TY - CONF A1 - Knabe, Nicole T1 - Targeted disruption of melanin synthesis in rock-inhabiting fungi - a new tool in material science N2 - Melanised rock-inhabiting fungi are found in extreme habitats and along broad spectrum of economically important man-made materials. Black fungi and accompanying organisms can weather rocks and cause significant losses in light availability to solar parks. Understanding these underlying mechanisms requires a set of modern biological techniques and approaches that are under development in our laboratory. T2 - Bio-Geo-Colloquium FSU Jena CY - Jena, Germany DA - 15.11.2016 KW - Melanin KW - Rock-inhabiting fungi KW - Mineral weathering PY - 2016 AN - OPUS4-38566 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Knabe, Nicole T1 - Roles of protective pigments in oxidative stress responses of the rock-inhabiting model fungus Knufia petricola A95 T2 - 28th Fungal Genetics Conference CY - Pacific Grove, California, USA DA - 2015-03-17 PY - 2015 AN - OPUS4-33058 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Knabe, Nicole T1 - Life on the rocks: a simple genetically tractable model system to study fungus-material interactions T2 - Seminar CY - Berlin Center for Genomics in Biodiversity Research (BeGenDiv) DA - 2015-04-15 PY - 2015 AN - OPUS4-33059 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Knabe, Nicole T1 - Oxidative stress response of refractive ascomycetes: genetic manipulation of the rock-inhabiting model fungus Knufia petricola A95 T2 - Microbiology and Infection 2014; Jahrestagung; 4. gemeinsame Kongress DGHM/VAAM CY - Dresden, Germany DA - 2014-10-05 PY - 2014 AN - OPUS4-32166 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kindzierski, V. A1 - Raschke, Silvia A1 - Knabe, Nicole A1 - Siedler, F. A1 - Scheffer, B. A1 - Pflüger-Grau, K. A1 - Pfeiffer, F. A1 - Oesterhelt, D. A1 - Marin-Sanguino, A. A1 - Kunte, Hans-Jörg T1 - Osmoregulation in the halophilic bacterium halomonas elongata: A case study for integrative systems biology N2 - Halophilic bacteria use a variety of osmoregulatory methods, such as the accumulation of one or more compatible solutes. The wide diversity of compounds that can act as compatible solute complicates the task of understanding the different strategies that halophilic bacteria use to cope with salt. This is specially challenging when attempting to go beyond the pathway that produces a certain compatible solute towards an understanding of how the metabolic network as a whole addresses the problem. Metabolic reconstruction based on genomic data together with Flux Balance Analysis (FBA) is a promising tool to gain insight into this problem. However, as more of these reconstructions become available, it becomes clear that processes predicted by genome annotation may not reflect the processes that are active in vivo. As a case in point, E. coli is unable to grow aerobically on citrate in spite of having all the necessary genes to do it. It has also been shown that the realization of this genetic potential into an actual capability to metabolize citrate is an extremely unlikely event under normal evolutionary conditions. Moreover, many marine bacteria seem to have the same pathways to metabolize glucose but each species uses a different one. In this work, a metabolic network inferred from genomic annotation of the halophilic bacterium Halomonas elongata and proteomic profiling experiments are used as a starting point to motivate targeted experiments in order to find out some of the defining features of the osmoregulatory strategies of this bacterium. This new information is then used to refine the network in order to describe the actual capabilities of H. elongata, rather than its genetic potential. KW - Halomonas elongata KW - Systems biology KW - Flux balance analysis KW - Proteomic analysis PY - 2017 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-391172 DO - https://doi.org/10.1371/journal.pone.0168818 SN - 1932-6203 VL - 12 IS - 1 SP - Article e0168818, 1 EP - 22 AN - OPUS4-39117 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Knabe, Nicole T1 - Genetic manipulation of the rock-inhabiting model fungus Knufia petricola A95 N2 - We study the role of protective pigments in stress resistance of the non-pathogenic rock-inhabiting fungus Knufia petricola strain A95. In this context several pigment knock-out mutants have been produced. T2 - Mycological Seminar BAM / RKI CY - Berlin, Germany DA - 20.07.2017 KW - Pigment mutant KW - Back yest PY - 2017 AN - OPUS4-41858 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Knabe, Nicole T1 - Genetic manipulation of protective pigments in a rock-inhabiting model fungus Knufia petricola A95 N2 - Black ascomycetous microcolonial fungi are persistent inhabitants of rock surfaces, but are especially conspicuous in hostile environments like cold and hot deserts. The unique robustness of MFCs is supported by protective pigments, like melanin and carotenoids. We study the role of these pigments in the stress resistance of the model rock fungus Knufia petricola (Chaetothyriales) strain A95. T2 - 13th European Conference of Fungal Genetics CY - Paris, France DA - 03.04.2016 KW - MCF KW - EPS KW - Pigments PY - 2016 AN - OPUS4-37969 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Voigt, Oliver A1 - Knabe, Nicole A1 - Nitsche, Sarah A1 - Erdmann, Eileen A1 - Schumacher, Julia A1 - Gorbushina, Anna T1 - An advanced genetic toolkit for exploring the biology of the rock‑inhabiting black fungus Knufia petricola N2 - Microcolonial black fungi are a group of ascomycetes that exhibit high stress tolerance, yeast-like growth and constitutive melanin formation. They dominate a range of hostile natural and man-made environments, from desert rocks and salterns to dishwashers, roofs and solar panels. Due to their slow growth and a lack of genetic tools, the underlying mechanisms of black fungi’s phenotypic traits have remained largely unexplored. We chose to address this gap by genetically engineering the rock-inhabiting fungus Knufia petricola (Eurotiomycetes, Chaetothyriales), a species that exhibits all characteristics of black fungi. A cell biological approach was taken by generating K. petricola strains expressing green or red fluorescent protein variants. By applying: (1) traditional gene replacement; (2) gene editing and replacement via plasmid-based or ribonucleoprotein (RNP)-based CRISPR/Cas9, and (3) silencing by RNA interference (RNAi), we constructed mutants in the pathways leading to melanin, carotenoids, uracil and adenine. Stable single and double mutants were generated with homologous recombination (HR) rates up to 100%. Efficient, partially cloning-free strategies to mutate multiple genes with or without resistance cassettes were developed. This state-of-the-art genetic toolkit, together with the annotated genome sequence of strain A95, firmly established K. petricola as a model for exploring microcolonial black fungi. KW - Subaerial biofilms KW - Biodeterioration KW - Fluorescent microscopy KW - CRISPR/Cas9 KW - RNA interference PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-518601 DO - https://doi.org/10.1038/s41598-020-79120-5 VL - 10 IS - 1 SP - 22021 PB - Springer Nature AN - OPUS4-51860 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 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-549025 DO - https://doi.org/10.1038/s41529-022-00253-1 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 - CHAP A1 - Breitenbach, Romy A1 - Toepel, Jörg A1 - Dementyeva, Polina A1 - Knabe, Nicole A1 - Gorbushina, Anna ED - Flemming, H.-C. ED - Neu, T. R. ED - Wingener, J. T1 - Snapshots of fungal extracellular matrices N2 - Fungal extracellular materials reinforce a constant interaction between their cell wall and the environment. A dynamic mixture of chitin, glucans, mannans, glycoproteins, glycolipids and pigments supports the success of all fungal life styles – from symbiotic to the free-living and pathogenic. Fungi are perfectly adapted to grow on surfaces and in porous environments, where they form medically and geochemically relevant biofilms. Fungal EPS are critical in adhesion to other fungi, other cells or substratum as well as in the following interaction with the host immune system or material they attack, degrade and deteriorate respectively. Characterisation of extracellular compounds and understanding of its function is necessary to limit damage caused by fungal activity. All necessary methodology from chemical characterization to complete genetic analyses has been developed for medically important fungi. Now it is time to apply this knowledge to the numerous, largely aerobic and very active organisms that occupy a wide range of atmosphere-exposed habitats in the upper lithosphere. One can expect that analogies between medically- and environmentally-relevant model fungal species will help us to address the dynamics of the fungal cell EPS matrix in much more efficient and widely applicable ways. KW - Fungal cell wall KW - Melanin KW - Fungal life styles KW - Environmental and pathogenic fungi KW - Model fungal biofilms KW - Biogenic weathering PY - 2016 SN - 9781780407418 SN - 9781780407425 DO - https://doi.org/10.2166/9781780407418 SP - Chapter 14, 269 EP - 299 PB - IWA Publishing CY - London, UK AN - OPUS4-38094 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -