TY - CONF A1 - Abilio, André T1 - Expert System for Screening Microbiologically Influenced Corrosion asInternal Failure Cause in Oil and Gas Upstream Pipelines N2 - The analysis of pipeline failures due to Microbiologically Influenced Corrosion (MIC) is challenging due to the complex interaction of many influencing parameters including pipeline operation conditions, fluid chemistry and microbiology, as well as the analysis of corrosion features and products. To help address this challenge, an expert system was developed to assist non-specialists in screening internal pipeline corrosion failures due to MIC related threats. To accomplish this, 15 MIC subject matter experts (with a total of 355 man-years of accumulated MIC based experience) were recruited to evaluate a total of 65 MIC failure cases based on real-life scenarios. These case study parameters and the expert elicited results were input into an Artificial Neural Network (ANN) model to create a model system which can screen whether a given failure scenario is one of three outcomes: a) failure is likely due to MIC, b) failure is likely not due to MIC, or c) the conclusion is inconclusive (analysis needs more data/information). The model system had an overall accuracy of 74.8%and it showcases that knowledge from subject matter experts can be captured in a reasonably effective way to screen for possible MIC failures. Based on that, this presentation will provide details of the model development process and key results to date. Important considerations regarding the level of confidence of the diagnoses and variation between expert opinion will also be discussed alongside with ideas on how to improve the model for field applicability. T2 - ISMOS 9 CY - Edinburgh, United Kingdom DA - 27.06.2023 KW - Expert System KW - Microbiologically Influenced Corrosion (MIC) KW - Oil and Gas Upstream KW - Artificial neural networks (ANNs) KW - Failure analysis PY - 2023 AN - OPUS4-64602 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Horn, Wolfgang T1 - Analytische Untersuchungen für Vitrinenbaumaterialien am Beispiel des BEMMA-Schemas N2 - BEMMA ist die Kurzbezeichnung für ein Verfahren zur Bewertung von Emissionen aus Materialien für Museumsausstattungen. Die Bewertung der Materialien erfolgt nach StAA-QMH-4.2-033. Mit diesem Verfahren lassen sich flüchtige organische Verbindungen aus modernen Werkstoffen, die in mittelbarem Kontakt mit historischen Materialien des Kunst- und Kulturgutes stehen, untersuchen und bewerten. Die Vitrinenbaumaterialien, nicht die Vitrine, werden im Hinblick auf ihre Emissionen bewertet. Die Ergebnisse der Messungen werden auch vor dem Hintergrund von realen Vitrinenmessungen eingeordnet und die Herausforderungen bei der Probenahme dargestellt. T2 - Klima- und Schadstoffmanagement in der passiven Vitrine Aktuelle Forschungsergebnisse CY - Berlin, Germany DA - 13.10.2025 KW - Emission KW - BEMMA KW - Vitrinen KW - VOC PY - 2025 AN - OPUS4-64529 LA - deu 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 - CONF A1 - An, Biwen Annie T1 - Standardization of MIC laboratory testing: with a special focus on corrosive methanogens N2 - Microbiologically influenced corrosion (MIC) is a highly unpredictable process involving a complex group of microorganisms, including sulfate-reducing bacteria and methanogens. Standard laboratory MIC testing using static serum bottle enrichments is an easy but limited method, offering poor resolution on the biomineralization process of corrosion products. An example of this is the presumed corrosion product siderite by corrosive methanogens (Mi-MIC). Previous publications reported siderite was the sole corrosion product of M. maripaludis using metal coupons incubated under stationary conditions. However, the formation of siderite is closely related to the surrounding environmental conditions, i.e. pH, CO2 concentration, flow and temperature. Thus, siderite as the sole corrosion product of Mi-MIC remain inconclusive and questionable. To study Mi-MIC effectively, a novel versatile multiport flow-column corrosion monitoring system (MFC) was developed. MFC allows sectional corrosion rate determination under flow conditions using different types of material, inoculum and packing material. MFC offers great flexibility, ease of operation and accurate corrosion measurements that can be combined with many other techniques. Using MFC, we studied multiple strains of methanogens and compared it with sulfate-reducing bacteria under neutral and low pH conditions. It was revealed by MFC that corrosive methanogens have equally high corrosion potential as sulfate-reducing bacteria. Additionally, siderite is not the dominant nor sole corrosion product of Mi-MIC. Thus, effective corrosion monitoring and establishing standard laboratory practices, i.e. incorporating MFC as part of regular testing process, will provide deeper understanding of MIC. This will allow further microbial electrophysiology understandings, contributing to effective mitigation strategy development. T2 - EUROPEAN MIC NETWORK WEBINAR CY - Online meeting DA - 19.05.2020 KW - MIC KW - Methanogen KW - FIB/SEM KW - Corrosion products KW - Microbiologically influenced corrosion KW - Flow Model KW - Modelling KW - Korrosion PY - 2020 AN - OPUS4-51554 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 - Misra, Archismita T1 - Polyoxometalate Ionic Liquids (POM-ILs) as Protective Coatings for CulturalHeritage against Acid Corrosion and Biodeterioration N2 - Corrosion of stone by acid rain anddeterioration from microbial biofilmsare challenges pertinent worldwide forindustrial or residential buildings as wellas cultural heritage artefacts, like statuesor historic buildings. One mitigationoption might be the use of thintransparent films of polyoxometalate-based ionic liquids (POM-ILs). In thisregard, different limestone samples werecoated with hydrophobic, acid resistantPOM-ILs which also have biocidalproperties.1 Exposure of the samples tosimulated acid rain showed negligiblecorrosion compared to the significantdeterioration of unprotected samples(Fig 1. Left). In addition, the biocidalproperties of the POM-ILs suppress theformation of biofilms on coated stoneslabs. The coating is mechanically stableand is not removed even by harshmechanical and chemical treatment.Following studies successfully exploredthe effectiveness of the coating againstlampenflora growing in the PommeryChampagne cellar 2 (Fig 1. Right); andthe long-term performance of POM-ILsunder outdoor environmental conditions3. So, POM-ILs are already proven topossess remarkable anticorrosion andantimicrobial properties against aerobicmicroorganisms and being water-insoluble, they don’t get leached intoaquatic ecosystem, which is extremelybeneficial from an environmentalsustainability and toxicological point ofview. The current project aims tocontinue the journey on protecting thecultural heritage, shifting focus fromstones to metals and employ functionalPOM-IL nanocoatings to prevent MIC(Microbiologically Influenced Corrosion)of cultural heritage artefacts made ofmetal or metal alloy like carbon steel,brass, cast iron or bronze. Performanceof both the coating materials and coatingtechniques via optimization of theadhesion of the nanocoating on themetallic surface on the corrosion rateand corrosion products in the MICcaused by anaerobic microorganismslike methanogenic archaea or SulphateReducing Bacteria (SRB) would betested. The objective is to establishPOM-ILs as efficient environmentallysustainable nanocoating materialsagainst biocorrosion citing the already published success stories; and sketch theongoing endeavours and prospects ofthese very efficient candidates in thecontext of MIC mitigation. T2 - Mitigation of Microbiologically InfluencedCorrosion: Towards Scientific &Industrial Standardization (MIC-STAND) CY - Lisbon, Portugal DA - 24.07.2024 KW - Microbiologically influenced corrosion (MIC) KW - Polyoxometalate Ionic Liquid KW - Nanocoating KW - Cultural heritage PY - 2024 AN - OPUS4-64575 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Misra, Archismita T1 - Polyoxometalate Ionic Liquids (POMILs) as Protective Coatings for Cultural Heritage Against Acid Corrosion and Biodeterioration N2 - Corrosion of stone by acid rain anddeterioration from microbial biofilms are challenges worldwide present forindustrial or residential buildings as wellas cultural heritage, like statues orhistoric buildings. One option is the useof thin transparent films ofpolyoxometalate-based ionic liquids(POM-ILs). Stone samples were coatedwith hydrophobic, acid resistant POM-ILs which also have biocidal properties.1Exposure of the samples to simulatedacid rain showed negligible corrosioncompared to the significant deteriorationof unprotected samples (Fig 1. Left). Inaddition, the biocidal properties of thePOM-ILs suppress the formation ofbiofilms on coated stone slabs. Thecoating is mechanically stable and is notremoved even by harsh mechanical andchemical treatment. Following studiessuccessfully explored the effectiveness ofthe coating against lampenflora growingin the Pommery Champagne cellar 2 (Fig1. Right); and the long-termperformance of POM-ILs under outdoorenvironmental conditions 3. So, POM-ILs are already proven to possessremarkable anticorrosion andantimicrobial properties against aerobicmicroorganisms and being water-insoluble, they don’t get leached intoaquatic ecosystem, which is extremelybeneficial from an environmentalsustainability and toxicological point ofview. The current project aims tocontinue the journey on protecting thecultural heritage, shifting focus fromstones to metals and employ functionalPOM-IL nanocoatings to prevent MIC(Microbiologically Influenced Corrosion)of cultural heritage artefacts made ofmetal or metal alloy like carbon steel,brass, cast iron or bronze. Performanceof both the coating materials and coatingtechniques via optimization of theadhesion of the nanocoating on themetallic surface on the corrosion rateand corrosion products in the MICcaused by anaerobic microorganismslike methanogenic archaea or SulphateReducing Bacteria (SRB) would betested. The objective would be toestablish POM-ILs as efficientenvironmentally sustainablenanocoating materials againstbiocorrosion citing the already publishedsuccess stories; and sketch the ongoingendeavours and prospects of these veryefficient candidates in the context ofbiocorrosion T2 - International Biodeterioration and Biodegradation Symposium CY - Berlin, Germany DA - 09.09.2024 KW - Microbiologically influenced corrosion (MIC) KW - Polyoxometalate Ionic Liquid KW - Nanocoating KW - Cultural heritage PY - 2024 AN - OPUS4-64576 LA - eng 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 - Bresch, Harald T1 - Nanoparticle Characterisation - The long way to standardisation N2 - Diese Präsentation gibt einen Überblick über die Entwicklung der Nanopartikelforschung von ca. 2005 bis heute. Beginnend mit den Besonderheiten von Nanopartikeln und der Aufnahme in den menschlichen Körper über Messmethoden bis hin zur Entwicklung einer Prüfrichtlinie im Rahmen der OECD und einem Ausblick über die absehbaren digitalen Entwicklungen. T2 - Abteilungsseminar der Abteilung 4 CY - Berlin, Germany DA - 27.02.2025 KW - Nanomaterials KW - Nano KW - OECD KW - Standardisierung KW - Advanced Materials PY - 2025 AN - OPUS4-64977 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rabin, Ira T1 - Tintencharakterisierung: Optische Eigenschaften und elementare Zusammensetzung N2 - Die Präsentation beschreibt alle Typen der schwarzen Schreibmaterialien, die in der Antike und Mittelalter benutzt wurden. Weiterhin wir das bei der BAM entwickelte Untersuchungsprotokoll präsentiert, das aus zwei Stufen besteht: a) der Feststellung des Tintentyps anhand der optischen Eigenschaften; die Ausrechnung von den Fingerprints der Eisengallustinten anhand der elementaren Zusammensetzung. Die Arbeit wird durch Fallbeispiele illustriert. T2 - Schriftkulturen des Mittelalters in digitaler Perspektive CY - Berlin, Germany DA - 22.08.2025 KW - Tinte KW - Tusche PY - 2025 AN - OPUS4-64775 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rabin, Ira T1 - The Temple Scroll: Reconstructing an Ancient Manufacturing Practice N2 - The presentation shows the studies of ancient parchment and leather conducted by the authors within last 20 years. Presentation specifically focusses on poduction of the parchment of the Temple scroll. The practice unites the early production of modern parchment with the lost way of skin splitting. T2 - The Temple Scroll: A Research Colloquium CY - New York City, USA DA - 24.02.2025 KW - Dead Sea Scrolls KW - Parchment KW - Tanning PY - 2025 AN - OPUS4-64779 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bresch, Harald T1 - The digital product passport N2 - This presentation contains information for industry and the scientific communitiy about the new digital product passport and the demands from the EU. Furthermore a short overview is given about the different supporting activities which are currently under developement by BAM. T2 - 3. Netzwerktag Cluster Nanotechnologie CY - Würzburg, Germany DA - 02.07.2025 KW - DPP KW - ESPR KW - Product Passport KW - Ökodesignrichtlinie KW - DMP PY - 2025 AN - OPUS4-64964 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kalbe, Ute T1 - Elutionsverfahren in Forschung und regulatorischem Kontext N2 - Elutionsverfahren sind ein Tool für Umweltverträglichkeitsprüfungen verschiedenster Materialien im Kontakt mit Wasser. Im früheren Fachbereich 4.3 Schadstofftransfer und Umwelttechnologien wurden dazu umfangreiche Kompetenzen vor allem im Zusammenhang mit mineralischen Reststoffen sowie vielfältigen Bauprodukten aufgebaut und experimentelle Erfahrungen gesammelt. Darüber hinaus wurde auch der Austrag von Partikeln betrachtet und die gleichzeitige Bewertung von Mikroplastik- und Schadstoffausträgen aus Kunsstofftrasen untersucht. Es sind aber auch weitere Anwendungen beispielsweise zur Prüfung der Beständigkeit von Materialien denkbar. Im Workshop wurden Anwendungsbereiche von Elutionsverfahren diskutiert mit dem Ziel der besseren Vernetzung, der gemeinsamen Nutzung von Ressourcen und Identifikation von Synergien zwischen den Fachbereichen bzw. Aktivitätsfeldern. T2 - Workshop - Bewertung der Freisetzung von (Schad)stoffen aus Materialien mit Elutionsverfahren CY - Berlin, Germany DA - 21.01.2025 KW - Elution KW - Materialien KW - Schadstoffe PY - 2025 AN - OPUS4-65023 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Julseth, Mara Jean T1 - Dynamics of Chromosome Evolution in Reticulitermes of Europe N2 - Termites challenge long-standing assumptions about insect social evolution. One important difference compared to the social ants, bees and wasps lies in their chromosomes: termites are diploid, with X/Y sex differentiation observed in most species and males playing active roles across all castes and life stages. Adding to their uniqueness, termites exhibit multivalent chromosome chains during male meiosis—an intriguing and seldom seen feature of eukaryote evolution. These chains, in addition to other chromosomal formations, such as bivalent rings and rods, may serve to suppress recombination, thereby mitigating against the potentially harmful effects of inbreeding. Multivalent chromosome chains may also play a significant role in speciation processes by increasing the likelihood of chromosomal translocations and promoting genomic islands of divergence. In European Reticulitermes, variability in chain length and stability both between and within species provides a compelling model system for studying the evolutionary importance of multivalent chromosome chains at intra- and interspecific levels and at different evolutionary time scales. To investigate these dynamics, we collected over 200 colonies of Reticulitermes species across the Mediterranean, generating de novo reference genomes, comprehensive population genomic as well as karyotypic data from three recently diverged species. Our findings shed light on the intricate relationship between chromosomal architecture and evolutionary mechanisms in termites, offering new insight into how genome structure shapes species evolution T2 - Gevol SPP Meeting 2025 CY - Münster, Germany DA - 04.09.2025 KW - Termites KW - Chromosome evolution PY - 2025 AN - OPUS4-65060 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schreiber, Frank T1 - Biocide Resistance - Road to Risk Assessment N2 - This presentation details the current status of biocide resistance risk assessment and provides a roadmap for future activities. T2 - OECD, 6th Meeting of the Working Party on Biocides CY - Paris, France DA - 28.09.2022 KW - Antimicrobial resistance KW - Antimicrobial coating KW - Standardization KW - Biocides KW - Risk assessment PY - 2022 AN - OPUS4-56263 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sobisch, Lydia-Yasmin T1 - Identification of Genes Involved in Susceptibility to Biocides in Sulfate-Reducing Bacteria N2 - Microbially induced corrosion (MIC) poses a significant challenge in various industries, leading to structural damage and economic losses due to the activity of microorganisms on metal surfaces. The major culprits of MIC are the sulfate-reducing bacteria (SRB). A common mitigation method is the usage of biocides to prevent MIC. However, the molecular mechanisms that determine susceptibility of SRB to biocides have been poorly understood. Our aim is to identify genes that are linked to biocide susceptibility in the model SRB strain Oleidesulfovibrio alaskensis (G20). We investigated the susceptibility of G20 towards three biocides commonly used in MIC protection: benzalkonium chloride (BAC), glutaraldehyde (GTA), and tetrakishydroxymethyl phosphonium sulphate (THPS). We determined selection of mutants in specific genes in two G20 barcoded transposon mutant libraries in the presence of these biocides and media as control along a concentration gradient up to 500 ppm. Our study investigated over 1843 genes in G20, revealing insights into their response to biocide treatments. We identified 1668 genes negatively affected by biocide treatment, while 175 genes showed improved fitness. Among the treatments leading to reduced fitness in the mutants, GTA had the highest number of solely negatively affected genes (186), followed by BAC (67) and THPS (69). There were common negative impacts on 280 genes of all four treatments (BAC, GTA, THPS, control). Notably, BAC and GTA shared 113 affected genes, BAC and THPS shared 59, and GTA and THPS shared 72. On the single gene level, mutants treated with THPS exhibited reduced fitness for the rluD gene (DDE_1447), encoding ribosomal large subunit pseudouridine synthase d, which plays a crucial role in protein biosynthesis. In the presence of BAC, mutants showed reduced fitness due to the lack of the acrB gene (DDE_0401), encoding a cationic efflux pump crucial for biocide resistance. Our findings provide leads for future research into the detailed molecular mechanisms that underlie biocide susceptibility in microorganisms responsible for MIC. Such detailed understanding will enable the development of improved MIC prevention strategies and foster a more sustainable use of biocides. T2 - International Biodeterioration and Biodegradation Symposium CY - Berlin, Germany DA - 09.09.2024 KW - Biocide Resistance KW - Transposon Mutant Libraries KW - Sulfate-Reducing Bacteria (SRB) KW - Microbially Induced Corrosion (MIC) PY - 2024 AN - OPUS4-61526 LA - deu 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 - Schreiber, Frank T1 - Die Entstehung von antimikrobiellen Resistenzen durch die Verwendung von Bioziden N2 - Dieser Vortrag gibt einen Überblick über die BAM und die Aktivitäten im Bereich Biozidresistenz. T2 - Berliner Hochschule für Technik Studiengang Biotechnologie CY - Berlin, Germany DA - 05.05.2023 KW - Antimikrobielle Resistenz KW - Antmikrobielle Oberflächen KW - Standardisierung PY - 2023 AN - OPUS4-57859 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schreiber, Frank T1 - How to regulate and assess resistance risks of co-selecting agents during application and in the environment N2 - This talk deals with the question on How to regulate and assess resistance risks of co-selecting agents during application and in the environment. It shows that there the overview of worldwide activities to regulate co-selecting agents is missing. Regulations for product authorization usually consider resistance in target organisms, but there is a risk of emergence of resistance from non-target organisms as well. Moreover, pollution effects on resistance development in the environment are not explicitly covered during product authorization and few risk assessment schemes and methods available. T2 - EDAR7 - Environmental Dimension of Antimicrobial Resistance Conference 2024 CY - Montreal, Canada DA - 26.05.2024 KW - Antimicrobial resistance KW - Bacteria KW - Standardization KW - Biocides PY - 2024 AN - OPUS4-61542 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 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 -