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 - Olbrich, Adelina-Elisa T1 - Deciphering microbiological influenced corrosion processes on steel with single cell-ICP-ToF-MS N2 - Microbiologically influenced corrosion (MIC) is a highly unpredictable process dictated by the environment, microorganisms, and the respective electron source. Interaction pathways between cells and the metal surface remain unclear. The development of this novel single cell-inductively coupled plasma-time of flight-mass spectrometry analytical method and a MIC-specific staining procedure facilitate the investigation of steel-MIC interactions. With this it is possible to analyze the multi-elemental fingerprint of individual cells. The detection method revealed elemental selectivity for the corrosive methanogenic archaeal strain Methanobacterium-affiliated IM1. The interface between material and environmental analysis thus receives special attention, e.g., when considering MIC on solid steel. Hence, the possible uptake of individual elements from different steel samples is investigated. Results showed the cells responded at a single-cell level to the different types of supplemented elements and displayed the abilities to interact with chromium, vanadium, titanium, cobalt, and molybdenum from solid metal surfaces. 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 research. References. T2 - Future WiNS CY - Berlin, Germany DA - 07.12.2022 KW - Single cell KW - Microbiological influenced corrosion MIC KW - Sc-ICP-ToF-MS KW - Method development KW - Ir DNA staining approach KW - Carbon steel corrosion PY - 2022 AN - OPUS4-56567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Martens, Birte T1 - The evolution of symbiont and immune system interactions in Blattodea N2 - Immunity plays an important role in evolutionary ecology. The immune system interacts with both pathogens, which can act as important selective forces, and symbionts, which are regulated by the host‘s immune system and can also play a role in the host‘s immune defenses. The Blattodea consist of what is commonly known as cockroaches and the termites, who are themselves specialized eusocial cockroaches. Blattodea have two symbiont types that are characteristic to either the cockroaches or the termites (Table 1). These symbiont transitions open up the opportunity to characterize and investigate host-symbiont-pathogen interactions and how they evolved in Blattodea. T2 - Ecological Immunology Workshop 2025 CY - Joachimsthal, Germany DA - 15.09.2025 KW - Evolution KW - Cockroaches KW - Immunity KW - Symbionts KW - Host-Symbiont-Interactions PY - 2025 AN - OPUS4-64971 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Martens, Birte T1 - The evolution of symbiont and immune system interactions in Blattodea N2 - Immunity plays an important role in evolutionary ecology. The immune system interacts with both pathogens, which can act as important selective forces, and symbionts, which are regulated by the host‘s immune system and also can play a role in the host‘s immune defenses. The Blattodea consist of what is commonly known as cockroaches and the termites, who are themselves specialized eusocial cockroaches. Blattodea have two symbiont types that are characteristic to either the cockroaches or the termites (Table 1). These symbiont transitions open up the opportunity to characterize and investigate host-symbiont-pathogen interactions and how they evolved in Blattodea. T2 - Insect Infect Meeting 2025 CY - Berlin, Germany DA - 07.04.2025 KW - Evolution KW - Cockroaches KW - Immunity KW - Symbionts KW - Host-Symbiont-Interactions PY - 2025 AN - OPUS4-64970 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fuentes, Elsa A1 - Prieto, Beatriz A1 - Gorbushina, Anna T1 - Mixed model biofilm: interactions between algae, fungi and cyanobacteria and their effects on granite biodeterioration N2 - Granite, despite being one of the most widely used rocks for building material cultural heritage, is also one of the least studied. Previous works have shown that environmental parameters modulated by climate change will lead to changes in the microbial composition of biofilms grown on stone, but also to changes in the production of EPS, in the composition of pigments and, as a consequence, in the biodeterioration processes that this rock undergoes (Fuentes, 2023). Considering that the colonisation process is highly dynamic, small changes in climatic conditions can lead to the formation of different types of biofilms and diverse interactions between species. Knowing the contribution of the different organisms to the deterioration process is important both to anticipate the consequences that climate change will have on the deterioration of the granite, but also when addressing the processes of recolonization after cleaning, to ensure an improvement of the present situation. So, in order to continue my line of research on granite biodeterioration, the aim of this new project is to study the contribution of each type of organism (green algae, cyanobacteria and fungi) to the process of granite deterioration as well as the specific effect on each mineral, in addition to its role in the resilience and response of biofilms to environmental changes. With this main objective, the effect of the type of substrate on the composition of a model mixed biofilm formed by the fungus Knufia petricola, the algae Jaagichlorella sp. and the cyanobacterium Synechocystis sp. will be studied. The results obtained on granite will be compared with those obtained with other lithic types such as marble or limestone. Furthermore, it will be observed if the different ratios between organisms lead to changes in the capacity of these organisms to generate biodeterioration and to buffer climatic changes. Finally, the susceptibility of each mineral that makes up the granite - quartz, feldspars, micas - to biodeterioration mediated by each type of organism will be analysed. To address these questions, on the one hand, the response of the mixed biofilms as a whole will be evaluated by means of confocal microscopy, PAM, as well as the quantification of pigments and EPS, and on the other hand, the effect of these organisms on the deterioration of the substrates, through the use of SEM and TEM, which will allow the assessment of both the changes in porosity and the appearance of deterioration in the surface layers of the rock. This research will deepen the knowledge of the processes of granite deterioration, which have been limitedly studied in relation to microorganisms; but also aims to provide the scientific community with a model mixed biofilm to increase the reproducibility between experiments, one of the main limitations of this field of study. T2 - 19th International Biodeterioration and Biodegradation Symposium CY - Berlin, Germany DA - 09.09.2024 KW - Biofilm KW - Stone KW - Algae KW - Fungi KW - Cyanobacteria KW - Cultural heritage PY - 2024 AN - OPUS4-62272 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - 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 - Gerrits, Ruben T1 - Genetic engineering of a black rock-inhabiting fungus shows its strengths and weaknesses  N2 - Environmental black fungi are known to inhabit anthropogenic habitats like marble monuments, solar panels, indoor walls and even washing machines. These pests are generally assumed to persist and grow in these environments due to their melanin production and oligotrophic lifestyle, respectively. We aimed to confirm these assumptions and to find methods to mitigate their substrate colonisation and deterioration by looking at their ability to produce melanin and take up iron, the latter being a general weakness of aerobes. This was done by means of selecting one species, Knufia petricola, and applying CRISPR/Cas9-mediated genome editing techniques. This showed that K. petricola produces one siderophore; deletion of its encoding gene showing no strong phenotypic effects. Deletion of the other iron uptake mechanism – reductive iron assimilation (RIA) – did however cause a strong growth deficiency at iron depleted conditions. Both together reveal that K. petricola has a weak siderophore and relies on RIA to acquire iron, reflecting a natural habitat free of competition for iron. This comes at a price: K. petricola but also other black fungi isolated from solar panels are extremely sensitive to mediocre iron chelators, offering us a mitigation strategy. Melanin, although adsorbing and reducing iron, did not have an observable effect on iron uptake. The pigment did however affect the fungal ability to withstand desiccation: pigment-deficient mutants were not able to withstand a prolonged incubation in a desiccator. This is a clear advantage in the colonisation of dry subaerial surfaces. T2 - 12th International Mycological Congress (IMC12) CY - Maastricht, Netherlands DA - 12.08.2024 KW - Iron uptake KW - Black fungi KW - Melanin PY - 2024 AN - OPUS4-62269 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Catanzaro, Ilaria T1 - Understanding the role of DHN melanin in Cryomyces antarcticus N2 - Cryomyces antarcticus – a cryptoendolithic black fungus endemic to Antarctica – is taxonomically classified in phylum Ascomycota, class Dothideomycetes incertae sedis. C. antarcticus has shown high capability to survive extreme environmental conditions like those found in space (ionizing radiation, vacuum, microgravity), thus fueling fundamental astrobiological questions like “searching for life beyond Earth” (Onofri et al. 2020, Extremophiles Astrobiol Model). Its extraordinary resilience has been attributed to the presence of thick, highly melanized cell walls, which may contain both DHN and DOPA melanins (Pacelli et al. 2020, Appl Microbiol Biotechnol). To better understand the contribution of DHN melanin to the overall resilience of C. antarcticus, we initially adopted chemicals e.g., tricyclazole to inhibit the DHN melanin synthetic pathway; however, these studies gave inconclusive results. Eventually, we decided to generate melanin-deficient mutants by genetic engineering. Using the genetic toolkit developed for the black fungus Knufia petricola (Voigt et al. 2020, Sci Rep; Erdmann et al. 2022, Front Fungal Biol), we designed a strategy for mutating the key enzyme (polyketide synthase)-encoding gene capks1 by transient delivery of Cas9 and capks1-specific sgRNA from AMA-containing plasmids and PCR-generated donor DNA i.e., resistance cassettes flanked by ~75-bp-long sequences homologous to capks1. For this, the melanin-PKS encoding ortholog was identified in the C. antarcticus CBS 116301 genome (mycocosm.jgi.doe.gov) and used to design primers for re-sequencing of the capks1 locus in the strain CCFEE 515. Transformation of C. antarcticus is challenging because of its very slow growth; we expect that 4-6 months are needed from obtaining enough biomass for cell wall lysis until transferring putatively resistant transformants for genotyping. Important parameters were evaluated: protoplasts can be generated, and they survive the transformation procedure, and suitable concentrations of selective agents have been identified. Nowadays, we are waiting for the first C. antarcticus mutants considered to be deficient in DHN melanogenesis. T2 - 16th European Conference on Fungal Genetics CY - Innsbruck, Austria DA - 05.03.2023 KW - Cryptoendolithic black fungus KW - DHN melanin KW - Astrobiology PY - 2023 AN - OPUS4-57145 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Raedel, Martina T1 - Conservation of damaged architectural aluminum elements N2 - Aluminum is an often-used building material in modern architecture. In recent years buildings from the 1950th and 1960th are increasingly subject of conservation works including the aluminum parts. Typical surface damages are signs of corrosion caused by weathering processes or scratches in the anodized layer due to extensive wear. To repair damaged aluminum surfaces, there are usually two options: smaller areas are repaired by using a touch-up pen, for larger damages it is necessary to remove the anodized layer completely. Both possibilities are disadvantageous for the objects; the touch-up pen often does not match the color together with an insufficient corrosion protection, while newly anodized layers often differ in color and gloss from the original surface. For this reason, a research project was initiated to develop a mobile method to repair anodized aluminum parts. The first step focusses on the mobile anodization process by using the electrolyte with a gel substrate. Different cathodic materials are to be tested together with appropriate cooling material. The anodized area should be isolated to protect undamaged areas. Examinations of the produced layers are conducted by using Keyence microscope, eddy current testing and ESEM analysis. Further steps are to transform the coloring and sealing process for mobile application. Color could be applied by using a brush or by spray while the sealing process could be performed with water vapor. An heatable putty knife could be used, if heating up the area will be necessary. Once the application process is developed, the anodization will be tested on samples with artificial damages, fixed in horizontal and vertical positions. The stability of the anodized surface will be examined by accelerated ageing in a climate chamber and outdoor weathering. The electrolyte (diluted sulfuric acid) was combined with a gel binder to enable a mobile application. Several thickening agents were tested concerning their conductivity and stability in acid systems. Anodization tests with different cathodic material and shapes were conducted. The temperature during anodization was controlled and adjusted if necessary. The anodized area was restricted by using either a lacquer, an adhesive or a removable silicon barrier. The fist results show the feasibility of the method on enclosed areas. The achieved thickness was measured by eddy current testing and the structure was controlled by ESEM analysis. The examinations show a connection between thickness and porosity of the anodized layers and the temperature during the application process. Next steps are testing mobile coloring and sealing methods followed by mobile anodization on artificial damaged areas. T2 - Metal 2019 CY - Neuchâtel, Switzerland DA - 02.09.2019 KW - Mobile anodisation KW - Aluminium KW - Conservation KW - Damage repair PY - 2020 UR - https://www.lulu.com/shop/claudia-chemello-and-laura-brambilla-and-edith-joseph/metal-2019-proceedings-of-the-interim-meeting-of-the-icom-cc-metals-working-group-september-2-6-2019-neuch%C3%A2tel-switzerland-ebook/ebook/product-24517161.html AN - OPUS4-51479 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gorbushina, Anna T1 - From rocks to riches: Knufia petricola as model and expression platform N2 - Black fungi belong to different classes of Ascomycota but evolved similar morpho-physiological adaptations such as yeast-like growth and constitutive melanin formation to colonize extreme competition-free environments. They are ubiquitously found on air-exposed surfaces, from ancient marble monuments to modern solar panels. The rock inhabitant Knufia petricola was chosen to become a model for these extremotolerant black fungi. Plasmid-based and ribonucleoprotein-based CRISPR/Cas9 techniques were introduced to precisely introduce one to multiple double strand breaks into the DNA to modify, replace or add sequences to the genome either using the available selection marker systems (hygR, natR, genR, baR, suR) or by marker-free approaches. Multiplexing is very efficient, allowing for four or more simultaneous genome editing events. The newly generated cloning vectors containing the Tet on construct for doxycycline-controlled gene expression, and the validated sites in the K. petricola genome for color-selectable (pks1, phs1, ade2) or neutral insertion (igr1 to 5) of expression constructs complete the reverse genetics toolbox. One or multiple endogenous or heterologous genes can be expressed on demand from different genomic loci or from a single construct by using 2A self-cleaving peptides. We thus can express genes from synthetic clusters in a non-pigmented background (Δpks1/Δphs1). The fact that K. petricola only produces few secondary metabolites (DHN melanin, carotenoids, mycosporines and a siderophore) and plant cell-wall degrading enzymes but is capable to take the burden of acetyl-CoA-consuming metabolism and protein secretion renders K. petricola a promising host for the expression of heterologous genes encoding high-end secondary metabolites and enzymes. T2 - 12th International Mycological Congress (IMC12) CY - Maastricht, Netherlands DA - 11.08.2024 KW - Fungus KW - Genetic engineering KW - Heterologous gene expression KW - Cell factory PY - 2024 AN - OPUS4-60838 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gorbushina, Anna T1 - A genetic toolbox for exploring the life style of the rock-inhabiting black fungus Knufia petricola N2 - After their discovery on rock surfaces in cold and hot deserts, a polyphyletic group of ascomycetous black fungi was found to dominate a range of hostile environments – natural and man-made, from salterns to dishwashers, roofs and solar panels. Together with bacteria and algae they may establish subaerial biofilms and cause weathering of the surfaces they grow on. Their impressive survival abilities as well as their constitutive protective pigmentation and cluster-like microcolony organisation are similar in environmental isolates as well as in heat-tolerant opportunistic pathogens of animals and humans. The exact genetic properties that ensure their survival in extreme environments can be studied if some black fungi were amenable to genetic manipulations. We selected the rock-inhabiting fungus Knufia petricola (class Eurotiomycetes, order Chaetothyriales) that grows moderately in axenic culture and exhibits all the characteristics of microcolonial black fungi such as yeast-like cell growth, absence of reproductive structures and constitutive dihydroxynaphthalene (DHN) melanogenesis (Nai et al. 2013, Fungal Genet Biol). We developed protocols to efficiently generate and transform protoplasts resulting in stable homokaryotic transformants by targeting genes involved in pigment synthesis and expressing fluorescent reporter genes. Hence, endogenous and foreign genes can be expressed from episomal AMA1-containing plasmids and genome-integrated DNA constructs. Moderate rates of homologous recombination allow for both ectopic and targeted integrations. CRISPR-Cas9 was further validated as a strategy for obtaining selection marker-free mutants and silencing via RNA interference as an approach to study essential genes. Availability of this genetic toolbox and an annotated genome sequence of the strain A95 is paving the way for studying interactions of K. petricola with environmental stressors, material surfaces, soil matrices and phototrophic symbionts. T2 - European Conference on Fungal Genetics (ECFG15) CY - Rome, Italy DA - 17.02.2020 KW - black fungi KW - genomics KW - genetics PY - 2020 AN - OPUS4-50593 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Davenport, Rebecca T1 - Regulations versus practice and the Divine Name: Ink analysis in medieval Torah scrolls N2 - The medieval Rabbis had very strict rules for the construction of a Sefer Torah. The Divine Names should be written • by a qualified scribe • who is ritually pure • in the presence of a minyan (10 adult Jewish men) • in an appropriate frame of mind • without being interrupted However, when these scrolls were written it would have been impossible to verify any of this after the fact. While we do not currently have any way to determine how recently the scribes had bathed, or what they might have been thinking as they wrote, we can now know much more about the inscription of the Divine Name than these scribes ever would have guessed. It is sometimes apparent from a visual inspection of the text that the Divine Name has been written in a second stage, from irregular letter kerning or a different ink colour. Using XRF, we have been able to discover more instances of a different ink used for the Name, and have shown that in some cases the secondary ink was also used to correct the main text, suggesting that the later writing was done by a master scribe who also proofread the entire scroll. Using a Brucker M6 Jetstream, it has been possible to produce elemental “heat maps” of whole paragraphs or even large sections of a parchment sheet. Using such large samples of text, we can usefully compare the levels of copper and zinc used to write individual letters or words despite their relatively low concentration, which permits very fine differentiation of the inks used. The techniques presented here would also be highly applicable to assessing ink degradation, as they are able to detect much smaller differences in ink composition than had previously been possible. T2 - The International Iron Gall Ink Meeting 2025 CY - Lisboa, Portugal DA - 07.05.2025 KW - XRF spectroscopy KW - Torah scrolls KW - Jewish studies KW - XRF mapping PY - 2025 AN - OPUS4-65036 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Julseth, Mara Jean T1 - Multivalent Myteries: How Termite Chromosome Chains Shape Evolution N2 - Termites challenge long-standing assumptions about insect social evolution. One important difference compared to the social ants, bees and wasps lies in their chromosomes: termites are diploid, with X/Y sex differentiation observed in most species and males playing active roles across all castes and life stages. Adding to their uniqueness, termites exhibit multivalent chromosome chains during male meiosis—an intriguing and seldom seen feature of eukaryote evolution. These chains, in addition to other chromosomal formations, such as bivalent rings and rods, may serve to suppress recombination, thereby mitigating against the potentially harmful effects of inbreeding. Again, this positions termites as an important contrasting study system to other social insect groups, where recombination rates tend to be elevated. Multivalent chromosome chains may also play a significant role in speciation processes by increasing the likelihood of chromosomal translocations and promoting genomic islands of divergence. In European Reticulitermes, variability in chain length and stability both between and within species provides a compelling model system for studying the evolutionary importance of multivalent chromosome chains at intra- and interspecific levels and at different evolutionary time scales. To investigate these dynamics, we collected over 200 colonies of Reticulitermes species across the Mediterranean, generating de novo reference genomes, comprehensive population genomic as well as karyotypic data from three recently diverged species. Our findings shed light on the intricate relationship between chromosomal architecture and evolutionary mechanisms in termites, offering new insight into how genome structure shapes species evolution. T2 - ESEB 2025 Congress CY - Barcelona, Spain DA - 17.08.2025 KW - Termites KW - Chromosome evolution PY - 2025 AN - OPUS4-65059 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - 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 - Schulz, Anne-Christine T1 - Co-selection for biocide and antibiotic resistance in microbial wastewater communities N2 - Biocides are used for a wide range of purposes, including disinfectants or preservatives. They play a major role in the prevention of microbial infections in healthcare and animal husbandry. The use of biocides often leads to the discharge of active biocidal substances into wastewater streams, causing the exposure of wastewater microbial communities to subinhibitory concentrations. In turn, it is known that wastewater treatment plants (WWTP) are hotspots for antibiotic resistant bacteria. Since similar mechanisms confer resistance to biocides and antibiotics, exposure to biocides can result in co-selection of antibiotic resistant bacteria in WWTP Here, we want to investigate co-selection processes of antibiotic resistance in natural WWTP microbial communities upon biocide exposure. Microbial communities were sampled at the WWTP Ruhleben in Berlin and characterized regarding their susceptibility against different clinically relevant antibiotics. To investigate the link between biocide exposure and antibiotic resistance, changes in the susceptibility level after exposure to environmentally relevant concentrations of the commonly used biocide didecyldimethylammonium chloride (DDAC) will be determined by enumerating resistant and non-resistant E. coli on selective plates with and without antibiotics and DDAC. In case of antibiotics, clinical breakpoint concentrations according to EUCAST will be used to discriminate between susceptible and resistant strains. In case of DDAC (and biocides in general), clinical breakpoints do not exist. Therefore, we determined a cut-off concentration at which the majority of naturally-occurring E. coli strains cannot grow anymore based on (I) the MIC (minimal inhibitory concentration) distribution, and (II) by plating wastewater communities onto selective indicator agar plates loaded with increasing DDAC concentration. Additionally, antibiotic cross-resistance will be determined by spotting single colonies, isolated from DDAC-selective plates onto antibiotic plates. The results of our experiments will help to determine selective concentrations and to estimate the risk of antibiotic co-selection and cross-resistance in microbial WWTP communities upon biocide exposure. T2 - Annual Conference 2023 of the Association for General and Applied Microbiology CY - Göttingen, Germany DA - 10.09.2023 KW - Antibiotic resisitance KW - Biocide KW - Wastewater KW - Risk assesment PY - 2023 AN - OPUS4-58510 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - 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 - Dehkohneh, Abolfazl T1 - Effect of Carbon and Nitrogen on Growth of the Oligotrophic and Extremotolerant Fungus Knufia petricola N2 - Introduction: Rock-inhabiting black fungi are renowned for their constitutive melanin production, extremotolerance and ubiquitous colonization of oligotrophic, natural or anthropogenic subaerial surfaces, including marble monuments and solar panels. Knufia petricola is a model for these fungi as it is genetically amenable and has their typical characteristics. It is capable of colonizing and deteriorating minerals and produces extracellular polymeric substances that facilitate attachment. Objectives: The objective of this study is to understand how such an organism is able to grow in environments depleted of C and/or N. Method: K. petricola growth parameters (colony extension and thickness, biomass, CO2 respiration and carbon-use efficiency (CUE)) were analysed for different C to N ratios (C:N), changing both the C and N concentrations and sources. The study utilized a dual-scale approach, examining biofilm formation on agar (macroscale) and growth of a single cell into a microcolony in a microfluidic device (microscale). This methodology provided insights into the nutritional requirements and growth behaviours of K. petricola across different spatial scales. Findings: Our macroscale analysis indicated optimal growth at the C:N ratio of 60. The morphological analysis demonstrated that when nitrate is utilized as the N source, colonies tend to exhibit filamentous growth at their edges, especially when glucose is available as C source. In contrast, when ammonium is the N source, the colony surface appears smooth (Fig. 1A). Moreover, C or N depletion led to higher substrate penetration, mostly through filaments at the edge of the biofilm. Notably, the lowest carbon concentration yielded reduced biomass C:N ratio and the peak biomass C:N ratio was observed at the medium C:N ratio of 60, suggesting a potential correlation between C:N ratio and optimal growth (Fig. 1B). The CUE was however quite low, ca. 0.4-0.6, being lowest when C and N were limiting. Concurrently, microscale analyses of single cells revealed that increasing the C:N ratio from 0.6 to 60 caused (1) shorter cell cycles and (2) more branching, no branching formed without C and N (Fig. 1C). This led to a denser colony at optimal conditions and a rather extended morphology under C or N limitations. Conclusion: The findings demonstrate that the depletion of either carbon or nitrogen results in enhanced substrate penetration, predominantly through edge filaments. Notably, the optimal growth and peak biomass C:N ratio of 60 suggest both a correlation with and importance of the medium C:N ratio. Specifically, the lowest carbon input led to a reduced biomass C:N ratio, while the peak biomass C:N ratio was achieved at the medium C:N ratio of 60. T2 - FEMS MICRO conference CY - Milano, Italy DA - 14.07.2025 KW - Black fungi KW - Carbon-use efficiency KW - Polyextremotolerant KW - Oligotrophs KW - Rock-inhabiting fungi PY - 2025 AN - OPUS4-65038 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 - Piehl, Patrick T1 - Thermochemical Treatment of Steel Work Dusts and Sludges for the Recovery of Zinc and Iron N2 - Steel work dusts and sludges usually contain severe amounts of zinc, lead, cadmium, and other heavy metals, which hinder direct recycling and make these materials potentially hazardous for the environment. To tackle this issue, here, two thermochemical treatment methods for the reductive workup of blast furnace sludge, electric arc furnace dust, and comparable steelwork dusts are presented. In the first method, carbon contained blast furnace sludge is employed as reducing agent for the material’s metal oxides. By this, heavy metals get evaporated and a metallic iron containing residue that may be reused in electric arc furnace steelmaking is formed. Additionally, the use of hydrogen for reducing iron and heavy metal oxides in steelwork dusts is presented. Here, high evaporation rates of heavy metals can be reached, and sponge iron is formed. Investigations using thermogravimetry and equilibrium simulations provide insides into the reactions taking place. For both processes an upscaling to pilot scale is ongoing. T2 - EUROSLAG 2024 CY - Bilbao, Spain DA - 23.10.2024 KW - Electric arc furnace dust KW - Blast furnace sludge KW - Recycling KW - Ressource recovery KW - Zinc PY - 2024 AN - OPUS4-61499 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Erdmann, Eileen T1 - A random mutagenesis approach to elucidate the biology of extremotolerant black fungi N2 - Microcolonial black fungi ubiquitously inhabit sun-exposed natural and man-made surfaces of our planet. To promote genetic studies, which are hindered by slow growth, lack of sexual cycles and transformation difficulties, CRISPR/Cas9-based genetic tools were implemented (Erdmann et al. 2022, Front Fungal Biol). Now efficient targeted mutagenesis of the rock inhabitant Knufia petricola (Eurotiomycetes/Chaetothyriales) - as a representative of the polyphyletic group of black fungi - enables the elucidation of extremotolerance, oligotrophism, unusual types of cell division, mineral weathering and symbiotic interactions. Still more progress on assigning functions to yet unknown genes can be expected if a forward genetics approach is available. We chose the two-component Activator/ Dissociation (Ac/Ds) transposon system from maize for generating a collection of insertional mutants by in-vivo mutagenesis of K. petricola. For the optimal use of this genetic tool, an inducible promoter for the expression of the Ac transposase (AcTPase) and by this the regulatable transposition of the resistance cassette-containing Ds transposon is desired. However, endogenous promoters for nitrate assimilation and galactose catabolism - often used in fungi for regulatable gene expression - are not inducible by their substrates in K. petricola suggesting that the regulatory networks for nutrient acquisition differ significantly in oligotrophic fungi. Therefore, the metabolism-independent Tet-on system was combined with the AcTPase coding sequence and subsequently transformed into Ds-carrying K. petricola strains. In total, four auxotrophic Ac|Ds starter strains containing the Ds transposon at different position of ade2 or ura3 were generated. The cultivation of these strains with doxycycline for induction of TET::Ac and subsequent selection of cells on ADE/URA-lacking media resulted in prototrophic colonies (revertants) for some but not all Ac|Ds strains. Currently, the transposition events in the obtained revertants are studied to validate the procedure. First amplicon sequencing of excision sites revealed footprint patterns, proving the transposon jumped. T2 - 16th European Conference on Fungal Genetics CY - Innsbruck, Austria DA - 05.03.2023 KW - Rock-inhabiting fungi KW - Foward genetics KW - In-vivo mutagenesis PY - 2023 AN - OPUS4-57144 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -