. T2 - Challenges in Additive Manufacturing: Innovative Materials and Quality Control, Berlin Partner Workshop CY - Berlin, Germany DA - 12.09.2018 KW - Additive Fertigung KW - Prozessmonitoring KW - ProMoAM PY - 2018 AN - OPUS4-46300 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Roesch, Philipp A1 - Wittwer, Philipp A1 - Vogel, Christian A1 - Simon, Franz-Georg T1 - Investigation of PFAS Contaminated Solid Matrices by Combustion Ion Chromatography (CIC) - Development of EOF and AOF as Sum Parameters in Environmental Analysis N2 - Per- and polyfluoralkyl surfactants (PFAS) are industrially produced surface chemicals used in daily applications that have gained public and political attention due their unnaturally high appearance in drinking water, nourishments and soils.[1] Their chemical structures exhibit both lipophilic and hydrophilic properties, leading to a highly inert and persistent character.[2] Various PFAS have shown to be bioaccumulative in plants and animals, and some have been characterized as highly toxic when ingested.[3] When exposed to the environment, PFAS slowly get mobilized by natural water resources, leading to contamination of large areas of soil and natural water sources.[4] While PFAS contamination of drinking water has been investigated intensively, perfluoralkyl contamination of soils has been rarely examined as of yet. At the same time, an increasing amount of PFAS contamination sites are being discovered worldwide, calling for a sophisticated strategy towards analytical characterization.[5] Since the number of known PFAS already exceeds 4700, the established sum parameters like extractable organic fluorine (EOF) and adsorbable organic fluorine (AOF) are key elements to fully survey the impact of exposure.[6] Simultaneously, innovative soil remediation strategies are required to contain environmental destruction and to minimize further spreading of contaminants.[7] Addressing these challenges requires suitable analytical devices that are capable of mobilizing PFAS in the solid as well as in the liquid phase. The use of combustion ion chromatography (CIC) enables analysis of both immobile and volatile PFAS and allows the detection of both total fluorine (TF) and EOF or AOF of a given soil or aqueous sample. Based on preliminary results, the clean-up of a PFAS contaminated matrix is monitored via EOF detection over time. Additionally, we tested the effectiveness of urea (CH₄N₂O) as fluoride scavenger with the aim to improve the separation of inorganic and organic fluorine and therefore, to improve AOF accuracy. The presented findings can be contributive with regard to future AOF/EOF sum parameter development and application. T2 - Eurosoil 2021 CY - Online meeting DA - 23.08.2021 KW - PFAS KW - Sum parameter analyis KW - Combustion ion chromatography PY - 2021 AN - OPUS4-53195 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vogel, Christian A1 - Kalbe, Ute A1 - Simon, Franz-Georg T1 - Leaching behavior of Antimony in MSWI bottom ash N2 - Bottom ash (BA) from municipal solid waste incineration (MSWI) contains harmful substances such as heavy metals, chloride and sulfate which are mobilized in contact with water. Standardized leaching tests are used to measure the extent of mobilization. It is known that fresh bottom ash displays elevated concentrations of various heavy metals such as lead or zinc due to the formation of hydroxo complexes as a result of high pH values of 12 and above. Storage of BA is accompanied by ageing processes, mainly the reaction of CaO and Ca(OH)2 with CO2 leading to lower pH values in contact with water around 11. Usually heavy metals concentrations are minimum at these conditions. Knowledge of the long-term leaching behavior of potentially harmful substances is crucial for the assessment of the environmental compatibility of reusing municipal solid-waste incineration bottom ash (MSWI BA) in construction, i.e., as a road base layer. BA fractions obtained from wet-processing aiming at the improvement of environmental quality were used to investigate the mobility of relevant substances. Eluates from laboratory-scaled leaching procedures (column percolation and lysimeters) were analyzed to learn about the long-term release of substances. Unsaturated conditions and artificial rainwater were used in the lysimeter tests to simulate field conditions. In addition, batch test eluates were generated at usual liquid-to-solid ratios (L/S) for compliance testing purposes. A variety of cations and anions was measured in the eluates. The wet treatment reduces the leaching of chloride and particularly sulfate by more than 60%. The release of typical contaminants for the treated MSWI BA such as the heavy metals Cu and Cr was well below 1% in the conducted leaching tests. An increase in the Sb concentration was observed in the lysimeter experiments starting at L/S 0.75 L/kg and in the column experiment at L/S 4 L/kg is assumed to be related to decreasing concentrations of Ca and thus to the dissolution of sparingly soluble calcium antimonate. The same leaching mechanism applies with V, but the concentration levels observed are less critical regarding relevant limit values. However, on the long term the behavior of Sb could be problematic for the application of MSWI BA as secondary building material. T2 - MINEA Final Conference CY - Bologna, Italy DA - 20.02.2020 KW - Antimony KW - Bottom ash KW - Leaching KW - Solubility PY - 2020 AN - OPUS4-50450 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gehrenkemper, Lennart A1 - Simon, Fabian A1 - Roesch, Philipp A1 - Fischer, Emily A1 - von der Au, Marcus A1 - Pfeifer, Jens A1 - Cossmer, Antje A1 - Wittwer, Philipp A1 - Vogel, Christian A1 - Simon, Franz-Georg A1 - Meermann, Björn T1 - Organically bound fluorine in river water - A methode comparison of CIC and HR-CS-GFMAS N2 - Abstract: Since it is unknown for many applications, which PFASs are used and how they enter the environment, target analysis-based methods reach their limits. The two most frequently used sum parameters are the adsorbable organically bound fluorine (AOF) and the extractable organically bound fluorine (EOF). Both can be quantified using either combustion ion chromatography (CIC) or high resolution-continuum source-graphite furnace molecular absorption spectrometry (HR-CS-GFMAS). Here we provide an insight on the advantageous and disadvantageous of both sum parameters and both detection methods. Our study is based on the analysis of surface water samples. Next to total fluorine (TF) analysis, AOF and EOF were determined as well as CIC and HR-CS-GFMAS are compared and results are comparatively discussed. Fluorine mass balancing revealed that, the AOF/TF proportion was higher than the EOF/TF proportion. The AOF made up 0.14–0.81% of TF and the EOF 0.04–0.28% of TF. Although, organically bound fluorine represents only a small portion of TF, PFASs are of worldwide concern, because of their extreme persistence and their bioaccumulation potential. The EOF-HR-CS-GFMAS method turned out to be more precise and sensitive than the AOF-CIC method and is a promising tool for future monitoring studies/routine analysis of PFASs in the environment. T2 - SALSA Make and Measure 2020: Advanced Characterization of Materials CY - Online meeting DA - 15.10.2020 KW - High resolution-continuum source-graphite furnace molecular absorption spectrometry (HR-CS-GFMAS) KW - Combustion ion chromatography (CIC) KW - Per- and polyfluorinated alkyl substances (PFASs) KW - Adsorbable organically bound fluorine (AOF) KW - Extractable organically bound fluorine (EOF) KW - Surfacewaters PY - 2020 AN - OPUS4-52451 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Roesch, Philipp A1 - Witter, Philipp A1 - Vogel, Christian A1 - Kalbe, Ute A1 - Simon, Franz-Georg T1 - How to investigate potential emission sources of PFAS in consumer product materials? Comparative extraction approaches and sum parameter analysis by combustion ion chromatography (CIC) N2 - Besides classical per- and polyfluorinated alkylated substances (PFAS), side-chain fluorinated polymers (SFPs) are widely applied as efficient anti-wetting and anti-greasing coatings in various daily applicated consumer products such as outdoor apparel, carpetry or paper-based food contact materials. Although the fluorinated sidechains are chemically bound to a base polymer, their release can be triggered by environmental influences or wear-off, thus contribute as significant sources of PFAS in the environment. Since only little knowledge of PFAS and SFP composition in consumer products is available, a comprehensive analytical approach might be beneficial. T2 - SETAC Konferenz 2023 CY - Dublin, Ireland DA - 30.04.2023 KW - PFAS KW - Combustion Ion Chromatography KW - Comsumer good samples PY - 2023 AN - OPUS4-57422 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Simon, Franz-Georg A1 - Frieling, Sophie T1 - Sorptionsverhalten von Antimon an Eisenoxidverbindungen N2 - Aschen und Schlacken aus der thermischen Abfallbehandlung enthalten eine Vielzahl von Schwermetallverbindungen. Für Antimon, Chrom, Kupfer, Molybdän und Vanadium werden in der neuen Ersatzbaustoffverordnung Eluatgrenzwerte für die Verwertung festgelegt. Aschen und Schlacken werden aus der Abfallverbrennungsanlage nass ausgetragen und vor einer Verwertung in der Regel mehrere Wochen gelagert. Dabei finden hydraulische Reaktionen statt und enthaltenes CaO wird zu einem Großteil in Calciumcarbonat umgewandelt. Während wässrige Eluate von frischen Aschen pH-Werte von 12 und höher aufweisen, sind die Eluate nach einigen Wochen weniger stark alkalisch. Die gemessenen Schwermetallkonzentrationen sind daher dann auch deutlich niedriger, mit Ausnahme von Antimon (Sb) und Vanadium (V). Hier steigen die Konzentration mit der Lagerungsdauer. Grund sind sinkende Konzentrationen von Ca-Ionen, die sonst zu einer Ausfällung von Antimonaten und Vanadaten führen. Zu hohe Eluatwerte von Sb und V können durch Sorption an Eisenoxidverbindungen gemindert werden. Als besonders wirkungsvoll hat sich Schwertmannit (Eisen-Oxyhydroxysulfat) erwiesen. Es entsteht durch Oxidation von pyrithaltigem Material durch Mikroorganismen und wird deshalb in Gebieten gefunden, in denen Braunkohle abgebaut wurde, z.B. in der Lausitz. Weitere untersuchte Eisenoxidverbindungen waren Hämatit und Schlämme aus der Abtrennung von Eisen und Mangan in Wasserwerken. T2 - 5. Internationales Bergbausymposium WISSYM 2023 CY - Dresden, Germany DA - 25.09.2023 KW - Rostasche KW - Sorption KW - Ersatzbaustoffe PY - 2023 AN - OPUS4-58702 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Leube, Peter A1 - Vogel, Christian A1 - Simon, Franz-Georg T1 - Quantification of ultrashort per- and polyfluoroalkyl substances (PFAS) in water samples via headspace gas chromatographymass spectrometry (GC-MS) - a method development N2 - Ultrashort PFAS (≤ 3 carbon atoms) were overlooked for a long time in analytical monitoring. Beside through the use of these substances, they contribute to the PFAS background in the environment through (environmental/ bio-) degradation and incomplete destruction3 of PFAS with longer carbon chains or other fluorinated compounds. As part of the German-Israeli Cooperation in Water Technology Research project „Detection, quantification, and treatment of per- and polyfluoroalkyl substances in groundwater“ (DEFEAT-PFAS), we are developing an as simple as possible direct headspace (HS-)GC-MS method to detect trifluoroacetic acid (TFA) and perfluoropropanioc acid (PFPrA), as well as trifluoroethanol (TFEtOH), pentafluoropropanol(PFPrOH) and hexafluoroiospropanol (HFIP) in water samples. Here we present the results of the PFAS mentioned in spiked ultrapure water solutions. T2 - German Israeli Water Technology Status Seminar CY - Koblenz, Germany DA - 18.06.2024 KW - Ground water KW - Per- and Polyfluoroalkyl substances (PFAS) KW - Gas chromatography - mass spectrometry (GC-MS) PY - 2024 AN - OPUS4-60330 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Roesch, Philipp A1 - Wittwer, Philipp A1 - Simon, Franz-Georg T1 - Detailed Investigation of Perfluoroalkyl Surfactant Contaminated Soil Samples by Combustion Ion Chromatography - Development of EOF and AOF as Reference Values in Environmental Analysis N2 - Per- and polyfluoralkyl surfactants (PFASs) are industrially produced surface chemicals used in daily applications that have gained public and political attention due their unnaturally high appearance in drinking water, nourishments and soils. Their chemical structures exhibit both lipophilic and hydrophilic properties, leading to a highly inert and persistent character. Various PFASs have shown to be bioaccumulative in plants and animals, and some have been characterized as highly toxic when ingested. When exposed to the environment, PFASs slowly get mobilized by natural water resources, leading to contamination of large areas of soil and natural water sources. While PFASs contamination of drinking water has been investigated intensively, perfluoralkyl contamination of soils has been rarely examined as of yet. At the same time, an increasing amount of PFASs contamination sites are being discovered worldwide, calling for a sophisticated strategy towards analytical characterization. Since the number of known PFASs already exceeds 4700, the established sum parameters like extractable organic fluorine (EOF) and adsorbable organic fluorine (AOF) are key elements to fully survey the impact of exposure. Simultaneously, innovative soil remediation strategies are required to contain environmental destruction and to minimize further spreading of contaminants. Addressing these challenges requires suitable analytical devices that are capable of mobilizing PFASs in the solid as well as in the liquid phase. The use of combustion ion chromatography (CIC) enables analysis of both immobile and volatile PFASs and allows the detection of both total fluorine (TF) and EOF or AOF of a given soil or aqueous sample. Based on preliminary results, the clean-up of a PFAS contaminated solid matrix is monitored via EOF detection over time. Additionally, we demonstrate the pH dependency of hydrogen fluoride absorption on active carbon (AC) and found a simple organic additive to be an effective fluoride scavenger. The presented findings can be contributive with regard to future AOF/EOF sum parameter development and application. T2 - DECHEMA Symposium Strategien zur Boden- und Grundwassersanierung 2020 CY - Online meeting DA - 23.11.2020 KW - PFAS KW - SPE extraction KW - Combustion ion chromatography KW - Organo fluorine analysis KW - Soil extraction KW - Sewage extraction PY - 2020 AN - OPUS4-51978 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -