TY - CONF A1 - Knabe, Nicole T1 - Some like it on the rocks: recurring stresses select for rock-inhabiting fungi with manifold protective pigments N2 - Black ascomycetous microcolonial fungi (MCF) are persistent inhabitants of rock surfaces in deserts as well as ubiquitous in other wide-spread terrestrial ecosystems including man-made materials such as solar panels. The ability of MCF to cope with multiple, rapidly fluctuating stresses makes the group an interesting subject in the study of stress resistance. Carotenoids and melanin are amongst the protective pigments that contribute to the robustness of MCF. We studied their role in stress resistance of the non-pathogenic rock-inhabiting fungus Knufia petricola (Chaetothyriales) strain A95. Disruption of melanin synthesis affects not only oxidative-stress resistance but also the extracellular polysaccharide (EPS) matrix and lipid composition of the cell membrane. T2 - 29th Fungal Genetics Conference CY - Pacific Grove, USA DA - 14.03.2017 KW - Black yeast KW - Cell wall KW - Pigment KW - Melanin PY - 2017 AN - OPUS4-39671 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Noack-Schönmann, Steffi A1 - Bus, T. A1 - Banasiak, Ronald A1 - Knabe, Nicole A1 - Broughton, William J. A1 - Dulk-Ras, H.D. A1 - Hooykaas, P.J.J. A1 - Gorbushina, Anna T1 - Genetic transformation of Knufia petricola A95 - a model organism for biofilm-material interactions N2 - We established a protoplast-based system to transfer DNA to Knufia petricola strain A95, a melanised rock-inhabiting microcolonial fungus that is also a component of a model sub-aerial biofilm (SAB) system. To test whether the desiccation resistant, highly melanised cell walls would hinder protoplast formation, we treated a melanin-minus mutant of A95 as well as the type-strain with a variety of cell-degrading enzymes. Of the different enzymes tested, lysing enzymes from Trichoderma harzianum were most effective in producing protoplasts. This mixture was equally effective on the melanin-minus mutant and the type-strain. Protoplasts produced using lysing enzymes were mixed with polyethyleneglycol (PEG) and plasmid pCB1004 which contains the hygromycin B (HmB) phosphotransferase (hph) gene under the control of the Aspergillus nidulans trpC. Integration and expression of hph into the A95 genome conferred hygromycin resistance upon the transformants. Two weeks after plating out on selective agar containing HmB, the protoplasts developed cell-walls and formed colonies. Transformation frequencies were in the range 36 to 87 transformants per 10 µg of vector DNA and 106 protoplasts. Stability of transformation was confirmed by sub-culturing the putative transformants on selective agar containing HmB as well as by PCR-detection of the hph gene in the colonies. The hph gene was stably integrated as shown by five subsequent passages with and without selection pressure. KW - DNA transfer KW - Fungal cell-walls KW - Protoplasts KW - Hygromycin resistance KW - Black yeast KW - Sub-aerial biofilms KW - Stress-protective morphology KW - Ancestor of opportunistic pathogens & lichens PY - 2014 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-320840 UR - http://www.amb-express.com/content/4/1/80 DO - https://doi.org/10.1186/s13568-014-0080-5 SN - 2191-0855 VL - 4 SP - 80, 1 EP - 6 PB - Springer CY - Heidelberg AN - OPUS4-32084 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -