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 -