TY - CONF A1 - Bonse, Jörn A1 - Schwibbert, Karin T1 - Laserstrukturierte Oberflächen: Ein Weg zur Kontrolle der Biofilmbildung? N2 - Bakterielle Biofilme stellen in medizinischen und industriellen Bereichen ein ernsthaftes Problem dar. Eine der größten gesellschaftlichen Herausforderungen liegt in der zunehmenden Resistenz von Bakterien gegen Biozide, die bei antimikrobiellen Behandlungen eingesetzt werden, z.B. durch übermäßigen Einsatz in Medizin, Industrie und Landwirtschaft oder durch Reinigung und Desinfektion in Privathaushalten. Daher sind neue effiziente bakterienabweisende Strategien, die den Einsatz von Bioziden vermeiden, dringend erforderlich. Ein vielversprechender Weg zur Erzielung bakterienabweisender Oberflächen liegt in der berührungslosen und aseptischen großflächigen Laserbearbeitung von technischen Oberflächen. Maßgeschneiderte Oberflächentexturen, ermöglicht durch verschiedene Laserbearbeitungsstrategien, die zu topographischen Skalen im Bereich von Nanometern bis Mikrometern führen, können eine Lösung für diese Herausforderung darstellen. In dem Vortrag wird ein Überblick über den aktuellen Stand der Technik bei der subtraktiven Texturierung von Laseroberflächen zur Kontrolle der Biofilmbildung bei verschiedenen Bakterienstämmen und in unterschiedlichen Umgebungen gegeben. Auf der Grundlage spezifischer Eigenschaften von Bakterien und laserbearbeiteten Oberflächen werden die Herausforderungen antimikrobieller Oberflächendesigns erörtert und zukünftige Richtungen aufgezeigt. T2 - GRAVOSeminar, GRAVOmer Kompetenznetzwerk CY - Online meeting DA - 28.02.2024 KW - Laser-Materialbearbeitung KW - Ultrakurzpuls-Laser KW - Biofilme KW - Antibakterielle Oberflächen KW - Oberflächenfunktionalisierung PY - 2024 UR - https://gravomer.de/veranstaltungen-anzeigen/laserstrukturierte-oberflaechen-ein-weg-zur-kontrolle-der-biofilmbildung AN - OPUS4-59594 LA - deu 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 - JOUR A1 - de Araujo Abilio, André A1 - Wolodko, John D. A1 - Eckert, Richard B. A1 - Skovhus, Torben L. T1 - Development of an expert system for assessing failures in oil and gas pipelines due to microbiologically influenced corrosion (MIC) N2 - This study highlights the modeling of an expert system for the classification of internal microbiologically influenced corrosion (MIC) failures related to pipelines in the upstream oil and gas industry. The model is based on artificial neural networks (ANNs) and involves the participation of 15 MIC experts. Each expert evaluated a number of model case studies ranging from MIC- to non-MIC-driven upstream pipeline failures. The model accounts for variations in microbiological testing methods, microbiological sample types, and degradation morphology, among other variables. It also accounts for missing datasets, which is commonly the case in actual failure assessments. The outcome is an expert system model whose outputs are classes (classification ANN) which comprises MIC potential and data confidence. The performances of two approaches are contrasted in this study. One classifies the output in 5 classes, a 5-output classification (5OC) model; the other in 3 classes, a 3-output classification (3OC) model. The 5OC model had an accuracy of 62.0% while the simpler 3OC model had a better accuracy of 74.8%. This modelling exercise has demonstrated that knowledge from experts can be captured in a reasonably effective model to screen for possible MIC failures. It is hoped that this study not only may contribute to a better understanding of the prevalence of MIC in the oil and gas sector, but also may highlight the key areas necessary to improve the diagnosis of MIC failures in the future. KW - Corrosion engineering KW - Oil and gas pipelines KW - Carbon steel KW - Artificial neural networks (ANNs) KW - Failure analysis KW - Microbiologically influenced corrosion (MIC) KW - Expert systems PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-632084 DO - https://doi.org/10.1016/j.engfailanal.2024.108426 SN - 1350-6307 VL - 163 SP - 1 EP - 16 PB - Elsevier Ltd. AN - OPUS4-63208 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Deland, Eric T1 - Environmental conditions affect the corrosion product composition of Methanogen induced microbiologically influenced corrosion (Mi-MIC) N2 - Corrosion is a very expensive and serious problem in the different industry sectors, eg. Petroleum-, On- and off-shore, infrastructure. It is estimated that 20% of all corrosion damage is caused by microorganisms or microbiologically influenced corrosion (MIC). Several microorganisms are known to cause corrosion, including sulfate-reducing bacteria, nitrate-reducing bacteria, methanogens etc. For several years, methanogens were regarded as a mild corroder (~0.065 mm/yr), largely due to a lack of detailed investigation on the corrosion mechanism under real-environment simulated conditions. Resulting in the common belief that siderite, a non-conductive compound, is the sole corrosion product (CP) of methanogen-induced MIC (Mi-MIC). To simulate natural environmental conditions, we developed and introduced the multiport flow column system (MFC), a multi-sectional corrosion flow-cell. Using the MFC, we obtained ten times higher corrosion rates than previously reported. With a combination of several analytical techniques, such as ToF-SIMS, SEM-EDS and FIB-SEM, we found strong indication that siderite is not the sole corrosion product of Mi-MIC. The corrosion layers contained phosphorus, oxygen, magnesium, calcium and iron. The differences in the CP between static and dynamic environments demonstrated the impact of testing procedures on the corrosive potential of methanogens. To further verify and deepen our understanding of Mi-MIC, we are currently studying the influence of additional environmental parameters (e.g. pH, salinity, flow rate) on Mi-MIC. Overall, results of this study will expand the current understanding of MIC from both analytical and mechanistic points of view, thus aiding the development of different mitigation strategies for various industry sectors. T2 - ISMOS-8 CY - Online meeting DA - 08.06.2021 KW - Methanogen-induced microbiologically influenced corrosion KW - Carbon steel KW - ToF-SIMS KW - Modelling studies PY - 2021 AN - OPUS4-54041 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Deland, Eric T1 - Environmental conditions impact the corrosion layer composition of Methanogen induced microbiologically influenced corrosion (Mi-MIC) N2 - Microbiologically influenced corrosion (MIC) is a now well-known challenge and affects industry, society and infrastructure. For a long time, the impact of methanogen-induced MIC (Mi-MIC) was underestimated. This was mainly due to the rather low published corrosion rates and the presumed corrosion product siderite, which is not electrically conductive. In our laboratory, we were able to show that this trivialization or underestimation of Mi-MIC was due to the nature of the testing. The static systems used so far do not provide environmentally relevant information about the corrosion rate and the corrosion product, especially for methanogens To further illustrate the importance of the environment on the MIC process, we established a multiport flow column (MFC), to simulate the natural environment. With this method, and in contrast to published results using the static conditions, we obtained ten times higher corrosion rates. We analyzed the corrosion products with a combination of techniques, like ToF-SIMS, SEM-EDS and FIB-SEM, and found strong evidence that siderite is not the sole corrosion product of Mi-MIC. The corrosion layers contain phosphorus, oxygen, magnesium, calcium and iron and lacked on carbon-related species. It is hypothesized that methanogens may have influenced the nucleation process of siderite, converting bicarbonate into carbon dioxide for methanogenesis. This results in increased localized corrosion and reduced siderite formation. To verify and deepen our understanding of Mi-MIC, we are currently studying the influence of additional environmental parameters (e.g. pH, salinity, flow rate etc.) on Mi-MIC and the subsequent impacts on corrosion rates and the corrosion products. Overall, results of this study will expand the current understanding of MIC from both analytical and mechanistic points of view, thus aiding the development of different mitigation strategies for various industry sectors. T2 - Eurocorr 2021 CY - Online meeting DA - 20.09.2021 KW - Methanogen-induced microbiologically influenced corrosion KW - Carbon steel KW - SEM-EDS KW - Modelling studies PY - 2021 AN - OPUS4-54043 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Deland, Eric A1 - Kleinbub, Sherin T1 - Is Methanogen-induced microbiologically influenced corrosion (Mi-MIC) underestimated? N2 - The role of methanogens in microbiologically influenced corrosion (Mi-MIC) is often neglected, due to 1) low reported corrosion rates and 2) the suspected corrosion product siderite, which is electrically non-conductive. Typically, MIC corrosion studies are carried out using batch cultures, which did not represent the dynamic conditions, i.e. pipeline and provide insufficient information on the overall corrosion potential. We established a unique approach, a multiport flow column (MFC), to simulate pipeline conditions and obtained 10-times higher corrosion rates than previously published. Our result showed that testing procedures have a large impact on the corrosive potential of methanogens. We found strong indications with a combination of ToF-SIMS, SEM-EDS and FIB-SEM analyses that siderite is not the sole corrosion product. The corrosion layers contain phosphorus, oxygen, magnesium, calcium and iron. To verify and deepen our understanding of Mi-MIC, we are currently studying the influence of other environmental parameters (e.g. pH) on Mi-MIC. T2 - VAAM 2021 CY - Online meeting DA - 18.03.2021 KW - Methanogen-induced microbiologically influenced corrosion KW - Carbon steel KW - MIC Island PY - 2021 AN - OPUS4-54042 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dinter, Adelina-Elisa ED - Dinter, Adelina-Elisa T1 - Development of a MIC single archaea-ICP-ToF-MS-method for analysis of various elements in solid steel samples N2 - With the latest ICP-MS technology - ICP-ToF (time of flight)-MS - it is possible to analyze the multi-element fingerprint of individual cells. The interface between material and environmental analysis thus receives special attention, e.g. when considering corrosion processes. Microbiologically influenced corrosion (MIC) is highly unpredictable due to the diversity of microbial communities involved. The development of the MIC-specific ICP-ToF-MS analytical method presented here at the single cell level, in combination with the investigation of steel-MIC interactions, contributes significantly to progress in instrumental MIC analysis and will enable clarification of the processes taking place. The supplied document shows the basis of a four minutes lightning talk. T2 - EuroMIC 2021 CY - Online meeting DA - 22.06.2021 KW - SC-ICP-ToF-MS KW - Single cell analysis KW - Microbiologically influenced corrosion KW - Lightning talk PY - 2021 AN - OPUS4-52905 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dinter, Adelina-Elisa T1 - Development of a single cell-ICP-ToF-MS-method for multielement analysis of MIC organisms grown on solid steel samples N2 - The latest ICP-MS technology - ICP-ToF (time of flight)-MS – enables the analysis of the multi-element fingerprint of individual cells. The interface between material and environmental analysis thus receives special attention, e.g., when considering corrosion processes. Microbiologically influenced corrosion (MIC) is a highly unpredictable phenomenon due to the influence of the environment, microbial communities involved and the respective electron source. However, the interaction pathway between cells and the metal surface remains unclear. The development of the MIC-specific ICP-ToF-MS analytical method presented here at the single cell level, in combination with the investigation of steel-MIC interactions, contributes significantly to progress in instrumental MIC analysis and will enable clarification of the processes taking place. For this, a MIC-specific staining procedure was developed. It allows the analysis of archaea at a single cell level and provides information about the interaction of the cells with the staining agent which is extremely scarce compared to other well characterized organisms. Additionally, the single cell ICP-ToF-MS is used for the analysis of archaea involved in MIC of steel. Hence, the possible uptake of individual elements from different steel samples is investigated - the information obtained will be used in the future to elucidate underlying mechanisms and develop possible material protection concepts, thus combining modern methods of analytical sciences with materials. T2 - DAAS Doktorandenseminar 2021 CY - Online meeting DA - 20.09.2021 KW - Sc-ICP-ToF-MS KW - Single cell analysis KW - Microbiologically influenced corrosion KW - Archaea PY - 2021 AN - OPUS4-53340 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dinter, Adelina-Elisa T1 - Development of a MIC single archaea-ICP-ToF-MS-method for analysis of various elements in solid steel samples N2 - ICP-ToF (Flugzeitanalysator, engl. time of flight)-MS ermöglicht den Multielement Fingerabdruck einzelner Zellen (single cell) zu analysieren. Die single cell-ICP-ToF-MS kommt bei dem vorgestellten Poster bei der Analyse von Archaeen, die an mikrobiell beeinflusster Korrosion (engl. microbiologically influenced corrosion, MIC) von Stahl eine Rolle spielen, zum Einsatz. Mittels sc-ICP-ToF-MS wird die mögliche Aufnahme von einzelnen Elementen aus dem jeweiligen Stahl untersucht – die erhaltenen Informationen fließen zukünftig in die Aufklärung zugrunde liegender Mechanismen sowie Entwicklung möglicher Materialschutzkonzepte ein. Die Arbeiten Verknüpfen moderne Methoden der Analytical Sciences mit Materialien. T2 - Tag der Chemie 2021 CY - Online meeting DA - 06.07.2021 KW - SC-ICP-ToF-MS KW - Single cell analysis KW - Microbiologically influenced corrosion KW - Archaea PY - 2021 AN - OPUS4-52941 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dinter, Adelina-Elisa T1 - Examination of biological samples by means of single-cell ICP-ToF-MS N2 - Up to now, different analytical methods for single cell analysis exist focusing on key features such as size, shape, morphology and elemental composition. The combination of the latest ICP-MS techniques - ICP-ToF-MS - together with the latest developments in the field of sample delivery - micro droplet generator (MDG) – will allow a Deep insight into the composition and size of cells. Microbiologically influenced corrosion (MIC) is an oxidation of metals affected by the presence or activity (or both) of microorganisms e.g. Shewanella Putrefaciens in biofilms on the surface of the corroding material. As this can happen for example in the soil on iron pipes of water pipes, in oil tanks or on steel sheet piling, there is great interest in MIC research, not only from various industrial sectors, but also from the environmental aspect. T2 - SALSA - Make & Measure CY - Online Meeting DA - 15.10.2020 KW - SC-ICP-ToF-MS KW - Single cell analysis KW - MDG ICP-ToF-MS KW - Microdroplet generator PY - 2020 AN - OPUS4-52441 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dinter, Adelina-Elisa T1 - Deciphering corrosion processes of MIC organisms - single cell-ICP-ToF-MS analysis of archaea on solid steels N2 - ICP-ToF (time of flight) MS enables the analysis of the multi-element fingerprint of single cells. The single cell ICP-ToF-MS is used in the presented poster for the analysis of archaea involved in microbiologically influenced corrosion (MIC) of steel. By means of sc-ICP-ToF-MS, the possible uptake of individual elements from the respective steel is investigated - the information obtained will be used in the future to elucidate underlying mechanisms and develop possible material protection concepts. The work combines modern methods of analytical sciences with materials. T2 - SALSA - Make & Measure 2021 CY - Online meeting DA - 16.09.2021 KW - Sc-ICP-ToF-MS KW - Single cell analysis KW - Microbiologically influenced corrosion KW - Archaea KW - Poster presentation PY - 2021 AN - OPUS4-53337 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - European Food Safety Authority (EFSA), A1 - European Centre for Disease Prevention and Control (ECDC), A1 - European Chemicals Agency (ECHA), A1 - European Environment Agency (EEA), A1 - European Medicines Agency (EMA), A1 - European Commission's Joint Research Centre (JRC), T1 - Annex to: Scientific report 'Impact of the use of azole fungicides, other than as human medicines, on the development of azole-resistant Aspergillus spp.' doi:10.2903/j.efsa.2025.9200 - Annex E - Detailed answer to Term of Reference 5 'Environmental hotspots' and Term of Reference 6 'Prevention and control options' N2 - The widespread use of azole compounds in various sectors has led to the emergence of azole-resistant Aspergillus fumigatus (ARAf), which poses a significant challenge for treating fungal infections, especially in immunocompromised patients. Certain environmental conditions and practices, particularly in agricultural settings and the use of azoles as biocides, have been identified as hotspots for the selection and dispersal of azole-resistant strains of Aspergillus spp. Factors contributing to the selection of resistance include the use of azoles in crop protection, wood preservation and, to a much lesser extent, veterinary medicine. For plant protection products (PPPs), a number of scenarios (green waste of indoor-grown vegetables, uses with the production of wet pomace used as fertiliser, maize or sugar beet silage, and field heaps including flower bulbs) are deemed high risk for hotspot development. Based on EU authorised use patterns, these scenarios are characterised by the hazard characteristics of the azole fungicides in terms of activity against the wild-type Aspergillus spp. compared to resistant strains, substrate characteristics and residue levels, and environmental conditions that promote the growth of the fungus. For biocidal azole applications, products (biocidal product [BP]) for temporary preservation of freshly cut wood have been identified to have the potential for hotspot formation because freshly cut wood allows the growth of Aspergillus spp., and azole concentrations in treated wood are above the predicted no effect concentration (PNEC) for resistance selection (PNECres) and below the minimum inhibitory concentration (MIC) of ARAf for most analysed products on the EU market. Following identification of environmental hotspots, the report recommends measures to prevent the selection of azole-resistant strains in the environment, including controlled storage of organic waste, proper waste management, and responsible use and disposal of azole-treated products. Azole use in veterinary medicinal products (VMPs) represents a very small percentage of total azole use and is unlikely to be a significant source of selection of resistance in the environment. As such, the focus for mitigating resistance should be on other uses of azoles. The report stresses the importance of ongoing surveillance to monitor the presence of ARAf in the environment and to inform risk assessments and management strategies. As industrial chemicals, the azole substances are mostly used as intermediates (precursors) to manufacture yet a different substance, are formulated into a mixture or are reported to be manufactured as active substances in PPP, BP or VMP (therefore already covered above). There are only a few industrial azole substances with widespread use, and as for the moment, there is no evidence from the literature that industrial azoles would be a source of a possible hotspot; thus, the industrial chemicals were not further investigated. There are several areas where further research is needed, including understanding the environmental conditions that support the growth of Aspergillus spp. in different agricultural matrices or on wood, assessing human exposure to resistant strains, regional waste practices and the impact of active substance combinations for azole resistance selection. There is also a need for more comprehensive data on the use and quantities of azole-containing products. Furthermore, industrial substances with widespread use and having antifungal effects, e.g. an antidandruff substance in cosmetics, could be further investigated. Measures were identified that could be implemented with respect to the use of azole fungicides in PPPs as well as in BPs and with respect to the storage, processing and disposal of crop (waste) materials containing azole residues to prevent or minimise the selection of environmental resistance or to minimise the spread of resistant Aspergillus spp. to patients. Any measures that slow down or prevent growth in the presence of azoles, sporulation and dispersal of Aspergillus spp. should be encouraged. A coordinated effort among various stakeholders, including farmers, manufacturers, industrial users, waste managers, regulatory bodies and scientists, is essential to effectively address the challenge of azole resistance in A. fumigatus. KW - Antimicrobial surfaces KW - Biocides KW - Antimicrobial resistance KW - Azoles KW - Fungi KW - Wood preservatives PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-652187 UR - https://doi.org/10.5281/zenodo.14223436 DO - https://doi.org/10.5281/zenodo.14223435 SP - 1 EP - 76 PB - Zenodo CY - Geneva AN - OPUS4-65218 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geburtig, Anja A1 - Gorbushina, Anna A1 - Plarre, Rüdiger A1 - Stephan, Ina T1 - Umweltsimulation an der BAM – Grundlegende Ansätze mit Beispielen aus der natürlichen Umwelt N2 - Drei grundlegend verschiedene Ansätze für Umweltsimulation werden an Beispielen illustriert: (i) Ganzheitlicher Ansatz - Nachstellen von Umweltmilieus im Labor Ziel ist hier das Nachstellen von (kombinierten) Umweltbedingungen im Labor; die Umweltparameter werden mit all ihren Wechselwirkungen aufgebracht. Hauptnutzen ist eine gegenüber der natürlichen Beanspruchung erhöhte Reproduzierbarkeit der Umweltbedingungen. Hat man sein Laborsetup entwickelt, ist es auf verschiedene Materialien anwendbar. Unter solchen Laborbedingungen ermittelte Lebensdauern sind dabei nicht auf die typischerweise sehr variablen Real-Umweltbedingungen übertragbar. (ii) Parametrisierter Ansatz - Ermittlung einzelner Materialempfindlichkeiten Hierbei werden im Labor die Wirkungen separater Umweltparameter auf Materialien nachgestellt. Für eine solche Separation der Einflussfaktoren ist insbesondere die Aufschlüsselung möglicher Wechselwirkungen der Umwelt-parameter (z.B. Mikroklima an bestrahlten Oberflächen) erforderlich. Einzelne (meist Alterungs-) Empfindlichkeiten können qualitativ nachgewiesen werden oder sogar – als Beanspruchungs-Wirkungs-Funktionen – quantifiziert werden, was einen wesentlichen Schritt in Richtung der Digitalisierung der Material¬prüfung darstellt. Insbesondere ist dann auch eine Lebensdauer-vorhersage für vorgegebene Zeitreihen der Beanspruchungs¬parameter umsetzbar. (iii) Rückwirkungen auf die Umwelt Umweltbeanspruchungen können zur Freisetzung von Schadstoffen in die Umwelt führen. Durch die Nachstellung kritischer, aber realitätsnaher Einsatzszenarien kann die Menge an freigesetzten Substanzen abgeschätzt werden. Egal, welcher Ansatz verfolgt wird – ein Vergleich mit der oder einer Real-beanspruchung ist unerlässlich, ebenso wie die Messdatenaufzeichnung (data logging) aller potenziell relevanten Beanspruchungsparameter während dieser Realbeanspruchung. Obwohl die naturnahe Umwelt – sowohl in der BAM als auch bei der GUS – gegenüber der technischen Umwelt eher untergeordnet auftritt, werden zur Illustration Beispiele aus der naturnahen Umwelt verwendet. T2 - 50. Jahrestagung der GUS CY - Online meeting DA - 23.03.2022 KW - Umweltsimulation PY - 2022 SN - 978-3-9818507-7-2 SP - 79 EP - 89 AN - OPUS4-55015 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaut, Valerie T1 - Antibiotic tolerance of biofilms emerging from multicellular effects of antibiotic efflux N2 - Biofilms are multicellular assemblies of bacteria living in a self-produced extracellular matrix. One characteristic of biofilms is that they are difficult to kill. Different mechanisms, like the development of persister cells or efflux pumps which pump some antimicrobials out of the cell, make them tolerant. Our central hypothesis is that efflux pump activity causes emergent antimicrobial tolerance of multicellular bacterial populations, through the interplay of efflux-mediated spatial interactions and efflux-linked persistence. To verify the hypothesis, we combine computational modelling with information gained from 3 types of multicellular assemblies. We are currently generating strains that differ in their levels of efflux activity, mixes are then cultivated together in the 3 model systems. In colonies the link between structure and spatial patterns of gene expression will be characterized. Using a microfluidic device, the interactions range of efflux as a response to different antimicrobials will be determined. In a flow chamber a 3D biofilm will be generated, to investigate the biofilm development over time and persister cell formation. All results will be compared with model predictions. T2 - EuroBioFilms2024 CY - Copenhagen, Denmark DA - 25.06.2024 KW - Antibiotic KW - Biofilm KW - Tolerance KW - Efflux PY - 2024 AN - OPUS4-61277 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaut, Valerie T1 - Antibiotic tolerance of biofilms emerging from multicellular effects of antibiotic efflux N2 - Efflux pumps play an important role in the context of antimicrobial resistance, which is the ability to grow in the presence of antimicrobials. Many of these transporters can be categorized into multidrug efflux pumps, extruding various antimicrobials out of the cells, and thereby leading to antimicrobial resistance. It has been shown that efflux pumps can be linked by global regulators that regulate efflux pump expression affecting cell-to-cell-interactions, membrane integrity and biofilm formation. The aim of this study is to investigate the survival of cells in biofilms upon exposure to antimicrobials through the interplay of efflux-mediated spatial interactions . To this end, we generated fluorescently labeled E. coli strains that differ in their levels of AcrAB-TolC efflux pump activity and an acrB knockout-strain. The strains were characterized in terms of their antimicrobial susceptibility of three antibiotics, tetracycline, kanamycin, ampicillin, and the biocide benzalkonium chloride. The knockout strain shows higher susceptibility than the wildtype strain, with highest difference observed upon exposure to benzalkonium chloride. The results were confirmed with an efflux activity assay, which showed decreased efflux for the knockout strain as compared to the wildtype. Interestingly, adding the efflux inhibitor PAβN at intermediate concentrations induced bimodality in efflux activity in the wildtype. To investigate the link between colony structure and spatial patterns of efflux pump gene expression, strains with different fluorescent labels and efflux activity were mixed in a 1:1 ratio and grown on agar supplemented with antimicrobials at sub-inhibitory concentrations. Analysis of the colonies with fluorescence microcopy shows that the absence of the AcrAB efflux pump affects the structure of sector formation and morphology within the colony. We observed relatively large sectors with similar surface area for high efflux and low efflux cells in the absence of antimicrobials and at low concentrations. In contrast, sectors are disappearing due a strong intermixing of high and low efflux strains with increasing antibiotic concentration, specifically upon exposure to tetracycline and kanamycin. As next steps, we will perform quantitative analysis of colony images, to better interpret the results, develop a mathematical model of interacting cell types and investigate efflux-based interactions at the single-cell level. Taken together, out data suggest that efflux shapes cell-to-cell interactions and these interactions affect the spatial arrangement and the morphology of biofilms. Understanding the dynamics can provide insights into the emergence of resistance of bacterial communities to antimicrobial environments, the complex interplay of resistance, efflux, and biofilm formation, which potentially gives information to combat biofilm resistance. T2 - Multi-Drug Efflux Systems Gordon Research Conference CY - Lucca, Italy DA - 26.04.2025 KW - Antimicrobial KW - Resistance KW - Tolerance KW - Efflux KW - E. coli PY - 2025 AN - OPUS4-64561 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaut, Valerie T1 - Antibiotic tolerance of biofilms emerging from multicellular effects of antibiotic efflux N2 - Biofilms are multicellular assemblages of bacteria living in a self-produced extracellular matrix. Different mechanisms, like the development of highly tolerant persister cells or increased expression of efflux pumps make them tolerant. Here we want to investigate the emergency of antimicrobial tolerance of multicellular bacterial populations, through the interplay of efflux-mediated spatial interactions and efflux-linked persistence. To this end, we are combining computational modelling with experimentally observations gained from three types of multicellular assemblages, i.e. colonies on agar, multicellular populations grown in a monolayer microfluidic device, and 3D biofilms grown in flow chambers. We generated fluorescently labeled E. coli strains that differ in their levels of AcrAB-TolC efflux pump activity, an acrB knockout-strain and a strain with inducible expression of acrAB. All strains were characterized in terms of their antimicrobial susceptibility of three antibiotics, tetracycline, kanamycin, ampicillin, and the biocide benzalkonium chloride. The knockout strain shows higher susceptibility than the wild type strain, with highest difference when using benzalkonium chlorid e. To investigate the link between colony structure and spatial patterns of gene expression, the strains were mixed equimolar and grown on agar supplemented with antimicrobials. First results show, antimicrobials affect the structure of sector formation and morphology. Cells grown on tetracycline agar show a more finer sector formation. While kanamycin changes the overall colony structure . We will develop a mathematical model and additional experiments with multicellular assemblages to explain the observed interactions and extrapolate the results to more realistic biofilm models. T2 - SPP Conference CY - Berlin, Germany DA - 06.01.2025 KW - Antimicrobial KW - Resistance KW - Tolerance KW - Efflux KW - E. coli PY - 2025 AN - OPUS4-64563 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaut, Valerie T1 - Antibiotic tolerance of biofilms emerging from multicellular effects of antibiotic efflux N2 - Biofilms are multicellular assemblies of bacteria living in a self-produced extracellular matrix. One characteristic of biofilms is that they are difficult to kill. Different mechanisms, like the development of persister cells or efflux pumps which pump some antimicrobials out of the cell, make them tolerant. Our central hypothesis is that efflux pump activity causes emergent antimicrobial tolerance of multicellular bacterial populations, through the interplay of efflux-mediated spatial interactions and efflux-linked persistence. To verify the hypothesis, we combine computational modelling with information gained from 3 types of multicellular assemblies. We are currently generating strains that differ in their levels of efflux activity, mixes are then cultivated together in the 3 model systems. In colonies the link between structure and spatial patterns of gene expression will be characterized. Using a microfluidic device, the interactions range of efflux as a response to different antimicrobials will be determined. In a flow chamber a 3D biofilm will be generated, to investigate the biofilm development over time and persister cell formation. All results will be compared with model predictions. T2 - UNA Workshop CY - Berlin, Germany DA - 29.01.2024 KW - Antibiotic KW - Biofilm KW - Tolerance KW - Efflux PY - 2024 AN - OPUS4-61280 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaut, Valerie A1 - Schreiber, Frank T1 - Antibiotic tolerance of biofilms emerging fro multicellular effects of antibiotic efflux N2 - The overarching goal of this project is to develop a predictive model for efflux-mediated antimicrobial tolerance in bacterial multicellular assemblies. Our central hypostasis is that efflux pump activity causes emergent antibiotic tolerance of multicellular bacterial populations, through the interplay of efflux mediated spatial interactions and efflux-linked persistence. To test this hypothesis, we will use a combination of microscopy, microbial killing assays, computational modelling, and data analysis, integrating information from 3 types of multicellular assembly: colonies, cell-to-cell interactions in a monolayer microfluidic device, and 3D flow chamber biofilms. Building on our preliminary observations, we will experimentally characterize the link between colony structure and spatial patterns of efflux gene expression in strains that differ in their levels of efflux. We will develop a mathematical model to test whether local growth inhibition of neighbors due to effluxing cells, coupled with local environment-dependent regulation of efflux, can account qualitatively for these results. By including persister cell formation in our model we will predict, and measure, the emergent function of antimicrobial tolerance in our colonies. To fully understand how tolerance emerges from the interplay between efflux-mediated spatial interactions and efflux-linked persister cell formation, we need quantitative measurements at the single cell level. To this end, we will use a microfluidic setup with cells growing in a monolayer to qualify in detail the dependence of efflux expression and persister cell formation on nutrient conditions, the correlation between efflux and persister formation, and the spatial range of efflux-mediated neighbour growth inhibition. To predict and quantitatively understand the emergent multicellular function of tolerance, we will perform individual-based modelling of biofilm growth, using as input the parameters measured on the single-cell level with our microfluidics experiments. Our simulations will predict biofilm spatial structure development, patterns of efflux and persister formation and, ultimately, tolerance to antimicrobial challenge. These predictions will be directly tested in flow-cell biofilm experiments. We are currently generating acrAB-tolC knockout-strain, without efflux activity, and a strain with an inducible acrAB-tolC efflux pump. To distinguish the different strains under the microscope, they were labeled with genes encoding for different fluorescent proteins. All strains are currently characterized in terms of growth, minimum inhibitory concentration of different antimicrobial substances, colony morphology, and biofilm formation ability. On the theoretical side, we are currently working on modeling the system at various scales and degree of detail, ranging from coarse-grained continuum models to stochastic, individual-based models. Some exploratory work was doe to test existing software for individual-based modelling that may be adapted for our purpose. Furthermore, we are in the process of developing more coarse-grained models. This work involves some physiological modelling and literature search, focusing on working mechanisms of efflux pumps and kinetic models for import and export of antibiotics. T2 - SPP Meeting CY - Jena, Germany DA - 04.10.2023 KW - Antibiotic KW - Bioilm KW - Tolerance KW - Efflux PY - 2023 AN - OPUS4-59245 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kalbe, Ute T1 - Identifikation und Einordnung von historischen Lehmbauteilen für die Wiederverwendung hinsichtlich Anreicherung von Schadstoffen und bauschädlichen Salzen N2 - Lehmbaustoffe, einschließlich Lehm aus dem historischen Baubestand, bieten ein hohes Potenzial für ihre Wiederverwendbarkeit und die Schonung natürlicher Ressourcen. Zur Bewertung des Wiederverwendungspotenzials gibt es nur wenige Studien hinsichtlich der Schadstoffbelastung und der Anreicherung von Salzen in Gebäuden aus dem historischen Bestand. Tonminerale, die in Lehmbaustoffen als Bindemittel fungieren, können Schadstoffe binden. Die Region Mitteldeutschland ist geprägt durch jahrzehntelange Einwirkung erheblicher Schadstoffemissionen aus der Chemie- und Braunkohleindustrie. Der Eintrag von Schadstoffen in Lehmbaustoffe ist außerdem aus geogenen Hintergrundbelastungen denkbar, z. B. in Auenböden beeinflusst durch Einträge aus dem Erzbergbau. Salzbildende Anionen wie Chloride oder Nitrate können aufgrund ihrer hohen Löslichkeit mittels kapillarer Kräfte durch die Porenstruktur transportiert werden. In Lehmwänden können sie vor allem in oberflächennahen Lagen, in denen höhere Verdunstungsraten vorherrschen, durch Bindung mit in Lösung vorliegenden oder baustoffeigenen Kationen auskristallisieren und bauschädliche Salze ausbilden. Auch durch spezifische Nutzungen akkumulierte Schadstoffe, z. B. durch die Einwirkung von Tabakrauch, könnten theoretisch einer Wiederverwendung von Lehm entgegenstehen. In Anbetracht der Herausforderungen hinsichtlich der klimatischen und gesellschaftlichen Veränderungen, sind wissenschaftliche Erkenntnisse im Lehmbau erforderlich, die eine Integration in eine nachhaltige Kreislaufwirtschaft ermöglichen. Bei bisherigen Gesetzgebungsverfahren zu rezyklierten Baustoffen wurden Lehmbaustoffe noch nicht berücksichtigt. Ziel einer Vorstudie im Rahmen der WIR!-Initiative GOLEHM ist die Überprüfung der Wiederverwendbarkeit Wiederverwendbarkeit von Lehmbaustoffen aus historischen Bauten an Stichproben hinsichtlich der Umwelt- und Nutzerverträglichkeit. Für den Raum Mitteldeutschland können damit Anhaltspunkte darüber gegeben werden, welche Schadstoffe und bauschädlichen Salze in welchem Maße in Lehmbaustoffen aus dem Gebäudebestand erwartet werden können. Daraus können Hinweise zum Umgang mit Lehmbaustoffen aus historischen Gebäuden abgeleitet werden. Darüber hinaus wurden exemplarisch an zwei Gebäuden mikrobiologische Untersuchungen zur Ermittlung einer möglichen Belastung mit Schimmelpilzen vorgenommen. T2 - Lehm 2024 Fachtagung CY - Weimar, Germany DA - 27.09.2024 KW - Lehm KW - Schadstoffe KW - Wiederverwendung KW - Historischer Baubestand PY - 2024 AN - OPUS4-61881 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kalbe, Ute T1 - HistRCL- Vorstudie zur Identifikation und Einordnung von historischen Lehmbauteilen für die Wiederverwendung hinsichtlich der Anreicherung von Schadstoffen und bauschädlichen Salzen N2 - Lehm aus dem historischen Baubestand bietet ein hohes Potenzial für eine Wiederverwendung und die Schonung natürlicher Ressourcen. Anthropogene Einflüsse aus der Industrie der Region Mitteldeutschland und auch die Akkumulation von Schadstoffen durch spezifische Nutzungen sowie durch Feuchteeinfluss angereicherte bauschädliche Salze können einer Wiederverwendung entgegenstehen. Ziel des Projektes war daher die Überprüfung der Rezyklierbarkeit von Lehmbaustoffen aus historischen Bauten hinsichtlich der Umwelt- und Nutzerverträglichkeit. Dafür wurden exemplarisch Wellerlehmgebäude aus dem historischen Bestand mit einer potenziellen Belastung beprobt und untersucht. Die Ergebnisse liefern einen Beitrag, Unsicherheiten bei im Lehmbau tätigen Unternehmen hinsichtlich des sicheren Umganges mit möglichen stofflichen Belastungen abzubauen und diese bei der Einhaltung umweltrechtlicher und kreislaufgerechter Rahmenbedingungen bei der Wiederverwendung von Lehm aus dem historischen Bestand zu unterstützen. T2 - GOLEHM Innovationsforum CY - Halle (Saale), Germany DA - 26.07.2024 KW - Lehm KW - Wiederverwendung KW - Schadstoffe KW - Bauschädliche Salze PY - 2024 AN - OPUS4-61878 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kalbe, Ute A1 - Schröder, Simon Alexander A1 - Richter, Matthias A1 - Horn, Wolfgang A1 - Stephan, Ina A1 - Hohmann, Gloria A1 - Ziegert, Christof T1 - Identifikation und Einordnung von historischen Lehmbauteilen für die Wiederverwendung hinsichtlich Anreicherung von Schadstoffen und bauschädlichen Salzen T1 - Identification and classification of historical earth construction elements for recycling in respect of accumulation of pollutants and structurally damaging salts N2 - Lehmbaustoffe, einschließlich Lehm aus dem historischen Baubestand, bieten ein hohes Potenzial für ihre Wiederverwendbarkeit und die Schonung natürlicher Ressourcen. Zur Bewertung des Wiederverwendungspotenzials gibt es nur wenige Studien hinsichtlich der Schadstoffbelastung und der Anreicherung von Salzen in Gebäuden aus dem historischen Bestand. Tonminerale, die in Lehmbaustoffen als Bindemittel fungieren, können Schadstoffe binden. Die Region Mitteldeutschland ist geprägt durch jahrzehntelange Einwirkung erheblicher Schadstoffemissionen aus der Chemie- und Braunkohleindustrie. Der Eintrag von Schadstoffen in Lehmbaustoffe ist außerdem aus geogenen Hintergrundbelastungen denkbar, z. B. in Auenböden beeinflusst durch Einträge aus dem Erzbergbau. Salzbildende Anionen wie Chloride oder Nitrate können aufgrund ihrer hohen Löslichkeit mittels kapillarer Kräfte durch die Porenstruktur transportiert werden. In Lehmwänden können sie vor allem in oberflächennahen Lagen, in denen höhere Verdunstungsraten vorherrschen, durch Bindung mit in Lösung vorliegenden oder baustoffeigenen Kationen auskristallisieren und bauschädliche Salze ausbilden. Auch durch spezifische Nutzungen akkumulierte Schadstoffe, z. B. durch die Einwirkung von Tabakrauch, könnten theoretisch einer Wiederverwendung von Lehm entgegenstehen. In Anbetracht der Herausforderungen hinsichtlich der klimatischen und gesellschaftlichen Veränderungen, sind wissenschaftliche Erkenntnisse im Lehmbau erforderlich, die eine Integration in eine nachhaltige Kreislaufwirtschaft ermöglichen. Bei bisherigen Gesetzgebungsverfahren zu rezyklierten Baustoffen wurden Lehmbaustoffe noch nicht berücksichtigt. Ziel einer Vorstudie im Rahmen der WIR!-Initiative GOLEHM ist die Überprüfung der Wiederverwendbarkeit Wiederverwendbarkeit von Lehmbaustoffen aus historischen Bauten an Stichproben hinsichtlich der Umwelt- und Nutzerverträglichkeit. Für den Raum Mitteldeutschland können damit Anhaltspunkte darüber gegeben werden, welche Schadstoffe und bauschädlichen Salze in welchem Maße in Lehmbaustoffen aus dem Gebäudebestand erwartet werden können. Daraus können Hinweise zum Umgang mit Lehmbaustoffen aus historischen Gebäuden abgeleitet werden. Darüber hinaus wurden exemplarisch an zwei Gebäuden mikrobiologische Untersuchungen zur Ermittlung einer möglichen Belastung mit Schimmelpilzen vorgenommen. N2 - Earth construction materials, including earth from historical building stock, offer high potential in terms of their recyclability and sparing use of natural resources. Yet, only a few studies have been conducted on the levels of pollutants and the accumulation of salts in buildings from the historical building stock to enable an assessment of the potential for recycling. The aim of a preliminary study as part of the GOLEHM Initiative from WIR! is to use spot checks to review the recyclability of earth construction materials from historical buildings in terms of environmental impact and tolerance by users. This could provide indicators for the Central Germany region on which pollutants and structurally damaging salts can be expected in earth construction materials from the building stock and to what extent, allowing conclusions to be drawn on how to manage earth construction materials from historical buildings. Additionally, microbiological inspections of two sample buildings were performed to assess a potential contamination with mould. T2 - Lehm 2024 Fachtagung CY - Weimar, Germany DA - 27.09.2024 KW - Lehm KW - Wiederverwendung KW - Kreislaufwirtschaft KW - Schadstoffe KW - Bauschädliche Salze PY - 2024 SP - 1 EP - 8 CY - Weimar AN - OPUS4-61883 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kanaris, Orestis T1 - Metabolic niches and persistence of antibiotic resistant bacteria in the environment N2 - Background and Aim: Wastewater treatment plants are considered as hotspots for the development and spread of antimicrobial resistance. Antimicrobial resistant bacteria (ARB) can persist in the environment for long periods of time, despite metabolic fitness costs that can arise with resistance. We are interested in understanding the mechanisms, which allow ARB to persist in the environment. More specifically, we want to identify metabolic niches that can select for resistant bacteria. Procedure/Method: 62 E. coli strains isolated from different WWTPs in Norway were used. The isolates have different levels of resistance to 14 antibiotics. The susceptibility of the isolates to 3 disinfectants was determined. In addition, genome scale metabolic models (GEMs) were constructed and the growth of the strains was simulated in the presence of 198 different carbon sources. Furthermore, the growth rates of the isolates were measured in the presence of 3 carbon sources. Findings/Results: Many of the isolates have high resistance to multiple antibiotics but only few of the isolates have higher minimum inhibitory concentrations to the disinfectants, compared to an E. coli laboratory strain. With the GEMs, we identified 40 carbon sources that can be utilized for growth only by a portion of all the isolates. The prediction accuracy of the GEMs was 93% in the case of D-Malate. A group of 10 isolates was identified of which 5 isolates are resistant to ciprofloxacin, gentamicin and tetracycline and can grow on Sucrose but not on D-Malate and the other 5 isolates are susceptible to the same 3 antibiotics but can grow on D-Malate and not on Sucrose. Implications/Applications: Our data suggest that changing the available carbon source could shift the selection advantage between resistant and susceptible bacterial strains. If this strategy is confirmed experimentally, it could be applied to reduce the number of ARB in environments like wastewater. T2 - Conference on the Environmental dimentions of antimicrobial resistance 7 CY - Montreal, Canada DA - 26.05.2024 KW - Antimicrobial resistance KW - Wastewater PY - 2024 AN - OPUS4-61410 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kanaris, Orestis T1 - Identification of metabolic niches and their association to the persistence of antibiotic resistant bacteria in wastewater N2 - Wastewater treatment plants (WWTP) are hotspots for the development and spread of antimicrobial resistance. Antimicrobial resistant bacteria (ARB) can persist in the environment for long periods of time, despite metabolic fitness costs that often arise with resistance. Recent research efforts are striving to uncover the role of bacterial metabolism for the ecology and evolution of antibiotic resistance. The aim of this study is to understand the ecological mechanisms, which allow ARB to persist in the environment. More specifically, we aim to identify metabolic niches that can select for and against resistant bacteria. 62 E. coli strains isolated from different WWTPs with different levels of resistance to 14 antibiotics and 3 disinfectants were assembled, sequenced, and phenotypically characterized. Next, genome scale metabolic models (GEMs) were constructed, and the growth of the strains was simulated in the presence of 298 different carbon sources. Furthermore, the growth rates of the isolates were measured in the presence of 3 carbon sources to verify the model predictions. Competition experiments with synthetic microbial communities consisting of a selection of 10 WWTP isolates, 5 of which were antibiotic resistant and 5 sensitive, were carried out in minimal medium with different carbon sources. Population dynamics modelling was used to simulate the competition of isolates under different conditions. The isolates have a wide range of susceptibility to the antibiotics, while disinfectants result in a narrower range of susceptibility. GEMs identified 40 carbon sources that can be utilized for growth only by a portion of all the isolates. The prediction accuracy of the GEMs was 93% in the case of D-malate. A range of WWTP isolates were identified which use D-malate as carbon source and are susceptible to specific antibiotics. In contrast, antibiotic-resistant WWTP isolates were identified that did use sucrose as carbon source but not D-malate. Competition experiments demonstrated that changing the carbon source of the medium from sucrose to D-malate resulted in selection against the resistant isolates. Modelling the competition between isolates under different conditions suggests that adding a carbon source to a bacterial community under specific conditions could exclude resistant bacteria from a microbial community. Our data suggest that changing the available carbon source could shift the selection advantage between resistant and susceptible bacterial strains. If this strategy is confirmed experimentally in complex microbial communities, it could be applied to reduce the number of ARB in environments such as wastewater. T2 - FEMS micro Konferenz CY - Milan, Italy DA - 14.07.2025 KW - AMR KW - Wastewater KW - Genome-scale metabolic model PY - 2025 AN - OPUS4-64659 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kanaris, Orestis T1 - Metabolic niches and persistence of antibiotic resistant bacteria in the environment N2 - Background and Aim: Wastewater treatment plants are considered as hotspots for the development and spread of antimicrobial resistance. Antimicrobial resistant bacteria (ARB) can persist in the environment for long periods of time, despite metabolic fitness costs that can arise with resistance. We are interested in understanding the mechanisms, which allow ARB to persist in the environment. More specifically, we want to identify metabolic niches that can select for resistant bacteria. Procedure/Method: 62 E. coli strains isolated from different WWTPs in Norway were used. The isolates have different levels of resistance to 14 antibiotics. The susceptibility of the isolates to 3 disinfectants was determined. In addition, genome scale metabolic models (GEMs) were constructed and the growth of the strains was simulated in the presence of 198 different carbon sources. Furthermore, the growth rates of the isolates were measured in the presence of 3 carbon sources. Findings/Results: Many of the isolates have high resistance to multiple antibiotics but only few of the isolates have higher minimum inhibitory concentrations to the disinfectants, compared to an E. coli laboratory strain. With the GEMs, we identified 40 carbon sources that can be utilized for growth only by a portion of all the isolates. The prediction accuracy of the GEMs was 93% in the case of D-Malate. A group of 10 isolates was identified of which 5 isolates are resistant to ciprofloxacin, gentamicin and tetracycline and can grow on Sucrose but not on D-Malate and the other 5 isolates are susceptible to the same 3 antibiotics but can grow on D-Malate and not on Sucrose. Implications/Applications: Our data suggest that changing the available carbon source could shift the selection advantage between resistant and susceptible bacterial strains. If this strategy is confirmed experimentally, it could be applied to reduce the number of ARB in environments such as wastewater. T2 - International Biodeterioration and Biodegradation Symposium 19 CY - Berlin, Germany DA - 09.09.2024 KW - Antimicrobial resistance KW - Wastewater PY - 2024 AN - OPUS4-61412 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kanaris, Orestis T1 - Consequences of benzalkonium chloride tolerance on the development of antibiotic resistance in E. coli N2 - Biocides are used in large amounts in industrial, medical, and domestic settings. Benzalkonium chloride (BAC) is a commonly used biocide, for which previous research revealed that Escherichia coli can rapidly adapt to tolerate BAC-disinfection, with consequences for antibiotic susceptibility. However, the consequences of BAC-tolerance for selection dynamics and resistance evolution to antibiotics remain unknown. Here, we investigated the effect of BAC-tolerance in E. coli on its response upon challenge with different antibiotics. Competition assays showed that subinhibitory concentrations of ciprofloxacin - but not ampicillin, colistin and gentamicin - select for the BAC-tolerant strain over the BAC-sensitive ancestor at a minimal selective concentration of 0.0013-0.0022 µg∙mL-1. In contrast, the BAC-sensitive ancestor was more likely to evolve resistance to ciprofloxacin, colistin and gentamicin than the BAC-tolerant strain when adapted to higher concentrations of antibiotics in a serial transfer laboratory evolution experiment. The observed difference in the evolvability of resistance to ciprofloxacin was partly explained by an epistatic interaction between the mutations conferring BAC-tolerance and a knockout mutation in ompF encoding for the outer membrane porin F. Taken together, these findings suggest that BAC-tolerance can be stabilized in environments containing low concentrations of ciprofloxacin, while it also constrains evolutionary pathways towards antibiotic resistance. T2 - µClub Seminar CY - Berlin, Germany DA - 23.05.2025 KW - Biocides KW - AMR KW - Resistance evolution PY - 2025 AN - OPUS4-64658 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kanaris, Orestis T1 - Consequences of tolerance to disinfectants on the evolution of antibiotic resistance in E. coli N2 - Biocides are used as disinfectants and preservatives; one important active substance in biocides is benzalkonium chloride (BAC). BAC-tolerant bacterial strains can survive short treatments with high concentrations of BAC. BAC tolerance and resistance have been linked to antibiotic resistance. Here, the selection dynamics between a BAC-tolerant Escherichia coli strain and a sensitive wild type were investigated under four conditions: in the absence of antibiotics and in the presence of three different sub-inhibitory concentrations of the antibiotic ciprofloxacin in liquid cultures. The wild type was selected over the BAC-tolerant strain in the absence of antibiotics, while the BAC-tolerant strain was selected over the wild type at all ciprofloxacin concentrations investigated, with a minimum selection concentration (MSC) of 1/10th of the minimum inhibitory concentration (MIC) of the wild type. Furthermore, the evolvability of resistance of the two strains to inhibitory concentrations of ciprofloxacin was assessed by performing a serial dilution evolution experiment with gradually increasing ciprofloxacin concentrations. The wild type had a higher probability to develop resistance to ciprofloxacin than the tolerant strain. By the end of the evolution experiment both strains evolved to grow at the highest ciprofloxacin concentration investigated, which was 2048 ×MIC of the wild type. The importance of these results is highlighted by the fact that concentrations of ciprofloxacin well above the calculated MSC can be found in environmental samples such as hospital wastewaters and livestock slurry. In turn, BAC is used as a disinfectant in the same settings. Thus, the selection of BAC-tolerant strains at sub-inhibitory concentrations of ciprofloxacin can contribute to the stabilization and spread of BAC-tolerance in natural populations. The prevalence of such strains can impair the effects of BAC disinfections. T2 - µClub seminar series CY - Berlin, Germany DA - 15.12.2023 KW - Antimicrobial resistance PY - 2023 AN - OPUS4-59222 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kanaris, Orestis T1 - Consequences of benzalkonium chloride tolerance in Escherichia coli: Effects on selection and evolution in the presence of ciprofloxacin N2 - We investigated the selection dynamics between a benzalkonium chloride (BAC)-tolerant Escherichia coli strain (S4) and a sensitive wild type under four conditions: in the absence of antibiotics and in the presence of three different sub-inhibitory concentrations of the antibiotic ciprofloxacin in liquid cultures. The wild type was selected over the BAC-tolerant strain in the absence of antibiotics, while the opposite was observed at all ciprofloxacin concentrations investigated.Furthermore, we assessed the evolvability of resistance of the two strains to inhibitory concentrations of ciprofloxacin by performing a serial dilution evolution experiment with gradually increasing ciprofloxacin concentrations. The wild type had a higher probability to develop resistance to ciprofloxacin than the tolerant strain. By the end of the evolution experiment both strains evolved to grow at the highest ciprofloxacin concentration investigated, which was 2048 ×MIC of the wild type. T2 - 6th international symposium on the environmental dimention of antibiotic resistance-EDAR 6 CY - Gothenburg, Sweden DA - 22.09.2022 KW - Antimicrobial resistance KW - Tolerance KW - Experimental evolution KW - Selection PY - 2022 AN - OPUS4-56808 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - 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 - Keshmiri, Hamid T1 - Bidiffractive leaky-mode biosensor N2 - This study details a thorough analysis of leaky and waveguide modes in biperiodic diffractive nanostructures. By tuning diffraction orders and subsequently confining local density of optical states at two distinct resonance wavelengths, we present a highly sensitive refractive index biosensing platform that can resolve 35.5 to 41.3 nm/RIU of spectral shift for two separate biological analytes. T2 - EMBL Symposium: Seeing is Believing - Imaging the Molecular Processes of Life CY - Heidelberg, Germany DA - 04.10.2023 KW - Optics PY - 2023 AN - OPUS4-59247 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kirsch, Klemens T1 - Microbiologically Influenced Corrosion of Cast Iron Containers for High-Level Nuclear Waste Disposal N2 - Ductile and corrosion resistant cast iron is investigated as a potential container material to store high-level nuclear waste (HLW) in deep geological repositories (DGR) in claystone bedrock. The dynamic corrosion process is dependent on the conditions present in the DGR which are influenced and/or controlled by geochemical parameters (e.g., redox potential, pH, presence of and ionic concentration in (pore-)water), physical parameters (e.g., pressure), and the influence of metabolically active microorganisms. Cast iron corrosion will occur at the intersection of container and its decontaminable coating with the bentonite backfill material which contains natural microbial populations. The conditions in a DGR are simulated in microcosm experiments to investigate the impact of microbiologically influenced corrosion (MIC); the microcosms contain: B27 bentonite, synthetic pore water, N2 or N2-CO2 atmosphere, cast iron coupons, as well as the bacterium Desulfosporosinus burensis (isolated from repository depth in Buré, France). Three coupon configurations will be used: untreated, coated with decontaminable coating, and coated with decontaminable coating which has been damaged to simulate possible damages. The microcosms will be examined for bio- and geochemical parameters, such as pH, redox potential, mineral phases, sulphate concentration, Fe(II):Fe(III), changes in microbial populations, and the corrosion process for formation of corrosion products, and potential microbial influence, after a 270-day incubation period at 25°C under anaerobic conditions. In subsequent experiments, the sorption behavior of lanthanides and actinides onto the membranes of viable cells and spores of D. burensis, as well as the surface of corroded cast iron coupons will be investigated. T2 - 8th International Workshop on Long-term Prediction of Corrosion in Nuclear Waste Systems 2022 CY - Baden, Switzerland DA - 21.06.2022 KW - Microbiologically influenced corrosion (MIC) KW - Cast iron KW - Nuclear waste disposal PY - 2022 AN - OPUS4-55154 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koerdt, Andrea T1 - The Power of networks – COST Action CA20130 N2 - For optimal research on microbiologically influenced corrosion (MIC), balanced and interdisciplinary cooperation is extremely important. However, differing perspectives, thought processes, and even variations in nomenclature/terminology often hinder the establishment of effective collaborations. Over the past four years, COST Action Euro-MIC (CA20130) has effectively addressed these discrepancies. Through regular meetings, conferences, and scientific exchanges, a large international network has been established. Many scientific findings and results have been achieved through scientific, interdisciplinary exchange within the international network. The upcoming presentation will highlight three examples (among many others) that have resulted in successful collaborations, third-party funding applications, publications, or outstanding results and emphasize that successful results in MIC research, facilitated by an interdisciplinary network, can lead more quickly to meaningful and application-oriented findings. Project 1&2 describe two different kinds of Projects related to the use of Nanoparticles; one is about the efficacy testing of novel Nanoparticles. Project 2 deals about how to apply already working and tested nanoparticles to different materials and conditions. Project 3a is related to the energy sector; a crucial part of our society, and currently undergoing significant changes. Climate change, rising temperatures, increased use of fertilizers and other environmental pollutants have led to an increasing occurrence of microorganisms and contamination in some sectors. But how we deal with “baggage” from the past and store nuclear waste without harm or risk for human and environment, but also how to transfer the gained knowledge to areas like safe Hydrogen storage in geological underground formation. T2 - ISMOS10 CY - Nashville, TN, USA DA - 11.08.2025 KW - COST Action CA20130 KW - MIC KW - STSM Grants KW - Networking PY - 2025 AN - OPUS4-64295 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koerdt, Andrea T1 - Euro-MIC COST Action CA20130 Closing Workshop & Conference 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 - Final COST Action Conference - Horsens CY - Horsens, Denmark DA - 17.09.2025 KW - MIC KW - COST Action Euro-MIC KW - Interdisciplinarity PY - 2025 AN - OPUS4-64299 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koerdt, Andrea T1 - Cost action EURO MIC (CA20130) N2 - Vorstellung des vor kurzen angelaufenen EU-Projekts: COST ACTION EURO MIC ( CA20130). Die BAM hat hierbei die Rolle des Chairs sowie Grant-Holding Institute. COST fördert internationale Netzwerk Aktivitäten. Durch COST Action können neue Kooperationen (Industrie, Akademie oder Politk) entstehen. T2 - Dechema CY - Online meeting DA - 10.11.2021 KW - Netzwerk KW - COST KW - Mikrobiell beeinflusste Korrosion KW - MIC PY - 2021 AN - OPUS4-54023 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koerdt, Andrea T1 - Euro-MIC 2021-2025, our journey, and paths forward N2 - Microbiologically Influenced Corrosion (MIC) refers to the detrimental effects on materials caused by microorganisms, and it is becoming an increasingly significant issue for society. Unlike the USA, Canada, and Australia, Europe has less developed cooperation on MIC. Although several research groups and industrial stakeholders are addressing MIC, discussions remain fragmented, and information exchange is limited. A truly transdisciplinary approach is rarely seen. As a result, Europe often relies on methods, preventive measures, and standards from other regions, as there are no equivalent European standards. This situation makes Europe a) highly dependent, and b) in some cases, unable to use certain measures or standards due to European legal restrictions (e.g., the use of biocides). In 2021, researchers established the “Euro-MIC” network, financially supported by the EU project “COST-Action,” to tackle these issues. Through COST-Action, Euro-MIC aims to facilitate necessary interactions, communication, knowledge sharing, and training for personnel and researchers across various disciplines. COST-Action supports network activities, workshops, training schools, conferences, and more. Euro-MIC aspires to position Europe as a leader in MIC, promoting ideas on par with other nations while upholding European values and ensuring greater protection for people, property, and the environment. In this presentation, I will briefly introduce the principles of COST Action and highlight the significant opportunities provided by this EU-funded project. COST Action fosters interdisciplinarity, networking, training, scientific exchange, and the promotion of young scientists. By showcasing some examples of CA20130 COST ACTION Euro-MIC, I hope to demonstrate that COST Action is not only relevant for addressing MIC but can also be applied to other important topics and sectors. T2 - Unseen Corrosion: Unveiling Hidden Threats and Innovating Monitoring Solutions CY - Bergen, Norway DA - 15.05.2025 KW - COST Action CA20130 KW - MIC KW - Network KW - Corrosion KW - Microorganisms PY - 2025 UR - https://www.norceresearch.no/en/events/unseen-corrosion AN - OPUS4-63726 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koerdt, Andrea T1 - Mikrobiell beeinflusste Korrosion (MIC) – Wenn MIC dann BAM N2 - In dieser Präsentation wurden dem Beirat Umwelt die High-Lights und der weitere Ausblick des Foresight Process MIC vorgestellt. Im Fokus stehen hierbei insbesondere die neu angelaufenen Projekte: COST Action Euro-MIC MIC im Endlager Hydrogen: MIC & Wasserstoffversprödung Biorezeptivität von Betonoberflächen Mitigation schwarze Pilze WIPANO ResTest T2 - Beirat Umwelt CY - Online meeting DA - 11.03.2022 KW - MIC KW - Hi-Tension KW - Projekte PY - 2022 AN - OPUS4-54463 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 - Koerdt, Andrea T1 - COST-Action - EURO-MIC (CA20130) European MIC Network - New paths for science, sustainability and standards N2 - Microbiologically Influenced Corrosion (MIC) is a phenomenon that is increasingly becoming a problem for the society. MIC describes the negative effects a material can experience due to the presence of microorganisms. In Europe, several research groups/ other industrial stakeholders are already dealing with MIC. Unfortunately, the discussions are fragmented and the exchange of information is limited. A true transdisciplinary approach is hardly ever experienced, although this would be logical for this material/biology related challenge. USA, Canada and Australia have strong networks, and develop methods, prevention measures and standards, which Europe is forced to use, since nothing similar exists for a network and combined knowledge to design them according to european standards. This makes Europe extremely dependent and, in some cases, the potential measures or standards cannot been used because the suggested solutions are prohibited by European laws (e.g. use of biocides). Therefore, it is important to initiate a new European MIC-network. Europe needs to combine the efforts as experts in different fields and develop prevention measures according to the European rules, in close cooperation with industry and plant operators and owners of critical infrastructure. This COST Action will provide the necessary interaction and communication, knowledge sharing, training of personnel and of researchers of different disciplines. This will bring Europe to a leading role in this process, bringing ideas on an equal level with other nations, considering the values which are important for Europe and attitudes (e.g.environmental protection) and representing greater protection for people, property and the environment. The main aim and objective of the Action is to , in the context of MIC-research/control, encourage a fluent/synergistic collaboration/communication, closing the gap between materials scientists, engineers, microbiologists, chemists and integrity managers to encourage sufficient interaction between academia and industry. This Action will create a common MIC-Network, including the important stakeholders. T2 - EuroCorr CY - Online meeting DA - 19.09.2021 KW - COST Action KW - MIC KW - Interdisciplinary KW - Stakeholder KW - Academia PY - 2021 AN - OPUS4-53382 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koerdt, Andrea T1 - Wasserstofflagerung in unterirdischen geologischen Formationen und potenzielle Risiken durch Mikroorganismen N2 - Bei dem Vortrag werden die potentiellen mikrobiologischen Einflüsse im Falle der Lagerung von Wasserstofflagerung in unterirdischen geologischen Formationen vorgestellt, die Zusammenarbeit mit internen und auch externen Partnern. Der Fokus liegt dabei auf UGF; anaerobe Umgebungen, Sulfate reduzierenden Bakterien, methanogenen Archaea, weiterleitenden Systeme und die Kombination der Untersuchung abiotisch/biotische T2 - VDI-Schadensanalyse (49) CY - Würzburg, Germany DA - 17.10.2023 KW - MIC KW - Wasserstofflagerung KW - Unterirdische Speicher KW - Kontamination von H2 KW - H2-Abbau KW - Mikroorganismen KW - Biotische/abiotische Faktoren PY - 2023 AN - OPUS4-58645 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Koerdt, Andrea T1 - Mikrobiell beeinflusste Korrosion – die Testungsart entscheidet N2 - In diesem kurzem Artikel wird die neue Testungsart druch Hi-Tension vorgestellt. Der Hauptfokus liegt dabei auf die Umweltsimulations-Säule, mit deren Hilfe die bisher bekannten Korrosionsraten von methanogenen Archaea signifikant erhöht wurden. KW - Hi-Tension KW - MIC KW - Methanogene KW - Umweltsimulation PY - 2021 DO - https://doi.org/10.1007/s12268-021-1507-7 VL - 27 SP - 100 EP - 100 PB - BIOspektrum Springer AN - OPUS4-52193 LA - deu 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 - Koerdt, Andrea T1 - Mikrobielle Zusammensetzung im Wassertank N2 - Der Fachbereich 7.6 untersucht seit einiger Zeit an Auslagerungsständen auf dem Testgelände in Horstwalde Korrosion im maritimen Bereich. Im Moment läuft das System mit künstlichem Meerwasser und simuliert die Bewitterung von Metallproben unter angenäherten klimatischen Bedingungen ähnlich zum natürlichem Habitat. Im Laufe der Zeit konnte nicht intendierter mikrobieller bewuchs beobachtet werden. Es stellte sich die Frage, welche Mikroorganismen vorlagen und ob diese einen Einfluss auf die Korrosionsuntersuchungen haben könnte. Aus diesem Grund wurden 16S-rRNA Untersuchungen durchgeführt welche alle drei Domänen des Lebens widerspiegeln Bakterien, Archaea und Eukaryoten. Es konnte gezeigt werden, dass über 95% der vorliegenden Biomasse Grünalgen waren, die durch Licht Eintrag in den Container Photosynthese betrieben und dadurch an Biomasse zunahmen. Des weiteren konnten Bakterien detektiert werden, welche in der Regel halophilen und aeroben Habitaten zu finden sind. Allerdings wurden auch Sulfat reduzierende Bakterien (MIC) detektiert, wenn auch in einem geringen prozentualen Anteil. Es muss allerdings Berücksichtigt werden, dass die mikrobielle Zusammensetzung sich im Laufe der Zeit weiter ändern kann. Als Ursprung der Biomasse wird, das künstliche Sediment vermutet. Außerdem wäre es für zukünftige Experiment denkbar, das System mit echtem Sediment aus dem marinen Habitat anzuimpfen. T2 - Dechema CY - Online meeting DA - 10.11.2021 KW - Mikroorganismen KW - Mikrobielle Gemeinschaft KW - Korrosion KW - Simulation PY - 2021 AN - OPUS4-54035 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koerdt, Andrea T1 - Mikrobielle Einflüsse auf Wasserstoffspeicherung: Materialien, Abbauprozesse und Teststrategien N2 - Wasserstoff gilt als Schlüsseltechnologie für die Energiewende – doch seine sichere Anwendung stellt neue Anforderungen an Technik, Infrastruktur und Personal. Die Veranstaltung „H₂ Sicherheit“ bietet eine umfassende Plattform, um sich über die sicherheitsrelevanten Aspekte von Wasserstoff zu informieren und praxisnahe Lösungen kennenzulernen. Expert:innen aus Forschung, Industrie und Netzbetrieb geben Einblicke in aktuelle Entwicklungen, Herausforderungen und Best Practices. Fokus dieser Präsentation war der Mikrobielle Einfluss bei der unterirdischen Speicherung von Wasserstoff und das neuartige Testsystem (MISTRAL) T2 - DVGW- H₂ Sicherheit | 26. – 27. November 2025 CY - Online meeting DA - 26.11.2025 KW - MIC KW - MISTRAL KW - Hochdruckbehälter KW - Wasserstoff KW - Unterirdische geologische Formationen PY - 2025 AN - OPUS4-64890 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koerdt, Andrea T1 - Hydrogen storage & Microbiologically influenced corrosion - Improved test system for Stability and Durability of the Materials & Gas N2 - Underground hydrogen storage (UHS) is a strategic step towards implementing the hydrogen economy. Achieving the required infrastructure by 2050 necessitates advancements in hydrogen-dedicated assets and the evaluation of existing infrastructure. The unique conditions in UHS require an experimental set-up to simulate UHS operating conditions, which allows to assess the readiness of current storage and transmission for hydrogen, and develop new technologies for material-resistance, operational-simulations, and risk-assessments. In addition to the physical/chemical conditions in UHS (e.g., salinity, hydrogen concentration, operating temperature/-pressure, water content), biological threats must also be considered. Therefore, we present here a high-pressure-set-up, developed for research/-industrial testing purposes. Currently, UHS-experiments for microbiologically-influenced-corrosion (MIC) are performed in standard autoclaves with relatively high volumes/pressures; they were primarily designed for material-specific investigations. While these methods provided some useful information for biological questions, they had significant limitations. Besides, the rapid depressurization that occurs with standard autoclaves can greatly affect materials, especially amorphous materials like polymers, causing damage that isn't due to the actual hydrogen storage. This presents a challenge, as the test results may not accurately reflect real-world conditions. To address these issues, specialized autoclaves have been developed to allow for slower depressurization while also enabling continuous monitoring of gases and liquids during the experiment. Such modifications could help obtain more accurate and reliable data. The novel UHS-simulation-set-up presented here is designed with a controlled independently temperature and pressure. Field samples can be used to mimic geology, water chemistry, construction materials, and microbiological conditions. Most significant advantages of the set-up are: 1. It allows for liquid addition during the test, enabling the study of biocides or the evaluation of operating setups. 2. It permits liquid/-gas sampling during the test, allowing for more efficient monitoring of testing conditions and a better understanding of the process over time. Additionally, a low-release function is added, which is particularly important for studying MIC to avoid negative side effects, on the material (e.g. polymers/corrosion product-layer/cells itself) which might occur due to the fast pressure release. T2 - MATHEA | MATerials in Hydrogen related Energy Applications 2025 CY - Hamburg, Germany DA - 24.06.2025 KW - MIC KW - MISTRAL KW - Underground storage KW - Hydrogen KW - Polymer KW - Metal PY - 2025 AN - OPUS4-63567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koerdt, Andrea T1 - The impact and potential of halophilic microorganisms on alternative fuels N2 - As more industrial interests focusing on using salt caverns and repurposed gas or petroleum reservoirs for alternative fuel storage, i.e. CO2/H2, the question raises whether microorganisms may impact the infrastructure, gas purity and storage condition over time. Environments with high salinity (> 1.5 Meq of NaCl) are resided by halophiles (salt-loving microorganisms). To compensate for the intensive osmotic stress, they have resorted to two main adaptation strategies: 1) production of compatible solutes and 2) accumulation of intracellular KCl. Microbial community analysis of several high salinity environments revealed a number of recurring genera, including Halomonas and Halanaerobium. However, the impact of halophiles on the overall integrity and stability of the storage facilities remain largely unknown. To evaluate the suitability and stability of saline storage facilities, several model halophilic microorganisms, such as members of Halomonas, will be selected as testing subjects. First, the impact of halophiles on the infrastructure will be determined using an integrative approach by combining a number of techniques, including electrochemistry, TOF-SIMS, SEM/FIB/EDS and FIB-TEM. Second, the abilities of halophiles to alter the fuel composition (i.e. increase/decrease the fractions of H2) will be monitored using gas chromatography by growing them under high pressure. As a result of climate change and the accompanying mandatory shift to renewable energy resources, microorganisms will continue to play an important role in the energy sector, both to their benefit and detriment. Thus, it is important to achieve a certain level of understanding regarding the activities and mechanisms of halophiles prior to large-scaled excursions. T2 - ISMOS-8 CY - Online meeting DA - 07.06.2021 KW - Microbiologically influenced corrosion KW - Hydrogen KW - Gas storage KW - Contamination PY - 2021 AN - OPUS4-52891 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koerdt, Andrea T1 - Exploring Microbial Impacts on Hydrogen Storage: - A Novel System for Corrosion Testing of Gas- and Material Degradation N2 - Underground hydrogen storage (UHS) is a strategic step towards implementing the hydrogen economy. Achieving the required infrastructure by 2050 necessitates advancements in hydrogen-dedicated assets and the evaluation of existing infrastructure. The unique conditions in UHS require an experimental set-up to simulate UHS operating conditions, which allows to assess the readiness of current storage and transmission for hydrogen, and develop new technologies for material-resistance, operational-simulations, and risk-assessments. In addition to the physical/chemical conditions in UHS (e.g., salinity, hydrogen concentration, operating temperature/-pressure, water content), biological threats must also be considered. Therefore, we present here a high-pressure-set-up, developed for research/-industrial testing purposes. Currently, UHS-experiments for microbiologically-influenced-corrosion (MIC) are performed in standard autoclaves with relatively high volumes/pressures; they were primarily designed for material-specific investigations. While these methods provided some useful information for biological questions, they had significant limitations. The novel UHS-simulation-set-up presented here is designed with a controlled independently temperature and pressure. Field samples can be used to mimic geology, water chemistry, construction materials, and microbiological conditions. Most significant advantages of the set-up are: 1. It allows for liquid addition during the test, enabling the study of biocides or the evaluation of operating setups. 2. It permits liquid/-gas sampling during the test, allowing for more efficient monitoring of testing conditions and a better understanding of the process over time. Additionally, a low-release function is added, which is particularly important for studying MIC to avoid negative side effects, on the material (e.g. polymers/corrosion product-layer/cells itself) which might occur due to the fast pressure release T2 - ISMOS10 CY - Nashville, TN, USA DA - 11.08.2025 KW - MIC KW - MISTRAL KW - Corrosion KW - Environmental simulation KW - Metall KW - Polymer PY - 2025 AN - OPUS4-64297 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Koerdt, Andrea A1 - An, Biwen Annie A1 - Deland, Eric ED - Eibergen, N. ED - Poulassichidis, T. T1 - Novel Multiport Flow-Column Corrosion Monitoring System (MFC) Revealed High Corrosion Rates by Corrosive Methanogenic Archaea N2 - MFC was used to study the corrosiveness of iron-utilizing methanogen, Methanobacterium IM1 under flow conditions. Comparing against electrical SRM, Desulfovibrio ferrophilus IS5, results showed under standard mesophilic conditions, average corrosion rates of Methanobacterium IM1 was double that of SRM. The highest corrosion rate of Methanobacterium IM1 reached up to 0.60 mm/yr under neutral conditions, and severe pitting was observed on the iron surface. Furthermore, the corrosion products of Methanobacterium IM1 were characterized with TOF-SIM, FIB-SEM and EDX, and preliminary results revealed FeCO3 is not the only corrosion product of Mi-MIC, as previously reported. Under low pH conditions, the maximum corrosion rate of Methanobacterium IM1 reached 1.57 mm/yr, which resulted in severed deformity of the iron specimen. Additional comparisons using different types of incubation material were conducted to standardize MFC MIC testing. T2 - Corrosion 2021 CY - Online Meeting DA - 19.04.2021 KW - MIC KW - Microbiologically influenced corrosion KW - Biocorrosion KW - Hi-Tension KW - Environmental condition KW - Flow Model KW - Modelling KW - Korrosion PY - 2021 UR - https://my.nace.org/PaperTrail/Authors/Submission.aspx?id=2b6387be-7390-ea11-813a-005056a95a7c SP - Paper C2021-16303, 1 AN - OPUS4-52480 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Koerdt, Andrea A1 - Gerengi, Husnu A1 - Kaya, Ertugrul A1 - M. Solomon, Moses A1 - Snape, Matthew T1 - Advances in the Mitigation of Microbiologically Influenced Concrete Corrosion: A Snapshot N2 - Concrete, a versatile construction material, faces pervasive deterioration due to microbiologically influenced corrosion (MIC) in various applications, including sewer systems, marine engineering, and buildings. MIC is initiated by microbial activities such as involving sulfate-reducing bacteria (SRB), sulfur-oxidizing bacteria (SOB), etc., producing corrosive substances like sulfuric acid. This process significantly impacts structures, causing economic losses and environmental concerns. Despite over a century of research, MIC remains a debated issue, lacking standardized assessment methods. Microorganisms contribute to concrete degradation through physical and chemical means. In the oil and gas industry, SRB and SOB activities may adversely affect concrete in offshore platforms. MIC challenges also arise in cooling water systems and civil infrastructures, impacting concrete surfaces. Sewer systems experience biogenic corrosion, primarily driven by SRB activities, leading to concrete deterioration. Mitigation traditionally involves the use of biocides and surface coatings, but their long-term effectiveness and environmental impact are questionable. Nowadays, it is important to design more eco-friendly mitigation products. The microbial-influenced carbonate precipitation is one of the green techniques and involves incorporating beneficial bacteria with antibacterial activity into cementitious materials to prevent the growth and the formation of a community that contains species that are pathogenic or may be responsible for MIC. These innovative strategies present promising avenues for addressing MIC challenges and preserving the integrity of concrete structures. This review provides a snapshot of the MIC in various areas and mitigation measures, excluding underlying mechanisms and broader influencing factors. KW - MIC KW - Corrosion KW - Concrete KW - Environment PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-619218 DO - https://doi.org/10.3390/ma17235846 VL - 17 IS - 23 SP - 1 EP - 19 PB - MDPI AN - OPUS4-61921 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Kunte, Hans-Jörg A1 - Schwarz, T. A1 - Galinski, E. A. ED - Lee, N. M. T1 - The compatible solute ectoine: protection mechanisms, strain development, and industrial production N2 - Bacteria, Archaea, and Eukarya can adapt to saline environments by accumulating compatible solutes in order to maintain an osmotic equilibrium. Compatible solutes are of diverse chemical structure (sugars, polyols, amino acid derivatives) and are beneficial for bacterial cells not only as osmoregulatory solutes but also as protectants of proteins by mitigating detrimental effects of freezing, drying, and high temperatures. The aspartate derivative ectoine is a widespread compatible solute in Bacteria and possesses additional protective properties compared with other compatible solutes and stabilizes even whole cells against stresses such as ultraviolet radiation or cytotoxins. Here, it is our intention to go beyond a simple description of effects, but to depict the molecular interaction of ectoine with biomolecules, such as proteins, membranes, and DNA and explain the underlying principles. The stabilizing properties of ectoine attracted industry, which saw the potential to market ectoine as a novel active component in health care products and cosmetics. In joint efforts of industry and research, a large-scale fermentation procedure has been developed with the halophilic bacterium Halomonas elongata used as a producer strain. The development and application of ectoine-excreting mutants from H. elongata (“leaky” mutants) allow for the annual production of ectoine on a scale of tons. The details of the strain development and fermentation processes will be introduced. KW - Ectoine KW - Biotechnology KW - Compatible solute KW - Preferential exclusion KW - Osmophobic effect PY - 2020 SN - 978-3-11-042773-8 SP - 121 EP - 136 PB - De Gruyter AN - OPUS4-51472 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marano, Roberto T1 - A Customizable Procedure for Predicting Antibiotic Resistance Selection on Novel Antimicrobial Coatings N2 - The global burden of antimicrobial resistance (AR) has manifested in an increasing number of deaths attributable to antibiotic-resistant bacteria (ARB) in recent years, with projections indicating a continued rise. Combating AR requires a multifaceted approach, one aspect of which involves preventing the spread of ARB in hospital environments via high-touch surfaces, which are known contributors to nosocomial infections. In conjunction with routine disinfection protocols and infection prevention measures, antimicrobial surfaces or antimicrobial coatings (AC) are increasingly being investigated and implemented to reduce microbial transmission via high-touch surfaces, thereby mitigating their spread in healthcare settings. However, similar to antibiotics, prolonged use of such surfaces may lead to the direct or indirect selection of ARB. To prevent this, targeted tests must be developed to predict potential AR selection before AC implementation. Materials and Methods As part of the Horizon-Europe-funded project "STOP" (Grant Agreement ID: 101057961), a novel antimicrobial coating is being developed and tested to reduce pathogen transfer on surfaces without selecting for ARB. To this end, two bacterial libraries (80 strains each) were assembled from the two species most associated with AR-attributable mortality worldwide, Escherichia coli and Staphylococcus aureus, as identified in the most recent comprehensive study [1]. Each library maintains a 50/50% ratio of strains resistant or sensitive to third-generation cephalosporins (E. coli) and methicillin (S. aureus), respectively—representing two of the most widespread resistance profiles. An adapted ISO 22196 method was developed using a reference benchmark antimicrobial surface (i.e., copper), with stainless steel serving as a control. The goal was to infer potential advantages of copper-unrelated antibiotic resistance phenotypes on the tested surface. Results Metadata, genomic data, and antibiotic susceptibility testing (AST) data were collected for all selected strains in each library, ensuring diversity in sequence types (ST) of clinical relevance, antibiotic resistance gene profiles, and geographical origins. The method was calibrated on copper surfaces using a reference E. coli strain, establishing the initial parameters required for investigators to customize the test for a given AC. Procedural reproducibility was assessed by comparing results from independent operators. Discussion The two libraries are currently being screened against the selected copper surfaces to identify potential associations between the resistance phenotypes of the tested species and their observed survival rates post-exposure. Three mutually exclusive outcomes are anticipated: (i) a statistically significant survival advantage of resistant strains compared to sensitive strains, (ii) an inverse scenario where sensitive strains exhibit higher survival, or (iii) no significant difference between the two groups. Furthermore, post hoc principal component analysis utilizing metadata and AST data may help elucidate genetic traits that confer a survival advantage on the tested AC. Conclusions This test aims to assist developers of antimicrobial coatings and materials in assessing potential selective pressures toward ARB before these products are implemented and evaluated under real-life conditions. T2 - ESB Conference CY - Torino, Italy DA - 07.09.2025 KW - Antimicrobial-resistance KW - Surface antimicrobial testing KW - Materials testing PY - 2025 AN - OPUS4-64569 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Marano, Roberto T1 - Antimicrobial coatings: modes of action, microbiological efficacy testing, and resistance evolution N2 - Within the Horizon-Europe funded project “STOP: Surface Transfer Of Pathogens”, Grant agreement 101057961, Working Package 6 is currently working on developing tests aimed at predicting possible selection and/or evolution of antibiotic resistance onto antimicrobial coatings meant for high-touch surfaces. This presentation describes the devised protocols and the preliminary results of their application on copper as a benchmark antimicrobial material. T2 - STOP-project Meeting CY - Sofia, Bulgaria DA - 27.02.2025 KW - Antimicrobial-resistance KW - Surface antimicrobial testing KW - Materials testing PY - 2025 AN - OPUS4-64567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -