TY - GEN A1 - Breitenbach, Romy A1 - Gerrits, Ruben A1 - Dementyeva, Polina A1 - Knabe, Nicole A1 - Schumacher, Julia A1 - Feldmann, Ines A1 - Radnik, Jörg A1 - Ryo, M. A1 - Gorbushina, Anna T1 - Data for "The role of extracellular polymeric substances of fungal biofilms in mineral attachment and weathering" N2 - Data for the publication "The role of extracellular polymeric substances of fungal biofilms in mineral attachment and weathering" (https://doi.org/10.1038/s41529-022-00253-1). It includes: - The Summary of the EPS concentration, EPS sugar components and EPS linkages. - The Summary of the XPS analysis of freeze-dried biofilm samples of all strains. - The Summary of the pH, Mg, SI and Fe concentration, biomass and olivine dissolution rate for each time point of all dissolution experiments. KW - Biofilms PY - 2022 U6 - https://doi.org/10.26272/opus4-54901 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-54901 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Breitenbach, Romy A1 - Gerrits, Ruben A1 - Dementyeva, Polina A1 - Knabe, Nicole A1 - Schumacher, Julia A1 - Feldmann, Ines A1 - Radnik, Jörg A1 - Ryo, M. A1 - Gorbushina, Anna T1 - The role of extracellular polymeric substances of fungal biofilms in mineral attachment and weathering N2 - The roles extracellular polymeric substances (EPS) play in mineral attachment and weathering were studied using genetically modified biofilms of the rock-inhabiting fungus Knufia petricola strain A95. Mutants deficient in melanin and/or carotenoid synthesis were grown as air-exposed biofilms. Extracted EPS were quantified and characterised using a combination of analytical techniques. The absence of melanin affected the quantity and composition of the produced EPS: mutants no longer able to form melanin synthesised more EPS containing fewer pullulan-related glycosidic linkages. Moreover, the melanin-producing strains attached more strongly to the mineral olivine and dissolved it at a higher rate. We hypothesise that the pullulan-related linkages, with their known adhesion functionality, enable fungal attachment and weathering. The released phenolic intermediates of melanin synthesis in the Δsdh1 mutant might play a role similar to Fe-chelating siderophores, driving olivine dissolution even further. These data demonstrate the need for careful compositional and quantitative analyses of biofilm-created microenvironments. KW - Biofilms PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-549025 SN - 2397-2106 VL - 6 SP - 1 EP - 11 PB - Springer Nature CY - London AN - OPUS4-54902 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gerrits, Ruben A1 - Pokharel, R. A1 - Breitenbach, Romy A1 - Radnik, Jörg A1 - Feldmann, Ines A1 - Schuessler, J.A. A1 - von Blanckenburg, F. A1 - Gorbushina, Anna A1 - Schott, J. T1 - How the rock-inhabiting fungus K. petricola A95 enhances olivine dissolution through attachment N2 - Free-living and mycorrhizal fungi are able to enhance the weathering of rock and other solid substrates. Deciphering the exact mechanisms of these natural processes requires their experimental simulation. Moreover, by performing these simulations with genetically amenable rock-weathering fungi, one can knock-out certain fungal traits and consequently identify their weathering-relevant function. Here, the effect of the rock-inhabiting fungus, Knufia petricola A95, on the dissolution kinetics of an Fe-bearing olivine (Mg1.86Fe0.19SiO4) is investigated at 25 °C and pH 6 using reproducible batch and mixed flow experiments. The availability of a melanin-deficient mutant (ΔKppks) of K. petricola A95, which produces more extracellular polymeric substances (EPS) than the wild type (WT), enables the comparative study of the role of melanin and EPS in olivine dissolution. In abiotic dissolution experiments, the olivine dissolution rate decreased considerably over time at pH 6 but not at pH 3.5. This inhibition of abiotic olivine dissolution at pH 6 was most likely caused by the in-situ oxidation of ferrous Fe and/or the precipitation of ferric hydroxides at the olivine surface. In corresponding biotic experiments at pH 6, both the wild type K. petricola and its melanin-deficient mutant ΔKppks solubilised and bound significant amounts of Fe released by olivine dissolution. Fe oxidation and precipitation were thus prevented and olivine dissolution proceeded faster than in the abiotic experiments. By sequestering Fe directly at the olivine surface, the attached wild type K. petricola cells were particularly efficient at preventing the oxidation of Fe at the mineral surface: the slowdown of olivine dissolution almost completely disappeared. The attachment capacity of these wild type cells is most likely mediated by wild type-specific EPS. Our presented experimental systems allow the oxidation of mineral-released Fe and include a rock-inhabiting fungus, thus simulating chemical, physical and biological conditions that set dissolution rates in a way that is relevant to natural ecosystems. KW - Black fungi KW - Bio-weathering KW - Forsterite KW - Knock-out mutant KW - Extracellular polymeric substances KW - Melanin Adhesion PY - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-509332 VL - 282 SP - 76 EP - 97 PB - Elsevier Ltd. AN - OPUS4-50933 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Lessovaia, S.N. A1 - Gerrits, Ruben A1 - Gorbushina, Anna A1 - Polekhovsky, Y.S. A1 - Dultz, S. A1 - Kopitsa, G.G. ED - Frank-Kamenetskaya, O.V. ED - Vlasov, D. ED - Panova, E.G. ED - Lessovaia, S.N. T1 - Modeling Biogenic Weathering of Rocks from Soils of Cold Environments N2 - Morphologically simple and microbially dominated ecosystems termed “biofilms” have existed on Earth for a long period of biosphere evolution. A model biofilm combining one heterotroph and one phototroph component was used in a laboratory experiment to simulate biogenic weathering with two different specimens of basic rock samples from the soil profiles. The rocks fragments from the regions of cold environments of Eurasia,where abiotic physical processes, including rock disintegration initiated by freezing–thawing cycles, represent the most probable Scenario of rock weathering, were subjected to biological colonization. The rock Fragments were represented by dolerite and metagabbro amphibolites. Polished sections of the rock samples were inoculated with the model microbiological consortium of the oligotrophic fungus and the phototrophic cyanobacteria (biofilm). After 3 month runtime of the experiment the progress of rock weathering was derived from the growth of the biofilm on the rock surfaces. The model biofilm visualization on the rock surface of polished sections illustrated their stronger development namely on dolerite in comparison with metagabbro amphibolite. The findings confirmed the higher sensitivity of dolerite to biogenic weathering due to (i) mineral association, in which quartz was absent and (ii) porosity providing higher specific surface area for biotic—abiotic interaction influenced by the occurrence of micro-porosity in the rock. KW - Biogenic weathering KW - Rock leaching KW - Fractal structure KW - Biofilm formation KW - Internal pores PY - 2020 U6 - https://doi.org/10.1007/978-3-030-21614-6_27 SP - 501 EP - 515 PB - Springer AN - OPUS4-51442 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gerrits, Ruben A1 - Wirth, R. A1 - Schreiber, A. A1 - Feldmann, Ines A1 - Knabe, Nicole A1 - Schott, J, A1 - Benning, L.G. A1 - Gorbushina, Anna T1 - High-resolution imaging of fungal biofilm-induced olivine weathering N2 - Many microorganisms including free-living and symbiotic fungi weather minerals through the formation of biofilms on their surface. Weathering thus proceeds not only according to the mineral’s chemistry and the environmental conditions but also according to the local biofilm chemistry. These processes can be dissected in experiments with defined environmental settings and by employing genetic tools to modify traits of the fungal biofilm. Biofilms of the rock-inhabiting fungus Knufia petricola strain A95 (wild-type, WT) and its melanin-deficient mutant (ΔKppks) were grown on polished olivine sections in subaerial (air-exposed) and subaquatic (submerged) conditions. After seven months of interaction at pH 6 and 25°C, the fungus-mineral interface and abiotic olivine surface were compared using high resolution transmission electron microscopy (HRTEM). The abiotic, subaquatic olivine section showed a 25 nm thick, continuous amorphous layer, enriched in Fe and depleted in Si compared to the underlying crystalline olivine. This amorphous layer formed either through a coupled interfacial dissolution reprecipitation mechanism or through the adsorption of silicic acid on precipitated ferric hydroxides. Its thickness was likely enhanced by mechanical stresses of polishing. Directly underneath a fungal biofilm (WT and mutant alike), the surface remained mostly crystalline and was strongly etched and weathered, indicating enhanced olivine dissolution. The correlation between enhanced olivine dissolution and the absence of a continuous amorphous layer is a strong indication of the dissolution-inhibiting qualities of the latter. We propose that the fungal biofilm sequesters significant amounts of Fe, preventing formation of the amorphous layer and driving olivine dissolution onwards. The seemingly similar olivine surface underneath both WT and mutant biofilms illustrates the comparably insignificant role of specific biofilm traits in the weathering of olivine once biofilm attachment is imposed. Under subaerial conditions, the absence of water on the abiotic surface prohibited olivine dissolution. This was overcome by the water retention capacities of both the WT and mutant biofilm: the olivine surface underneath subaerial fungal biofilms was as weathered as the corresponding subaquatic olivine surface. Under the studied environmental settings, the effect of fungal biofilms on olivine weathering seems to be universal, independent of the production of melanin, the composition of extracellular polymeric substances (EPS) or air-exposure. KW - Bio-weathering KW - Forsterite KW - Extracellular polymeric substances KW - Melanin KW - Black fungi PY - 2021 U6 - https://doi.org/10.1016/j.chemgeo.2020.119902 VL - 559 SP - 119902 PB - Elsevier B.V. AN - OPUS4-51403 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rasesh, Pokharel A1 - Gerrits, Ruben A1 - Schuessler, Jan A. A1 - Floor, Geerke H. A1 - Gorbushina, Anna A1 - von Blanckenburg, Friedhelm T1 - Mg isotope fractionation during uptake by a rock-inhabiting, model microcolonial fungus Knufia petricola at acidic and neutral pH N2 - The model rock-inhabiting microcolonial fungus Knufia petricola fractionates stable Mg isotopes in a time and pH-dependent manner. During growth, the increase of 26Mg/24Mg in the fungal cells relative to the growth media amounted to 0.65 ± 0.14‰at pH 6 and 1.11 ± 0.35‰at pH 3. We suggest a constant equilibrium fractionation factor during incorporation of Mg into ribosomes and ATP as a cause of enrichment of 26Mg in the cells. We suggest too that the proton gradient across the cell wall and cytoplasmic Membrane controls Mg2+ transport into the fungal cell. As the strength of this gradient is a function of extracellular solution pH, the pHdependence on Mg isotope fractionation is thus due to differences in fungal cell mass fluxes. Through a mass balance model we show that Mg uptake into the fungal cell is not associated with a unique Mg isotope fractionation factor. This Mg isotope fractionation dependence on pH might also be observed in any organism with cells that follow similar Mg uptake and metabolic pathways and serves to reveal Mg cycling in ecosystems. KW - Isotope fractionation KW - Fungus KW - Magnesium PY - 2017 U6 - https://doi.org/10.1021/acs.est.7b01798 SN - 0013-936X SN - 1520-5851 VL - 51 IS - 17 SP - 9691 EP - 9699 PB - ACS Publications CY - USA AN - OPUS4-43018 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pokharel, R. A1 - Gerrits, Ruben A1 - Schuessler, J. A. A1 - Frings, P. J. A1 - Sobotka, R. A1 - Gorbushina, Anna A1 - von Blanckenburg, F. T1 - Magnesium stable isotope fractionation on a cellular level explored by cyanobacteria and black fungi with implications for higher plants N2 - In a controlled growth experiment we found that the cyanobacterium Nostoc punctiforme has a bulk cell 26Mg/24Mg ratio (expressed as δ26Mg) that is −0.27‰ lower than the growth solution at a pH of ca. 5.9. This contrasts with a recently published δ26Mg value that was 0.65‰ higher than growth solution for the black fungus Knufia petricola at similar laboratory conditions, interpreted to reflect loss of 24Mg during cell growth. By a mass balance model constrained by δ26Mg in chlorophyll extract we inferred the δ26 Mg value of the main Mg compartments in a cyanobacteria cell: free cytosolic Mg (−2.64‰), chlorophyll (1.85‰), and the nonchlorophyll-bonded Mg compartments like ATP and ribosomes (−0.64‰). The lower δ26Mg found in Nostoc punctiforme would thus result from the absence of significant Mg efflux during cell growth in combination with either (a) discrimination against 26Mg during uptake by desolvation of Mg or transport across protein channels or (b) discrimination against 24Mg in the membrane transporter during efflux. The model predicts the preferential incorporation of 26Mg in cells and plant organs low in Mg and the absence of isotope fractionation in those high in Mg, corroborated by a compilation of Mg isotope ratios from fungi, bacteria, and higher plants. KW - Cyanobacteria KW - Black fungi KW - Nostoc punctiforme KW - Knufia petricola KW - Magnesium PY - 2018 U6 - https://doi.org/10.1021/acs.est.8b02238 SN - 1520-5851 SN - 0013-936X VL - 52 IS - 21 SP - 12216 EP - 12224 PB - ACS Publications AN - OPUS4-46832 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -