TY - CONF A1 - Strzelczyk, Rebecca 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 - Bonnerot, Olivier T1 - XRF Ink analysis of selected fragments from the Herculaneum collection N2 - Hundreds of papyrus rolls, carbonized during the 79CE eruption of Mount Vesuvius, were discovered in 1754 at Herculaneum. Sophisticated mechanical methods for unrolling the best-preserved scrolls have been applied, with varying success. However, such processes have been abandoned, to prevent risk from irremediable damage or loss and to preserve the integrity of the extremely fragile rolls. Following the development of X-ray based non-invasive techniques, attempts to virtually unroll the scrolls were made. The most common ink in Antiquity was carbon-based, and the main element of carbonized papyrus is carbon, making these investigations difficult. However, some attempts with synchrotron X-ray phase-contrast tomography (XPCT) were successful. Recently, the identification of antique inks containing metals raised hope that if some of the inks contain metal the rolls can be virtually unrolled using conventional CT- technique. We investigated the inks of a selection of partially unrolled fragments stored at the Biblioteca Nazionale di Napoli with X-ray fluorescence in order to select the best candidates for tomography. Despite the many difficulties (analysis of several layers sticking together, letters barely visible, difficulty to separate contribution from the ink and from the papyrus, inhomogeneity of the support, fragility of the fragments…), encouraging results were found, with a number of inks from Greek fragments found to contain additions to the soot (Fe, Pb, Cu P). T2 - International Symposium on Archaeometry CY - Online meeting DA - 16.05.2022 KW - XRF KW - Ink KW - Herculaneum KW - Papyrus PY - 2022 AN - OPUS4-54892 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 - Horn, Wolfgang T1 - VOC-Sampling inside display cases with focus on BEMMA evaluation N2 - Museum display cases aim to protect art and cultural goods not only from theft and vandalism, but also from dirt and dust. An often-heard argument within a call for tender of new display cases is that there should be no emission inside of the display case. This is nearly impossible for new ones especially when they must also fulfill the requirement of an air change rate of less than 0.1 per day. For example, constructions or decorations in exhibition spaces, storage containers in depot rooms, and exhibition display cases release volatile substances that might lead to irreversible changes or, under certain circumstances, damage to the stored or displayed objects. In Germany beneath the well-established Oddy-test also the BEMMA procedure is used to evaluate the construction materials. For larger amounts of display cases control measurements of VOCs at the end of construction or buildup is quite common. However, what is necessary to measure the air inside of display cases. What are the circumstances when the display cases were closed before the test period? Is it possible to organize a clean environment for reliable measurements. How comparable are the resulting VOCs with results from BEMMA test and control measurement at the end. The BEMMA procedure should include a further VOC-test at 60 °C. What are the benefits of this enlargement. Mainly materials that have a high potential to store VOCs inside of the material in combination with a less permeable surface should be evaluated stricter than others. T2 - IAQ 2024 The International Conference on Indoor Air Quality in Heritage and Historic Environments CY - New York, USA DA - 18.11.2024 KW - Emission KW - Air quality KW - Display cases KW - VOC PY - 2024 AN - OPUS4-61967 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Catanzaro, Ilaria 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 - Prajapati, Harshit Kumar T1 - Transmission mediated adaptation of virulence in Deformed Wing Virus N2 - The emergence of several infectious diseases in the last few decades has resulted in elevated honeybee (Apis mellifera) colony losses. Especially, (+) single-stranded RNA viruses like Deformed Wing Virus (DWV) have become prominent due to a novel vector from Asia, the ectoparasitic mite – Varroa destructor. The evolution of DWV may have been significantly affected by the establishment of a new transmission route, as represented by V. destructor. According to virulence-transmission trade-off theory, viruses found in vector-invaded hosts may evolve a level of virulence that maximizes transmission and subsequent spread in the colony. In this study, we tested this prediction by passaging DWV in white-eyed pupae by microinjection over 10 generations, to emulate the vectoring function of V. destructor, while subjecting the virus to 3 different transmission selection regimes: (i) Early: at 4 days, (ii) Optimal: at 6 days, and (iii) Late: at 8 days post-injection. The evolved viral genomes are analyzed by long-read (Oxford Nanopore) sequencing. The reconstructed viral population dynamics are compared with the inter-host transmission and viral load, to identify fixed mutations contributing to the adapted virulence. Using a site-/gene-specific test of natural selection, we explore the phenotypic effects of virulence among the evolved viruses. T2 - International Virus Bioinformatics Meeting 2024 CY - Leuven, Belgium DA - 28.05.2024 KW - Evolution KW - Varroa destructor KW - Honeybees KW - Virus PY - 2024 AN - OPUS4-61719 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Even, Morgane 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 - Erdmann, Eileen T1 - Tools for Knufia petricola: new techniques for CRISPR/Cas9-based genome editing N2 - Black microcolonial fungi represent a group of ascomycetes with similar adaptations for existing in natural and anthropogenically created extreme habitats. They exhibit slow yeast-like or meristematic growth, do not form specialized reproduction structures and accumulate the black pigment 1,8-dihydroxynaphthalene (DHN) in the multilayered cell walls. We chose the rock inhabitant Knufia petricola of the Chaetothyriales as a representative for developing methods for genetic manipulation, simulation of mineral weathering and study of symbiotic interactions. Here, we report on the expansion of the genetic toolkit by more efficient multiplex CRISPR/Cas9 using a plasmid-based system for expression of Cas9 and multiple sgRNAs and three additional resistance selection markers. The targeted integration of expression constructs by replacement of essential genes for pigment synthesis allows for an additional color screening of the transformants. The black-pink screening due to the elimination of pks1 (melanin) was applied for promoter studies using GFP fluorescence as reporter, while the black-white screening due to the concurrent elimination of pks1 (melanin) and phs1 (carotenoids) was used to identify transformants that contain the two expression constructs for co-localization or bimolecular fluorescence complementation (BiFC) studies. In addition, two intergenic regions (igr1, igr2) were identified in which expression constructs can be inserted without causing obvious phenotypes. Plasmids of the pNXR-XXX series (Schumacher, 2012) and new compatible entry plasmids were used for fast and easy generation of expression constructs and are suitable for use in other fungal systems as well. T2 - 31st Fungal Genetics Conference CY - USA, CA, Pacific Grove DA - 15.03.2022 KW - Microcolonial fungi KW - Genetic engineering KW - Fluorescent proteins PY - 2022 AN - OPUS4-54586 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sobisch, Lydia-Yasmin 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 - Sobisch, Lydia-Yasmin 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 - Röllig, Mathias T1 - Thermografie zur Vergleichbarkeit von Emissionsmessung im 3D-Druck N2 - Die Bedeutung der Extrudertemperatur bei kleinen Desktop 3D Druckern der Fused Filament Fabrication (FFF) Technologie auf die Emission von ultrafeinen Partikeln im Druckbetrieb ist nicht zu unterschätzen. Allerdings zeigen kommerzielle 3D Drucker häufig eine systematische Temperaturabweichung zum Sollwert, d.h. die eingestellte Temperatur weicht von der tatsächlichen Temperatur ab. Da die Partikelemission meist temperaturabhängig ist, ist eine genaue Messung der tatsächlichen Extrudertemperatur für den Vergleich von Emissionsdaten aus unterschiedlichen Druckermodellen relevant. T2 - DGZfP Jahrestagung 2025 CY - Berin, Germany DA - 26.05.2025 KW - Thermografie KW - Fused Filament Fabrication (FFF) KW - Ultrafeine Partikel KW - Extrudertemperatur KW - Temperaturmessung PY - 2025 AN - OPUS4-63328 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Piehl, Patrick T1 - Thermochemical Treatment of Steel Work Dusts and Sludges for the Recovery of Zinc and Iron N2 - Steel work dusts and sludges usually contain severe amounts of zinc, lead, cadmium, and other heavy metals, which hinder direct recycling and make these materials potentially hazardous for the environment. To tackle this issue, here, two thermochemical treatment methods for the reductive workup of blast furnace sludge, electric arc furnace dust, and comparable steelwork dusts are presented. In the first method, carbon contained blast furnace sludge is employed as reducing agent for the material’s metal oxides. By this, heavy metals get evaporated and a metallic iron containing residue that may be reused in electric arc furnace steelmaking is formed. Additionally, the use of hydrogen for reducing iron and heavy metal oxides in steelwork dusts is presented. Here, high evaporation rates of heavy metals can be reached, and sponge iron is formed. Investigations using thermogravimetry and equilibrium simulations provide insides into the reactions taking place. For both processes an upscaling to pilot scale is ongoing. T2 - EUROSLAG 2024 CY - Bilbao, Spain DA - 23.10.2024 KW - Electric arc furnace dust KW - Blast furnace sludge KW - Recycling KW - Ressource recovery KW - Zinc PY - 2024 AN - OPUS4-61499 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Blotevogel, J. T1 - Thermal PFAS Destruction in a Full-Scale Hazardous Waste Incinerator N2 - Incineration is currently the only commercial full-scale technology available to destroy per- and polyfluoroalkyl substances (PFAS) in large solid and liquid waste streams. Given previous experience of dioxin formation during halogenated waste incineration, concerns about the emission of products of incomplete destruction (PIDs) from PFAS incineration exist. The overarching objective of this project is to track the fate of fluorine during full-scale hazardous waste incineration in order to demonstrate the readiness, viability, and level of safety for thermal PFAS destruction in various waste streams. The specific objectives of this project are (1) to enhance our understanding of key variables and conditions on PFAS incineration performance, (2) to identify major PIDs under insufficient treatment conditions, (3) to explore the catalytic role of fly ash and other process-relevant surfaces in thermal PFAS decomposition, and (4) to determine the potential formation of polyfluorinated dibenzodioxins and dibenzofurans. T2 - 2025 SERDP & ESTCP PFAS Project Meeting CY - Long Beach, CA, USA DA - 04.08.2025 KW - PFAS KW - Hazardous waste incineration PY - 2025 AN - OPUS4-64189 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nitsche, Sarah T1 - The role of the stress-activated MAP kinase SAK1 in Knufia petricola N2 - Mitogen-activated protein (MAP) kinases are highly conserved in animals, plants, and fungi and represent fundamental parts of signaling networks in eukaryotic cells. Black DHN (1,8-dihydroxynaphthalene) melanin and orange carotenoids are produced by many fungi in specific cell types/under certain conditions for protecting cells from abiotic and/or biotic stresses. Microcolonial black fungi constitutively produce DHN melanin, contain the conserved carotenogenic gene cluster, exhibit slow yeast-like growth and survive in extreme environments. Thus, the question arises to which extent pigment formation and responses mediated by the stress-activated MAP kinase module contribute to the observed extremotolerance. We address this question in the rock inhabitant Knufia petricola, the only representative of the extremotolerant black fungi that is genetically amendable. Here, the mutations of pks1, phs1 and both genes result in melanin-free (pink), carotenoid-free (black) and pigment-free (white) strains, respectively (Voigt Knabe et al. 2020, Sci Rep). The gene encoding the stress-activated MAP kinase was deleted in the wild-type and different pigment-deficient backgrounds. In addition, strains were generated that express a GFP-SAK1 fusion protein from the sak1 locus to follow the cytosolic/nuclear shuttling of SAK1 upon stress. Growth of the obtained single, double and triple deletion mutants was tested by dropping cell suspensions on solid media supplemented with different stress-inducing agents. The Δsak1 mutants show slightly reduced growth rates even under non-stress conditions and are hypersensitive to different stress conditions: reduced growth is observed on media inducing, for instance, osmotic, oxidative, membrane, and pH stress, and upon incubation at 30 °C (heat stress). Melanin-free Δsak1 mutants are more sensitive than black Δsak1 mutants to some but not all stress conditions, suggesting that melanin and the SAK1 pathway have complementary roles in protecting K. petricola from stress. T2 - VAAM Fachgruppentragung "Molecular Biology of Fungi" CY - Kaiserslautern, Germany DA - 07.09.2022 KW - Fungus KW - Extremotolerance KW - Signal transduction PY - 2022 AN - OPUS4-55677 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Martens, Birte T1 - The evolution of symbiont and immune system interactions in Blattodea N2 - Immunity plays an important role in evolutionary ecology. The immune system interacts with both pathogens, which can act as important selective forces, and symbionts, which are regulated by the host‘s immune system and can also play a role in the host‘s immune defenses. The Blattodea consist of what is commonly known as cockroaches and the termites, who are themselves specialized eusocial cockroaches. Blattodea have two symbiont types that are characteristic to either the cockroaches or the termites (Table 1). These symbiont transitions open up the opportunity to characterize and investigate host-symbiont-pathogen interactions and how they evolved in Blattodea. T2 - Ecological Immunology Workshop 2025 CY - Joachimsthal, Germany DA - 15.09.2025 KW - Evolution KW - Cockroaches KW - Immunity KW - Symbionts KW - Host-Symbiont-Interactions PY - 2025 AN - OPUS4-64971 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Martens, Birte T1 - The evolution of symbiont and immune system interactions in Blattodea N2 - Immunity plays an important role in evolutionary ecology. The immune system interacts with both pathogens, which can act as important selective forces, and symbionts, which are regulated by the host‘s immune system and also can play a role in the host‘s immune defenses. The Blattodea consist of what is commonly known as cockroaches and the termites, who are themselves specialized eusocial cockroaches. Blattodea have two symbiont types that are characteristic to either the cockroaches or the termites (Table 1). These symbiont transitions open up the opportunity to characterize and investigate host-symbiont-pathogen interactions and how they evolved in Blattodea. T2 - Insect Infect Meeting 2025 CY - Berlin, Germany DA - 07.04.2025 KW - Evolution KW - Cockroaches KW - Immunity KW - Symbionts KW - Host-Symbiont-Interactions PY - 2025 AN - OPUS4-64970 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Taghavi Kalajahi, Sara T1 - The effectiveness of cathodic protection (CP) on microbiologically influenced corrosion (MIC) control N2 - Cathodic protection (CP) is an electrochemical method, to manage corrosion in different industries, especially in buried and sub-merged environments. In those environments microorganisms are present and can affect the corrosion process and cause microbiologically influenced corrosion (MIC). Most of the industry standards recommend performing CP using -800 mV (Ag/AgCl), however, if microorganisms capable of initiating MIC are present, for instance sulfate reducing bacteria (SRB), it is recommended to use even more negative potentials. It is assumed that this will provide adequate protection of the metal. Currently there is no information or valid data in the context of CP, on the level of MIC threat and the extent to which more negative potentials can be used to provide adequate protection and not over-protection (due to hydrogen embrittlement threat). Conflicting statements can be found in the literature regarding the effectiveness of CP on MIC, from reducing biofilm attachment to increasing bacterial activity and biofilm attachment. Recently, the development and lower price of molecular microbiological methods (MMM) have opened the door for more effective studies of MIC mechanisms along with other electrochemical methods and surface analysis. In this work, the genetic functionality of biofilms formed in the laboratory under CP conditions is investigated using transcriptomics. Gene expression of SRB biofilms under different CP potentials (-800, -850 and -900 mV) will be studied; comparison with control will allow us to distinguish the specific genes that are differentially expressed, leading to a better understanding of the mechanism of CP to affect bacterial activity and diversity. Keywords - cathodic protection, microbiologically influenced corrosion, molecular microbial methods. T2 - IBBS CY - Berlin, Germany DA - 09.09.2024 KW - Microbiologically influenced corrosion PY - 2024 AN - OPUS4-61981 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nordholt, Niclas 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 - Koerdt, Andrea T1 - Technical challenges for the investigation of Microbiologically influenced corrosion under laboratory conditions across several sectors N2 - Microbiologically influenced corrosion MIC occurs in different sectors, under various conditions and can significantly contribute to material degradation. The most convincing effect can be observed with sulphate-reducing bacteria (SRB). There are many stakeholders who do not need to be convinced of this as there is ample scientific evidence clearly showing that SRBs corrode metal. However, many believe this is solely due to the produced H2S. Fewer people are aware that SRBs also have other mechanisms that can lead to corrosion, such as electrical MIC on metal (direct electron uptake from the metal used as electron donor). Despite this, many sectors or industries remain skeptical in several areas. When considering other classes or species, the skepticism increases even more. The reason is simple: microbiologist cannot consistently prove MIC on laboratory scale for all corrosive microorganisms. In contrast to materials sciences, where experiments can be narrowed down to a limited number of parameters, microbiology is too complex to simulate simply in the lab. Several factors are mandatory for the growth of microorganisms, consequently increasing the number of parameters. Even when making the system more complex, there are still unknown species in the field, whose growth conditions are not yet understood. We know via 16S rRNA analysis that the species is present, but that is all we know. If these samples are enriched in the lab, many species will not survive and their impact on the whole community cannot be investigated. Therefore, lab tests related to MIC works only for a certain number of microorganisms. This means the key-result for other disciplines are missing, and important numbers for calculating the lifespan of a material can only be provided with limited accuracy. This is neither satisfying nor useful for engineers, material scientist or similar professionals, and it is understandable. However, MIC occurs, and we need to address it in our infrastructure or other important areas. With this presentation, I aim to show the currently available techniques for testing on a laboratory scale. I will use SRBs and methanogenic archaea as examples to highlight the advantages and disadvantages of each method and point out where improvements are needed. The examples will be cross-sectoral and applicable to other sectors as well. This talk will highlight the currently existing challenges of testing MIC in the laboratory and may help generate creative solutions. T2 - MICxUS 2025 CY - Nicosia, Cyprus DA - 21.01.2025 KW - MIC KW - Biocorrosion KW - Laboratory testing KW - Interdisziplinarity KW - Microorganisms PY - 2025 UR - https://www.unic.ac.cy/ehresearch/micxus2025/#tab-98dc74f32bf3b8f95bd AN - OPUS4-63725 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Tang, Chi-Long T1 - Sub-4 nm particles from FFF-3D printing measured with the TSI 1 nm CPC and the Airmodus A11 nCNC N2 - Concerns have been raised as Fused Filament Fabrication (FFF) desktop 3D printer emits harmful ultrafine particles (dP < 100 nm) during operation in indoor spaces. However, the vast majority of previous emission studies have neglected the possible occurrence of sub-4 nm particles by using conventional condensation particle counter (CPC) for detection. Thus, the total particle emission could be systematically underestimated. This study has compared two diethylene glycol (DEG) based instruments to evaluate their suitability for measuring organic FFF particles in the sub-4 nm size range either as particle counter or as a particle size spectrometer. T2 - European Aerosol Conference 2024 CY - Tampere, Finland DA - 25.08.2024 KW - Air pollution KW - Emission testing KW - FFF-3D printing KW - Sub-4nm particles KW - Ultrafine particles PY - 2024 AN - OPUS4-60930 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Simon, Franz-Georg 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 - Koerdt, Andrea T1 - Simulating Microbiologically Influenced Corrosion (MIC) at Seabed Environment in Monopile N2 - Ensuring the safety of offshore wind structures (OWS) is critical to guaranteeing their long-term performance and supporting reliable green energy supply. Microbiologically influenced corrosion (MIC) presents a significant challenge, particularly for monopiles in seabed environments. This study investigates the behavior of microorganisms and their impact on the corrosion process of carbon steel within monopiles. To simulate MIC at the sediment/water interface, an in-house experimental column was developed and inoculated with sediment and water samples from the North Sea. The system was operated under varying flow rates to replicate seabed movement conditions. Multiple molecular microbiological methods, surface analysis techniques, and other approaches were employed to assess the effects of different treatments. This study provides insights into MIC mechanisms in offshore environments and supports the development of strategies to monitor MIC in OWS infrastructure T2 - ISMOS10 CY - Nashville, TN, USA DA - 11.08.2025 KW - MIC KW - Environmental Simulation KW - Field testing KW - Marine Environment PY - 2025 AN - OPUS4-64298 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna T1 - Seasonal microplastic concentrations along the rivers Rhine and Danube N2 - Over the last 20 years, many researchers, politicians and citizens have become increasingly aware of the growing plastic problem of our time. A lack of recycling concepts and plastic collection points as well as careless dumping lead to accumulation of plastic products in the environment. Natural weathering can cause these plastics to degrade and fractionate, meaning that microplastics (1 1,000 µm, ISO/TR 21960:2020) and nanoplastics (< 1 µm, ISO/TR 21960:2020) of various synthetic polymer materials can now be detected in all parts of the world. Whether microplastics or nanoplastics pose a toxicological hazard is being investigated in a variety of ways. Valid results are still pending. However, the EU precautionary principle applies to micro- and nanoplastics. Monitoring of microplastics is already required in the revision of the Drinking Water and Wastewater Framework Directive. Reliable monitoring of rivers can be carried out by sampling with sedimentation boxes and microplastic detection by using thermal extraction desorption gas chromatography/mass spectrometry (TED-GC/MS) in routine operation (Figure 1). The river Rhine was sampled for microplastic masses at three different sampling locations over a period of one year and in addition the Danube at randomized sampling locations The TED-GC/MS results showed that various synthetic polymers frequently produced in industry, such as polyethylene, polypropylene or polystyrene as well as the tire compound styrene-butadiene rubber were found. The work not only shows a possible workflow for monitoring concepts, but also provides information on environmentally relevant concentrations of microplastics and tire components in surface waters. This in turn is necessary for ecotoxicological studies. T2 - ESOPS CY - Berlin, Germany DA - 09.09.2024 KW - Microplastics KW - TED-GC/MS KW - Polymer 3R PY - 2024 AN - OPUS4-61016 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Davenport, Rebecca T1 - Regulations versus practice and the Divine Name: Ink analysis in medieval Torah scrolls N2 - The medieval Rabbis had very strict rules for the construction of a Sefer Torah. The Divine Names should be written • by a qualified scribe • who is ritually pure • in the presence of a minyan (10 adult Jewish men) • in an appropriate frame of mind • without being interrupted However, when these scrolls were written it would have been impossible to verify any of this after the fact. While we do not currently have any way to determine how recently the scribes had bathed, or what they might have been thinking as they wrote, we can now know much more about the inscription of the Divine Name than these scribes ever would have guessed. It is sometimes apparent from a visual inspection of the text that the Divine Name has been written in a second stage, from irregular letter kerning or a different ink colour. Using XRF, we have been able to discover more instances of a different ink used for the Name, and have shown that in some cases the secondary ink was also used to correct the main text, suggesting that the later writing was done by a master scribe who also proofread the entire scroll. Using a Brucker M6 Jetstream, it has been possible to produce elemental “heat maps” of whole paragraphs or even large sections of a parchment sheet. Using such large samples of text, we can usefully compare the levels of copper and zinc used to write individual letters or words despite their relatively low concentration, which permits very fine differentiation of the inks used. The techniques presented here would also be highly applicable to assessing ink degradation, as they are able to detect much smaller differences in ink composition than had previously been possible. T2 - The International Iron Gall Ink Meeting 2025 CY - Lisboa, Portugal DA - 07.05.2025 KW - XRF spectroscopy KW - Torah scrolls KW - Jewish studies KW - XRF mapping PY - 2025 AN - OPUS4-65036 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Leube, Peter 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 - Leube, Peter 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 - Schuehle, Florian T1 - Quality assured uptake rates for passive sampling of indoor air VOCs N2 - Generation of experimental uptake rates (UR) for > 70 VOCs (7d /100 μg m-3) Application in German Environmental Survey – VOC exposure assessment Assurance of transparency concerning UR generation and uncertainty creates basis for decision making and comparability of measurement results. Exemplarily the uncertainty u(UR) of toluene UR was modelled and determined statistically with own laboratory data (relative standard deviation of actively sampled test gas atmosphere – RSDa and n = 5 exposed passive samplers – RSDp) in line with EN 838 as well as from variation of literature UR – RSD UR,lit. T2 - Airmon 2022, 10th International Symposium on modern principles of air monitoring and biomonitoring CY - Bristol, UK DA - 06.11.2022 KW - IAQ KW - VOC KW - Diffusive sampling KW - Uptake rate PY - 2022 AN - OPUS4-56583 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Misra, Archismita T1 - Polyoxometalate Ionic Liquids as Protective Coatings for Industrial Infrastructure and Cultural Heritage against Microbiologically Influenced Corrosion (MIC) N2 - Corrosion of stone and metal due to acid rain and biodeterioration poses significant challenges for industrial and residential infrastructure, as well as cultural heritage, including statues and historical artefacts. A promising mitigation strategy involves thin, transparent films of polyoxometalate-based ionic liquids (POM-ILs) as chemical shields. Stone samples coated with acid-resistant, biocidal POM-ILs exhibited negligible corrosion when exposed to simulated acid rain, in stark contrast to the severe deterioration of unprotected samples. Additionally, their biocidal properties effectively prevent biofilm formation on coated surfaces. Following studies successfully explored the effectiveness of the coating against lampenflora growing in the Pommery Champagne cellar; and the long-term performance of POM-ILs under outdoor environmental conditions. So, POM-ILs have already demonstrated remarkable anticorrosion and antimicrobial properties against aerobic microorganisms and, being water-insoluble, do not leach into aquatic ecosystem. The current research project repurposes the POM-ILs, extending their application to metals, specifically targeting microbiologically influenced corrosion (MIC) in cultural heritage artefacts made of brass, carbon steel, cast iron, and bronze. This involves optimizing nanocoating adhesion to the metal surface and evaluating its protective efficacy against MIC caused by anaerobic microorganisms such as methanogenic archaea and sulfate reducing bacteria (SRB). This presentation will highlight POM-ILs as sustainable, high-performance nanocoatings for biocorrosion mitigation. It will showcase published success stories, discuss ongoing research and proof-of-concept results, and explore future prospects for these advanced materials in safeguarding metal infrastructure and artefacts across different industrial sectors as well as in the context of cultural heritage conservation. T2 - 10th International symposium on applied microbiology and molecular biology in oil systems (ISMOS10) CY - Nashville, Tennessee, USA DA - 11.08.2025 KW - Polyoxometalates KW - Corrosion KW - Microbiologically Influenced Corrosion KW - Ionic Liquid PY - 2025 AN - OPUS4-64548 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Misra, Archismita T1 - Polyoxometalate Ionic Liquids as Protective Coatings for Industrial Infrastructure and Cultural Heritage against Microbiologically Influenced Corrosion (MIC) N2 - Corrosion of stone and metal due to acid rain and biodeterioration poses significant challenges for industrial and residential infrastructure, as well as cultural heritage, including statues and historical artefacts. A promising mitigation strategy involves thin, transparent films of polyoxometalate-based ionic liquids (POM-ILs) as chemical shields. Stone samples coated with acid-resistant, biocidal POM-ILs exhibited negligible corrosion when exposed to simulated acid rain, in stark contrast to the severe deterioration of unprotected samples. Additionally, their biocidal properties effectively prevent biofilm formation on coated surfaces. Following studies successfully explored the effectiveness of the coating against lampenflora growing in the Pommery Champagne cellar; and the long-term performance of POM-ILs under outdoor environmental conditions. So, POM-ILs have already demonstrated remarkable anticorrosion and antimicrobial properties against aerobic microorganisms and, being water-insoluble, do not leach into aquatic ecosystem. The current research project repurposes the POM-ILs, extending their application to metals, specifically targeting microbiologically influenced corrosion (MIC) in cultural heritage artefacts made of brass, carbon steel, cast iron, and bronze. This involves optimizing nanocoating adhesion to the metal surface and evaluating its protective efficacy against MIC caused by anaerobic microorganisms such as methanogenic archaea and sulfate reducing bacteria (SRB). This presentation will highlight POM-ILs as sustainable, high-performance nanocoatings for biocorrosion mitigation. It will showcase published success stories, discuss ongoing research and proof-of-concept results, and explore future prospects for these advanced materials in safeguarding metal infrastructure and artefacts across different industrial sectors as well as in the context of cultural heritage conservation. T2 - Euro-MIC COST Action - Closing Workshop Conference CY - Horsens, Denmark DA - 17.09.2025 KW - Polyoxometalates KW - Corrosion KW - Microbiologically Influenced Corrosion KW - Ionic Liquid PY - 2025 AN - OPUS4-64549 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. 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 - 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 - Taghavi Kalajahi, Sara T1 - Pilot Study of a Laboratory- Based Microbiologically Influenced Corrosion (MIC) Test Using Microbiological Consortia Sampled from the Field N2 - Experts widely agree that the verification of microbiologically influenced corrosion (MIC) require the use of multiple lines of evidence (MLOE), including metallurgical, microbiological, operational/historical and environmental/chemical aspects. Existing standards related to MIC, such as NACE TM0106, TMO212 and TM0194, primarily aim to offer guidance on gathering such evidence. Working Group 5 of Euro-MIC COST action 20130 (Achieving standardization) proposed a laboratory-based approach that directly confirms the capability of the sampled consortium of microorganisms, obtained from the specific field location under investigation, to increase and/or alter the corrosion processes. It is necessary to verify this laboratory approach by conducting it in different laboratories, performed by different scientist. In the current study, the experiments based on the laboratory protocol of WG5 were conducted at Endures’s laboratory using environmental samples (sediment and seawater) from the North Sea. Metal coupons (carbon steel C1010) were exposed to sediment and seawater samples with varying microbial inoculums and controls over 150 days. Microbial identification, corrosion product analysis, and surface morphology assessments were conducted using molecular and microscopy techniques. The results indicate distinct microbial influences, particularly in treatments containing yeast, which fostered heightened anaerobic activity, notably by sulfate-reducing bacteria (SRB). Weight loss measurements and surface analysis revealed elevated corrosion rates and susceptibility to pitting corrosion in microbial inoculum treatments, with yeast presence exacerbating corrosion processes. Elemental analysis confirmed the presence of iron sulfide in corrosion byproducts, affirming SRB activity. The findings emphasize the importance of employing a MLOE approach and investigating pitting corrosion to better understand the impact of microorganisms on metal corrosion in the marine environments. This study contributes to advancing knowledge in the field and developing standardization: the lab-to-field transition for MIC testing. T2 - MIC-STANDS CY - Lisbon, Portugal DA - 24.07.2024 KW - Microbiologically influenced corrosion (MIC), Multiple lines of evidence (MLOE) KW - Marine Corrosion KW - Achieving standardization PY - 2024 AN - OPUS4-61979 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schreiber, Frank 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 - Schreiber, Frank 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 - Schreiber, Frank 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 - Nordholt, Niclas 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 - Schreiber, Frank A1 - Nordholt, Niclas 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 - Vogel, Christian T1 - Per- and polyfluoroalkyl substances (PFAS) in ski waxes and snow from cross-country skiing in Germany - Comparative study of target analysis and sum parameters N2 - Per- and polyfluoroalkyl substances (PFAS) can enter the environment in different ways. Possible sources are PFAS containing consumer products. One common product that makes use of the material properties of PFAS is ski wax. Here, the PFAS ensure less frictional resistance, thus allows for increased speed. However, people who wax their ski with these waxes could absorb PFAS in their body, which can lead to health problems in the long term. Moreover, PFAS applied in ski wax abrade onto snow during use, which contaminates the environment. In our study, we analyzed various currently available ski waxes (2020s) and ski waxes from the 1980s with PFAS target analysis and with the sum parameters extractable organically bound fluorine (EOF), hydrolysable organically bound fluorine (HOF) and total fluorine (TF). Moreover, snow samples from the long-distance cross-country ski trail “Kammloipe” in the Ore mountains in Germany where sampled and analyzed with PFAS target analysis and the adsorbable organically bound fluorine (AOF) sum parameter to document the entry of PFAS from ski waxes into the environment. In opposite to the ski waxes from the 1980s much more ski waxes from the 2020s contain high (total) fluorine values. The highly fluorinated ski waxes contain up to approx. 6% of fluorine. The EOF and HOF sum parameters of the ski waxes are strongly decreased in comparison to the TF values (max. approx. 1000 mg/kg = 0.1%). But even the PFAS-free labeled ski waxes have EOF/HOF values in the low mg/kg range. In the snow samples from different spots of the ski trail, both the AOF sum parameter and the PFAS target analysis identified PFAS. Moreover, on a PFAS hotspot also soil samples were analyzed, which indicate that PFAS from the ski waxes adsorb after snow melting into the soil. Thus, our results show that the use of ski waxes is a possible contribution to the environmental contamination of PFAS, which is hopefully drastically reduced with the ban on fluorinated waxes by the International Ski and Snowboard Federation (FIS). T2 - SETAC Europe CY - Vienna, Austria DA - 11.05.2025 KW - Per- and polyfluoroalkyl substances (PFAS) KW - Contaminated Soil KW - Ski wax PY - 2025 AN - OPUS4-63096 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gehrenkemper, Lennart 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 - Brandt, S. 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 - Nordholt, Niclas T1 - NBD-DDA: a tool to study biocide & disinfectant resistance mechanisms N2 - Quaternary ammonium compounds (QACs) are widely used as active agents in disinfectants, antiseptics, and preservatives. Despite being in use since the 1940s, there remain multiple open questions regarding their detailed mode-of-action and the mechanisms that can make bacteria less susceptible to QACs, including phenotypic heterogeneity. Goals To develop a fluorescent quaternary ammonium compound and to use it to investigate the mechanisms underlying QAC susceptibility in bacteria. Material & Methods A fluorescent quaternary ammonium compound, N-dodecyl-N,N-dimethyl-[2-[(4-nitro-2,1,3-benzoxadiazol-7-yl)amino]ethyl] azanium-iodide (NBD-DDA), was synthesized. Chemical structure and purity of NBD-DDA was confirmed by mass spectrometry and NMR spectroscopy. Antimicrobial activity against S. aureus, P. aeruginosa and E. coli was assessed by determination of minimum inhibitory concentrations and time-kill assays. Uptake, heterogeneity and efflux of NBD-DDA in wild-type and efflux-deficient mutants (ΔtolC) were determined, using flow cytometry and fluorometry. Sub-cellular localization of NBD-DDA was determined using confocal laser scanning microscopy. Results NBD-DDA was readily detected by flow cytometry and fluorescence microscopy with standard GFP/FITC-settings. NBD-DDA retained antimicrobial activity comparable to the structurally similar, widely used QAC benzalkonium chloride (BAC). Characteristic time-kill kinetics and increased tolerance of a BAC tolerant E. coli strain against NBD-DDA suggest that the mode of action of NBD-DDA is similar to that of BAC. NBD-DDA was preferentially localized to the cell envelope, which is a primary target of BAC and other QACs. Leveraging NBD-DDA‘s fluorescent properties, it was demonstrated that reduced cellular accumulation underlies BAC tolerance in a BAC tolerant E. coli strain and that NBD-DDA is subject to efflux mediated by TolC. Summary Overall, NBD-DDA’s antimicrobial activity, its fluorescent properties, and its ease of detection render it a powerful tool to study mechanisms of QAC susceptibility and mode-of-action in bacteria, both on the level of populations and single-cells. T2 - VAAM - Jahrestagung 2024 CY - Würzburg, Germany DA - 02.06.2024 KW - Biocides KW - Phenotypic heterogeneity PY - 2024 AN - OPUS4-61177 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Julseth, Mara Jean T1 - Multivalent Myteries: How Termite Chromosome Chains Shape Evolution N2 - Termites challenge long-standing assumptions about insect social evolution. One important difference compared to the social ants, bees and wasps lies in their chromosomes: termites are diploid, with X/Y sex differentiation observed in most species and males playing active roles across all castes and life stages. Adding to their uniqueness, termites exhibit multivalent chromosome chains during male meiosis—an intriguing and seldom seen feature of eukaryote evolution. These chains, in addition to other chromosomal formations, such as bivalent rings and rods, may serve to suppress recombination, thereby mitigating against the potentially harmful effects of inbreeding. Again, this positions termites as an important contrasting study system to other social insect groups, where recombination rates tend to be elevated. Multivalent chromosome chains may also play a significant role in speciation processes by increasing the likelihood of chromosomal translocations and promoting genomic islands of divergence. In European Reticulitermes, variability in chain length and stability both between and within species provides a compelling model system for studying the evolutionary importance of multivalent chromosome chains at intra- and interspecific levels and at different evolutionary time scales. To investigate these dynamics, we collected over 200 colonies of Reticulitermes species across the Mediterranean, generating de novo reference genomes, comprehensive population genomic as well as karyotypic data from three recently diverged species. Our findings shed light on the intricate relationship between chromosomal architecture and evolutionary mechanisms in termites, offering new insight into how genome structure shapes species evolution. T2 - ESEB 2025 Congress CY - Barcelona, Spain DA - 17.08.2025 KW - Termites KW - Chromosome evolution PY - 2025 AN - OPUS4-65059 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fuentes, Elsa A1 - Prieto, Beatriz A1 - Gorbushina, Anna T1 - Mixed model biofilm: interactions between algae, fungi and cyanobacteria and their effects on granite biodeterioration N2 - Granite, despite being one of the most widely used rocks for building material cultural heritage, is also one of the least studied. Previous works have shown that environmental parameters modulated by climate change will lead to changes in the microbial composition of biofilms grown on stone, but also to changes in the production of EPS, in the composition of pigments and, as a consequence, in the biodeterioration processes that this rock undergoes (Fuentes, 2023). Considering that the colonisation process is highly dynamic, small changes in climatic conditions can lead to the formation of different types of biofilms and diverse interactions between species. Knowing the contribution of the different organisms to the deterioration process is important both to anticipate the consequences that climate change will have on the deterioration of the granite, but also when addressing the processes of recolonization after cleaning, to ensure an improvement of the present situation. So, in order to continue my line of research on granite biodeterioration, the aim of this new project is to study the contribution of each type of organism (green algae, cyanobacteria and fungi) to the process of granite deterioration as well as the specific effect on each mineral, in addition to its role in the resilience and response of biofilms to environmental changes. With this main objective, the effect of the type of substrate on the composition of a model mixed biofilm formed by the fungus Knufia petricola, the algae Jaagichlorella sp. and the cyanobacterium Synechocystis sp. will be studied. The results obtained on granite will be compared with those obtained with other lithic types such as marble or limestone. Furthermore, it will be observed if the different ratios between organisms lead to changes in the capacity of these organisms to generate biodeterioration and to buffer climatic changes. Finally, the susceptibility of each mineral that makes up the granite - quartz, feldspars, micas - to biodeterioration mediated by each type of organism will be analysed. To address these questions, on the one hand, the response of the mixed biofilms as a whole will be evaluated by means of confocal microscopy, PAM, as well as the quantification of pigments and EPS, and on the other hand, the effect of these organisms on the deterioration of the substrates, through the use of SEM and TEM, which will allow the assessment of both the changes in porosity and the appearance of deterioration in the surface layers of the rock. This research will deepen the knowledge of the processes of granite deterioration, which have been limitedly studied in relation to microorganisms; but also aims to provide the scientific community with a model mixed biofilm to increase the reproducibility between experiments, one of the main limitations of this field of study. T2 - 19th International Biodeterioration and Biodegradation Symposium CY - Berlin, Germany DA - 09.09.2024 KW - Biofilm KW - Stone KW - Algae KW - Fungi KW - Cyanobacteria KW - Cultural heritage PY - 2024 AN - OPUS4-62272 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Klein, Luise T1 - Miniaturization Options in VOC Emissions Assessments of Consumer Products: Comparison of Test Chambers and Dynamic Headspace Extraction Systems N2 - Different emission testing devices were compared to measure reliable initial indoor air concen-trations of volatile organic compounds (VOC) emitting from consumer products. Compared to conventional medium- or large-scale test chambers, smaller devices including micro chambers and dynamic headspace extraction systems offer options for increased sample throughput, automation as well as reduced costs, which could facilitate their application in routine analysis of consumer product-related VOC emissions. T2 - Indoor Air 2024 CY - Honolulu, Hawaii, USA DA - 07.07.2024 KW - VOC KW - Emissions KW - Consumer product KW - Indoor air PY - 2024 AN - OPUS4-62098 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braymer, Joseph T1 - Methanobacterium IM1 as a model organism to study MIC N2 - Microbiologically influenced corrosion (MIC), also known as biocorrosion, is a process where microbes corrode metal surfaces causing detrimental damage to manmade infrastructure. Several studies, mainly under anaerobic conditions, have identified sulfate-reducing bacteria and methanogens as key players in biocorrosion. However, an important issue is that most MIC-related microbes at the moment are non-culturable. In addition, improved technologies (i.e., omics, biochemical, and microscopy methods) are needed to study, detect, simulate, and modulate MIC-related cases. Therefore, the selection of strains that can cause MIC, are culturable, and are genetically accessible, are of high importance for establishing new methods to study MIC on the molecular level. For example, the archaeal strain Methanobacterium IM1 has caught great attention due to its involvement in biocorrosion processes. Genes encoding for a novel enzyme (MIC NiFe-hydrogenase) have been proposed in this methanogen to be directly related to the e T2 - International Biodeterioration and Biodegradation Symposium 19 CY - Berlin, Germany DA - 11.09.2024 KW - Biocorrosion KW - Methanogen KW - Iron KW - Hydrogenase KW - Mechanism PY - 2024 AN - OPUS4-61508 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Frelih, Milena T1 - Material-Microbiome Interactions N2 - Estimations show that the anthropogenic mass, the technosphere, already exceeds the biomass on Earth. Understanding the technosphere-environment interactions and their impacts is key to safe and healthy ecosystems and human societies. At BAM, we aim at promoting awareness for microorganisms living and evolving in contact with human-made materials and technical systems. We are creating datasets of biofilms on plastic and other anthropogenic materials and in the context of important technical challenges (e.g. microbially influenced corrosion or biocide-induced antimicrobial resistance). This enables us to identify and examine key organisms in the investigated systems that potentially harbor new, also industrially relevant, species and traits. Further, we explore material effects on aquatic microbial communities, aiming at the development and establishment of innovative and environmentally relevant methodologies. By using bioinformatic and molecular tools and interdisciplinary research, we enhance the understanding of material-microbiome interactions for a safe and sustainable future. T2 - NFDI4Microbiota Annual Conference CY - Cologne, Germany DA - 30.09.2025 KW - Microbiome KW - Microplastics KW - Black fungi KW - Nanoparticles PY - 2025 AN - OPUS4-64637 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Horn, Wolfgang A1 - Müller, Birgit T1 - Low-odour and low-emission indoor products - Nose vers. odour threshold values N2 - To achieve good air quality in buildings, it is necessary to remove, avoid or reduce cleaning loads through ventilation. To reduce the cleaning loads and their effect on the odour perception of the occupants, a sensory test in indoor spaces and on building products is necessary in addition to VOC emission measurements of the contaminants. ISO 16000-28 provides the basis for odour assessment of products using a human olfactory panel. Through many years of experience and testing of these methods, it can now be assumed that reproducible odour ratings are available for many products used indoors. An odour measurement is mandatory for the Blue Angel for carpets and is being tested for environmentally friendly resilient floor coverings. Based on the results of an earlier project and new results of the upcoming study, the ISO should be revised and completed. The project investigates the odour and VOC emissions of building products based on natural raw materials. The data generated is used to address several issues, which are briefly explained below. Floor coverings based on linoleum and rubber are included in the Blue Angel eco-label with an odour assessment. The aim of the project is to clarify whether other assessment methods in addition to intensity can provide better information. Positive hedonics have an influence on the intensity assessment. Typically, building products show high intensity with low hedonic values. Results for wood-based products often show high intensity and positive hedonics. Based on these examples, an appropriate odour assessment of wood-based products for the Blue Angel, supported by research results, should be possible. The concept of the odour guide value which is based on odour threshold values was renewed in 2023. This approach will now be compared with the standardised odour measurement (16000-28). This assessment is based on GC/MS measurements and uses odour thresholds analytically when panel-based odour assessment is not possible. For this procedure well defined odour thresholds are necessary T2 - AIRMON 2025 The 11th International Symposium on Modern Principles of Air Monitoring and Biomonitoring. CY - Loen, Norway DA - 15.06.2025 KW - Emission KW - Indoor air quality KW - Materials emissions test KW - VOC KW - Geruch PY - 2025 UR - https://stami.no/en/wp-content/uploads/sites/2/2025/06/Programhefte-Airmon-2025-Juni-10-YTH.pdf AN - OPUS4-63634 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vogel, Christian 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 - Gerrits, Ruben T1 - Iron uptake by the rock-inhabiting fungus Knufia petricola N2 - Iron is arguably the most essential metal in living organisms. For rock-inhabiting fungi its acquisition might be unconventional as they (1) tend to inhabit iron-deficient, oxygen-rich surfaces like marble monuments and solar panels and (2) produce the black, iron-adsorbing pigment melanin. We used a range of analytical methods, ongoing mineral dissolution experiments and gene deletion mutants of the model rock-inhabiting fungus Knufia petricola to figure out the mechanisms and substrate deteriorating effects of iron uptake by these organisms. To study both siderophore-mediated and reductive iron assimilation (RIA), genes like sidC, encoding a putative siderophore synthetase and ftr1 and fet3 encoding the subunits of an iron permease-oxidase were deleted. At iron deficient conditions, growth of the wild type (WT) and ΔsidC mutant was similar, whereas growth of the Δftr1-fet3 mutant and the double mutant ΔsidC/Δftr1-fet3 was diminished and absent, respectively. We were not able to detect the siderophore of K. petricola and the WT and mutants were not able to grow at low concentrations of strong iron chelators. However, in a cross-feeding experiment, an overexpression strain of sidC allowed more growth of ΔsidC/Δftr1-fet3 on iron deficient medium than the WT, whereas the ΔsidC mutant could not do so at all. Compared to the WT, the sidC overexpression strain also withstood oxidative stress better and had a shorter lag time and higher growth rate. Combined, these results indicate that K. petricola relies more on RIA than siderophore-mediated uptake as it likely excretes low quantities of a primarily intracellular siderophore. Interestingly, Δftr1-fet3 had a higher iron content than the WT at iron deficient conditions. This difference disappeared upon deletion of melanin synthesis (Δpks1 vs. Δpks1/Δftr1-fet3): melanin-bound iron can likely not be used without RIA. K. petricola’s chelation incapacity implies a habitat free of competition for iron while offering us a mitigation strategy. T2 - ECFG16 CY - Innsbruck, Austria DA - 05.03.2023 KW - Siderophore KW - Melanin KW - Reductive iron assimilation PY - 2023 AN - OPUS4-57148 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -