TY - CONF A1 - Schumacher, Julia T1 - Photoperception in black fungi that share niches with green organisms N2 - Sunlight, the major source of energy, drives life but in excess it provokes UV-induced DNA damage, accumulation of reactive oxygen species, desiccation, osmotic stresses and so on. Biological strategies to survive excess light include protection, avoidance and active utilisation. Phototrophic organisms including cyanobacteria, green algae and plants use all three strategies. Fungi occupying phototrophic niches may profit from the surplus photosynthetic products which also obliges them to cope with the same light-induced stresses. One way of handling these stresses would be to use similar signalling pathways to sense the presence and to interact with their phototrophic partners. Obviously, the levels of adaptation and responses to light will depend on the environment as well as fungal genotype and phylogenetic position. Black fungi – a polyphyletic group – accumulate the dark pigment DHN melanin in their cell walls and often occupy light-flooded habitats from phyllosphere to rock surfaces. Here we compare two sequenced melanised fungi of different lifestyles in their response to light. The Leotiomycete Botrytis cinerea is an aggressive pathogen that primarily infects the above-ground parts of plants. It possesses large numbers of photoreceptors that respond to a broad spectrum of light. As a consequence, light controls morphogenesis in which it induces conidiation for disease spreading and represses sclerotial development for survival and/or sexual recombination. Cellular components involved in photo-perception and regulation of morphogenesis, stress responses and virulence have been identified and appear to regulate propagation, survival and infection. These include phytochromes, a group of photoreceptors which are particularly enriched in the Leotiomycetes and that mediate coordinated responses to light and elevated temperatures. Assuming that photo-regulation may be equally important for fungi that live in mutualistic relationships with phototrophs either by forming composite organisms or biofilms, we investigate the role of light in the rock-inhabiting Eurotiomycete Knufia petricola. Like other black yeasts, K. petricola grows slowly, does not form specialised reproductive structures and constitutively produces DHN melanin as well as carotenoids. Combining K. petricola with the cyanobacterium Nostoc punctiforme, we developed a model system for studying biofilm formation and bio-weathering. A genetic toolbox to manipulate this model system is being developed. K. petricola strain A95 possesses ten putative photoreceptors, more than found in filamentous Eurotiomycetes suggesting that light plays an important role for abiotic and biotic interactions in extremo-tolerant and symbiosis-capable fungi. T2 - International Symposium on Fungal Stress (ISFUS) CY - Sao Jose dos Campos, Brazil DA - 19.05.2019 KW - Botrytis KW - carotenoids KW - Knufia KW - melanin KW - Nostoc PY - 2019 AN - OPUS4-48130 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Torge, Manfred A1 - Seneschal-Merz, Karine A1 - Günther, Tobias A1 - Wilsch, Gerd T1 - Determination of boron in 19th and 20th century paint layers using LIBS N2 - 19th and 20th centuries glass paint layers consist of a colour body and a colourless lead silicate flux, in which borax or boric acid was added as further component to improve the paint ability and to reduce the firing temperature for multiple layers of paint. Model glasses were used in laboratory tests to investigate the stability of glass paints with additions of boron oxide. To determine boron in paint layers, a LIBS-system with pulsed NdYAG-laser was used. T2 - Technart 2019 CY - Brugge, Belgien DA - 07.05.2019 KW - Stained glass windows KW - Glass paints KW - LIBS PY - 2019 AN - OPUS4-48229 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gorbushina, Anna T1 - Microbiology / biofilms in material research and testing N2 - In the modern world there is an increased understanding that design and performance monitoring of materials have to be tested in connection to chemical, physical and (micro)biological challenges. A systematic study on how biofilms interact with materials and what could be done to engineer biofilms and/or materials in order to maximize the resistance of the material (surface) or the resistance the biofilm-modified material (bulk) is in strong need. In the Department “Materials and the Environment” of the BAM new experimental platform is being developed. With the help of different type of device for high throughput and microbiologically-controlled environment simulation we establish a new approach to clarify the mechanisms of biofilm/material interactions. Despite the focus on fundamental research, the main results of this project proposal will be transferable into material technology and construction chemistry and will influence the development of standardization in this topic. As the interactions of biofilms and materials have implications for most constructions as well as climate change, the results of the research generates additional value. T2 - Initialgespräch - DFG-Forschungsgruppe "Mikrobiologie/Biofilme" CY - Karlsruhe, Germany DA - 14.11.2019 KW - Biofilm KW - Microbiology KW - Black fungi KW - Solar panel PY - 2019 AN - OPUS4-50199 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gorbushina, Anna T1 - Life on the rocks - Black fungi from biofilms on material-atmosphere interface N2 - Interface between the atmosphere and mineral substrates is the oldest terrestrial habitat. Morphologically simple microbial biofilms were the first settlers on these inhospitable surfaces at times when the Earth was inhabited only by microorganisms and the solid substrates represented only by natural rock surfaces i.e. lithosphere. Miniature, self-sufficient microbial ecosystems continue to develop on subaerial (i.e. air-exposed) solid surfaces at all altitudes and latitudes where direct contact with the atmosphere and solar radiation occurs – on rocks, mountains, buildings, monuments, solar panels. All these sub-aerial biofilms develop under fluctuating and hostile conditions – and thus frequently harbour stress-tolerant black fungi inherently able to cope with the stresses of bright sunlight and constantly changing atmospheric conditions. Black fungi – a polyphyletic group of Ascomycetes– accumulate the dark pigment DHN melanin, diverse carotenoids and mycosporines in their cells and thus successfully colonise sunlight-flooded habitats from phyllosphere to rock surfaces. Various chemical and physical extremes and fluctuating environments belong to the challenges effectively mastered by black fungi. In our laboratory we isolate novel black fungi from man-made habitats like building materials and solar panels. Using Knufia petricola A95 as a model we conduct experiments to clarify interactions of black fungi with inorganic substrates. We use available mutants to determine the functional consequences of changes in the outer cell wall envelopes – from excreted EPS to layers of protective pigments. A genetic toolbox to manipulate this Chaetothyriales representative is in further development. Our long-term goal is to understand the fundamental mechanisms how black fungi are able (i) to adhere to dry atmosphere-exposed surfaces, (ii) to survive multiple stresses and (iii) to change the underlying substrates including rocks. T2 - International Symposium on Fungal Stress (ISFUS) CY - São José dos Campos, Brazil DA - 19.05.2019 KW - Subaerial biofilm KW - Melanins KW - Carotenoids KW - Knufia KW - Mineral weathering PY - 2019 AN - OPUS4-50200 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gorbushina, Anna T1 - Life on the rocks and other hard surfaces N2 - The story of how black fungi survive harsh conditions on sun-exposed desert rocks and material surfaces is fascinating. In the presentation examples of how knowledge of these organisms can be of practical value (e.g., in biodeterioration studies, such as on stone markers in cemeteries) would be given. Among other stories, the example of how roof tiles amended with a titanium oxide layers as a biocide actually selected for the black fungi will be told. A hypothesis about how these organisms would likely be found on solar panels and some early BAM work in that area will be presented. This then brings the connection to a study ripe for investigation in North Carolina. The talk presents the development of a study aiming at deciphering the influence of microbial biofilm formation on the energy conversion efficiency of solar photovoltaic panels or modules at two facilities (one facility under the impact of high intensity of animal agriculture and high deposition of ammonia from atmosphere and the other with low animal agriculture and lower atmospheric ammonia deposition) in North Carolina. The main hypothesis of the study is that microbial biofilm formation on solar photovoltaic panels will lead to significant decreases in energy conversion efficiency of solar photovoltaic modules and biofilm formation will also be accelerated by high ammonia concentration in the ambient atmosphere and high nitrogen deposition. T2 - Dr. Michael D. Aitken Symposium CY - Chapel Hill, NC, USA DA - 08.11.2019 KW - Black fungi KW - Solar panel KW - Biofilm PY - 2019 AN - OPUS4-50125 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Gerrits, Ruben T1 - Data of "An experimental study of fungal olivine weathering" N2 - This file contains all the data used for the figures shown in the Dissertation of Ruben Gerrits with the title "An experimental study of fungal olivine weathering". In this study, the weathering-affecting, rock-inhabiting fungus, Knufia petricola A95 and the Fe-bearing olivine (Fe0.2Mg1.8SiO4) were selected to investigate fungi-induced effects on mineral dissolution. The availability of a melanin-deficient mutant (ΔKppks) of K. petricola A95, that produced more extracellular polymeric substances (EPS) than the wild type (WT), enabled comparative studies of the role of melanin and EPS in weathering processes. KW - Olivine KW - Weathering KW - Fungus PY - 2019 DO - https://doi.org/10.26272/opus4-48770 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-48770 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Trimpert, J. A1 - Groenke, N. A1 - Kunec, D. A1 - Eschke, K. A1 - He, Shulin A1 - McMahon, Dino Peter A1 - Osterrieder, N. T1 - A proofreading-impaired herpesvirus generates populations with quasispecies-like structure JF - Nature Microbiology N2 - RNA virus populations are composed of highly diverse individuals that form a cloud of related sequences commonly referred to as a ‘quasispecies’1–3. This diversity arises as a consequence of low-fidelity genome replication4,5. By contrast, DNA Virus populations contain more uniform individuals with similar fitness6. Genome diversity is often correlated with increased Fitness in RNA viruses, while DNA viruses are thought to require more faithful genome replication. During DNA replication, erroneously incorporated bases are removed by a 3′-5′ exonuclease, a highly conserved enzymatic function of replicative DNA but not RNA polymerases. This proofreading process enhances replication fidelity and ensures the genome integrity of DNA organisms, including large DNA viruses7. Here, we show that a herpesvirus can tolerate impaired exonucleolytic proofreading, resulting in DNA virus populations, which, as in RNA viruses8, are composed of highly diverse genotypes of variable individual fitness. This indicates that herpesvirus mutant diversity may compensate for individual Fitness loss. Notably, in vivo infection with diverse virus populations results in a marked increase in virulence compared to genetically homogenous parental virus. While we cannot exclude that the increase in virulence is caused by selection of and/or interactions between individual genotypes, our findings are consistent with quasispecies dynamics. Our results contrast with traditional views of DNA virus replication and evolution, and indicate that a substantial increase in population diversity can lead to higher virulence. KW - Marek's virus KW - Virulence KW - Quasispecies KW - Evolution PY - 2019 DO - https://doi.org/10.1038/s41564-019-0547-x SN - 2058-5276 N1 - Corrigendum: Nature Microbiology 4 (2019) 2025 VL - 4 SP - 2175 EP - 2183 PB - Nature Publishing Group CY - London AN - OPUS4-48896 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pokharel, R. A1 - Gerrits, Ruben A1 - Schuessler, J. A1 - von Blanckenburg, F. T1 - Mechanisms of olivine dissolution by rock-inhabiting fungi explored using magnesium stable isotopes JF - Chemical Geology N2 - To unravel the dissolution mechanisms of olivine by a rock-inhabiting fungus we determined the stable isotope ratios of Mg on solutions released in a laboratory experiment. We found that in the presence of the fungus Knufia petricola the olivine dissolution rates were about seven-fold higher (1.04×10−15 mol cm−2 s−1) than those in the abiotic experiments (1.43×10−16 mol cm−2 s−1) conducted under the same experimental condition (pH 6, 25 °C, 94 days). Measured element concentrations and Mg isotope ratios in the supernatant solutions in both the biotic and the abiotic experiment followed a dissolution trend in the initial phase of the experiment, characterized by non-stoichiometric release of Mg and Si and preferential release of 24Mg over 26Mg. In a later phase, the data indicates stoichiometric release of Mg and Si, as well as isotopically congruent Mg release. We Attribute the initial non-stoichiometric phase to the rapid replacement of Mg2+ in the olivine with H+ along with simultaneous polymerization of Si tetrahedra, resulting in high dissolution rates, and the stoichiometric phase to be influenced by the accumulation of a Si-rich amorphous layer that slowed olivine dissolution. We attribute the accelerated dissolution of olivine during the biotic experiment to physical attachment of K. petricola to the Si-richamorphous layer of olivine which potentially results in ist direct exposure to protons released by the fungal cells. These additional protons can diffuse through the Si-rich amorphous layer into the crystalline olivine. Our results also indicate the ability of K. petricola to dissolve Fe precipitates in the Si-rich amorphous layer either by protonation, or by Fe(III) chelation with siderophores. Such dissolution of Fe precipitates increases the porosity of the Si-rich amorphous layer and hence enhances olivine dissolution. The acceleration of mineral dissolution in the presence of a rock-dissolving fungus further suggests that its presence in surficial CO2 sequestration plants may aid to accelerate CO2 binding. KW - Olivine KW - Magnesium KW - Isotopes KW - Fungus PY - 2019 DO - https://doi.org/10.1016/j.chemgeo.2019.07.001 SN - 0009-2541 SN - 1872-6836 VL - 525 SP - 18 EP - 27 PB - Elsevier AN - OPUS4-48824 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Gerrits, Ruben T1 - An experimental study of fungal olivine weathering N2 - Free-living and (ecto)-mycorrhizal fungi enhance rock weathering. In their roles as mineral weathering agents and mutualistic partners of phototrophs, fungi supply primary producers like plants and phototrophic microorganisms with mineral-derived nutrients. The exact mechanisms behind fungus-induced mineral weathering processes are however not well understood. Progress can be achieved here by reproducible experimental simulations of the natural processes, using well-characterised model organisms and minerals. In this study, the weathering-affecting, rock-inhabiting fungus, Knufia petricola A95 and the Fe-bearing olivine (Fe0.2Mg1.8SiO4) were selected to investigate fungi-induced effects on mineral dissolution. The availability of a melanin-deficient mutant (ΔKppks) of K. petricola A95, that produced more extracellular polymeric substances (EPS) than the wild type (WT), enabled comparative studies of the role of melanin and EPS in weathering processes. Three experimental systems, which generate long-term microbiological stability, were developed to study the impact of the WT and ΔKppks on olivine weathering: (1) batch and (2) mixed flow dissolution experiments, and (3) biofilm cultivation experiments. In addition, state-of-the-art analytical techniques were used to monitor changes in the growth medium, as well as of the mineral surface and biofilm-mineral interface. Inductively coupled plasma optical emission spectrometry (ICP-OES) analysis of the Mg, Si and Fe concentrations in the reacted growth medium was used to quantify olivine dissolution. In abiotic controls, Mg and Si dissolved congruently, while Fe precipitated. The measured olivine dissolution rates at pH 6 were two orders of magnitude lower than previously reported, but similar at acidic pH. X-ray photoelectron spectroscopy (XPS) analyses of the olivine surface confirmed the presence of Fe (oxyhydr)oxide precipitates. Transmission electron microscopy (TEM) imaging of an abiotically reacted polished olivine section from the long-term cultivation experiment showed the presence of an amorphous layer enriched in Fe. All these observations indicate that the precipitation of Fe (oxyhydr)oxides on the olivine surface inhibits olivine dissolution. Both tested rock-inhabiting fungal strains affect Fe precipitation as well as olivine dissolution. Evaluation of the WT and ΔKppks revealed that the WT formed less biomass but could take up higher amounts of metals (e.g. Fe) and was more efficient in its attachment to olivine. The WT and ΔKppks enhanced olivine dissolution as demonstrated by higher Mg and Si concentration in the reacted growth medium. They furthermore prevented Fe precipitation by binding Fe and retaining it in solution, thereby allowing olivine dissolution to proceed. The WT cells that were attached to the olivine surface were particularly efficient at inhibiting Fe precipitation. By binding Fe directly at the olivine surface, the WT cells removed the inhibition of olivine dissolution almost completely. TEM analysis of polished olivine sections, colonised by a fungal biofilm for seven months, supported this hypothesis. After long-term fungus-olivine interaction, the Fe-enriched, amorphous layer did not develop, and the olivine surface was stronger etched compared to the abiotic control. To study the effect of mutualism on mineral weathering, K. petricola was grown with the cyanobacterium, Nostoc punctiforme ATCC 29133. Both partners showed an enhanced growth and formed a stratified biofilm which attached more strongly to olivine. Nevertheless, the olivine dissolution rate of the fungus-cyanobacterium consortium was moderate. Rock weathering simulation systems developed here are promising research instruments. The experimental conditions allow for the alteration of the studied mineral surface, while the clear definition of these conditions delivers a stable growth of microorganisms. The latter makes these systems universally applicable, especially in combination with integrative multidisciplinary analytics. Processes underlying environmental and biological effects on rock weathering, metal corrosion, plastic degradation, or the deterioration of any other substrate can be studied reproducibly and over a long period of time. The chemical and biological complexity of these simulation systems mimics natural rock weathering processes. The mineral dissolution rates generated in this study are therefore relevant to natural ecosystems. KW - Olivine KW - Weathering KW - Fungus PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:188-refubium-25125-1 DO - https://doi.org/10.17169/refubium-2880 SP - 1 EP - 178 PB - Freie Universität Berlin CY - Berlin AN - OPUS4-48825 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Brusamarello-Santos, L. C. C. A1 - Alberton, D. A1 - Valdameri, G. A1 - Camilios-Neto, D. A1 - Covre, R. A1 - Lopes, K. d. P. A1 - Zibetti Tadra-Sfeir, M. A1 - Faoro, H. A1 - Adele Monteiro, R. A1 - Barbosa-Silva, A. A1 - Broughton, William John A1 - Oliveira Pedrosa, F. A1 - Wassem, R. A1 - de Souza, E.M. T1 - Modulation of defence and iron homeostasis genes in rice roots by the diazotrophic endophyte Herbaspirillum seropedicae JF - Scientific Reports N2 - Rice is staple food of nearly half the world’s population. Rice yields must therefore increase to feed ever larger populations. By colonising rice and other plants, Herbaspirillum spp. stimulate plant growthand productivity. However the molecular factors involved are largely unknown. To further explore this interaction, the transcription profiles of Nipponbare rice roots inoculated with Herbaspirillum seropedicae were determined by RNA-seq. Mapping the 104 million reads against the Oryza sativa cv. Nipponbare genome produced 65 million unique mapped reads that represented 13,840 transcripts each with at least two-times coverage. About 7.4% (1,014) genes were differentially regulated and of these 255 changed expression levels more than two times. Several of the repressed genes encoded proteins related to plant defence (e.g. a putative probenazole inducible protein), plant disease resistance as well as enzymes involved in flavonoid and isoprenoid synthesis. Genes related to the synthesis and efflux of phytosiderophores (PS) and transport of PS-iron complexes were induced by the bacteria. These data suggest that the bacterium represses the rice defence system while concomitantly activating iron uptake. Transcripts of H. seropedicae were also detected amongst which transcripts of genes involved in nitrogen fixation, cell motility and cell wall synthesis were the most expressed. KW - Herbaspirillum seropedicae KW - Pathogen KW - Rice KW - qPCR KW - Genome PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-490122 DO - https://doi.org/10.1038/s41598-019-45866-w SN - 2045-2322 VL - 9 SP - 10573-1 EP - 10573-15 PB - Nature CY - London AN - OPUS4-49012 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -