TY - CONF A1 - Brandt, S. T1 - Odour Emissions from Building Products Simplifying the Evaluation of Perceived Intensity N2 - One criterion to evaluate the odour of a sample is perceived intensity П which is evaluated with the aid of a comparative scale. The procedure is well accepted but also time consuming and extensive. The study should help simplify the testing procedure by asking the panel members to only indicate whether a sample is perceived as less to equally intense or of greater intensity in comparison to a given acetone concentration of 7 pi on the comparative scale. In Germany a value of 7 pi is required for products to be suitable for the indoor use. The results show that the simplified test is basically suitable. T2 - Indoor Air Conference 2022 “Healthy people in healthy indoor environment” CY - Kuopio, Finland DA - 12.06.2022 KW - Perceived Intensity KW - Emissions KW - Chamber test KW - Odour KW - VOC KW - Building product PY - 2022 AN - OPUS4-55623 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Braymer, Joseph T1 - Methanobacterium IM1 as a model organism to study MIC N2 - Microbiologically influenced corrosion (MIC), also known as biocorrosion, is a process where microbes corrode metal surfaces causing detrimental damage to manmade infrastructure. Several studies, mainly under anaerobic conditions, have identified sulfate-reducing bacteria and methanogens as key players in biocorrosion. However, an important issue is that most MIC-related microbes at the moment are non-culturable. In addition, improved technologies (i.e., omics, biochemical, and microscopy methods) are needed to study, detect, simulate, and modulate MIC-related cases. Therefore, the selection of strains that can cause MIC, are culturable, and are genetically accessible, are of high importance for establishing new methods to study MIC on the molecular level. For example, the archaeal strain Methanobacterium IM1 has caught great attention due to its involvement in biocorrosion processes. Genes encoding for a novel enzyme (MIC NiFe-hydrogenase) have been proposed in this methanogen to be directly related to the e T2 - International Biodeterioration and Biodegradation Symposium 19 CY - Berlin, Germany DA - 11.09.2024 KW - Biocorrosion KW - Methanogen KW - Iron KW - Hydrogenase KW - Mechanism PY - 2024 AN - OPUS4-61508 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - 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 - Cook, Jake Thomas T1 - Assessment of concrete bioreceptivity in algal biofilm green façade systems N2 - Algal biofilm façades are an alternative to traditional green façades which can help to improve biodiversity and air quality within cities. They present a low maintenance approach in which subaerial algae are grown directly on concrete substrates. The intrinsic bioreceptivity of the substrate is a critical factor in successful facade colonisation. Existing research has identified several environmental and material properties which influence concrete bioreceptivity, however a consensus has yet to be made on which properties are most influential and how the interaction between properties may promote algal biofilm growth under specific conditions. T2 - International Conference on Bio-Based Building Materials CY - Vienna, Austria DA - 21.06.2023 KW - Concrete KW - Façade KW - Bio-receptive KW - Extracellular polymeric substances KW - Fractional factorial PY - 2023 UR - https://www.rilem.net/agenda/5th-international-conference-on-bio-based-building-materials-1501 AN - OPUS4-58976 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 - 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 - Dehkohneh, Abolfazl T1 - Fungal biofilms on materials: describing and modelling growth of the black fungus Knufia petricola N2 - Fungi that grow as biofilms are associated with clinical settings as well as various cases of material fouling and material damage. Black fungi as biofilm formers have been rarely studied so far. Their conspicuous dark pigmentation, EPS production, adhesion capabilities and adaptations to stresses allow black fungi to develop biofilms on materials under harsh conditions. For example, rock-inhabiting black fungi withstand sun irradiation and dehydration and are therefore ubiquitous on arid surfaces like solar panels and marble monuments. To understand and control their ability to colonise and deteriorate materials, one should assess and model black fungi’s growth patterns. But so far, no mathematical model has been developed to describe their growth. Knufia petricola A95, representing rock-inhabiting fungi from Chaetothyriales, is genetically amenable and can serve as a model for biofilm studies in black fungi. The primary objective of this project is to develop a growth model for K. petricola A95 which will enable to define and predict material colonisation of black fungi. Dedicated experimental work with K. petricola will allow the quantitative assessment of the impact of environmental conditions (e.g. pH, nutrients, etc.) on the growth behaviour at the biofilm and single cells level. Data which will be used to validate and develop an individual-based model (based on the iDynoMICS modelling platform) that explains how fungal biofilms form, colonise materials, and cause deterioration. Thus far, research has been conducted on the impact of different concentrations and sources of major elements (e.g. C, N, …), as well as trace elements (e.g. Cu, Mg, …), on the colony shape and biomass of Knufia petricola A95 biofilms. To study the behaviour of single cells, the length of the cell cycle in different growth media has been determined via the combined use of microfluidic devices and confocal microscopy. T2 - IUBMB Focused Meeting on Extremophilic Fungi (FUN-EX) CY - Ljubljana, Slovenia DA - 19.09.2023 KW - Biofilm KW - Rock-inhabiting fungus KW - Mathematical modelling PY - 2023 AN - OPUS4-58438 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dehkohneh, Abolfazl T1 - From microscale to macroscale: how environmental conditions impact the growth of the black fungus Knufia petricola N2 - Environmental, black fungi are known for their oligotrophic lifestyle and melanin production and ubiquitous colonisers of natural and anthropogenic subaerial surfaces like marble monuments, washing machine soap dispensers and solar panels. Even though their growth is generally unappreciated, prevention or inhibition thereof is still to be accomplished. We have chosen the black fungus Knufia petricola as a model species to study these organisms as it is genetically amenable, able to colonise and deteriorate minerals and produces extracellular polymeric substances allowing attachment. Our goal is simple: the quantitative description of its growth on various environmental conditions to create a mathematical model which could allow the development of a mitigation strategy. The conditions to be tested are the quantity and type of carbon and nitrogen sources, the pH and the presence of neighbouring colonies. The mathematical model is in development using the iDynoMiCS 2.0 platform. Our first results showed that the growth rate is negatively correlated to the colony forming units (i.e. the presence of a neighbouring colony). Although interesting with respect to mitigation, we therefore have chosen to track the growth of single colonies. On a macro-scale, the highest extension rates of colonies were at pH 5, 0.01M NO3, 0.01M NH4, 0.1M glucose, and 0.1M sucrose. Interesting are the similar rates in the range of 0.01M to 0.1M for carbon, and that CO2 production on similar conditions correlates well with these results. On a microscale, we have followed the growth of single cells using a custom-made microfluidic flow cell. Overall, first results show that medium containing more carbon not necessarily affected the growth rate but rather the quantity of branches produced by a single cell. This rapidly results in a more compact microcolony versus the more extended colonies on C-deficient media. This more profound knowledge on the growth of black fungi will allow to dissect their role in material deterioration and colonisation. T2 - International Biodeterioration & Biodegradation Society (IBBS) CY - Berlin, Germany DA - 09.09.2024 KW - Black fungi KW - Rock-inhabiting fungi KW - Fungal biofilm KW - Individual-based modelling PY - 2024 AN - OPUS4-62141 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dehkohneh, Abolfazl T1 - From microscale to macroscale: environmental conditions and growth patterns of the black fungus Knufia petricola N2 - Environmental, black fungi are known for their oligotrophic lifestyle and melanin production and ubiquitous colonisers of natural and anthropogenic subaerial surfaces like marble monuments, washing machine soap dispensers and solar panels. Even though their growth is generally unappreciated, prevention or inhibition thereof is still to be accomplished. We have chosen the black fungus Knufia petricola as a model species to study these organisms as it is genetically amenable, able to colonise and deteriorate minerals and produces extracellular polymeric substances allowing attachment. Our goal is simple: the quantitative description of its growth on various environmental conditions to create a mathematical model which could allow the development of a mitigation strategy. The conditions to be tested are the quantity and type of carbon and nitrogen sources, the pH and the presence of neighbouring colonies. The mathematical model is in development using the iDynoMiCS 2.0 platform. Our first results showed that the growth rate is negatively correlated to the colony forming units (i.e. the presence of a neighbouring colony). Although interesting with respect to mitigation, we therefore have chosen to track the growth of single colonies. On a macro-scale, the highest extension rates of colonies were at pH 5, 0.01M NO3, 0.01M NH4, 0.1M glucose, and 0.1M sucrose. Interesting are the similar rates in the range of 0.01M to 0.1M for carbon, and that CO2 production on similar conditions correlates well with these results. On a microscale, we have followed the growth of single cells using a custom-made microfluidic flow cell. Overall, first results show that medium containing more carbon not necessarily affected the growth rate but rather the quantity of branches produced by a single cell. This rapidly results in a more compact microcolony versus the more extended colonies on C-deficient media. This more profound knowledge on the growth of black fungi will allow to dissect their role in material deterioration and colonisation. T2 - CurvoBio 2024 CY - Warsaw, Poland DA - 28.08.2024 KW - Black fungi KW - Rock-inhabiting fungi KW - Fungal biofilm KW - Individual-based modelling KW - Biocorrosion PY - 2024 AN - OPUS4-62270 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 -