TY - CONF A1 - Schumacher, Julia A1 - Brandhorst, Antonia A1 - Erdmann, Eileen A1 - Nitsche, Sarah A1 - Voigt, Oliver A1 - Gorbushina, Anna T1 - DHN melanin synthesis in the rock inhabitant Knufia petricola N2 - DHN (1,8-dihydroxynaphthalene) melanin is produced by different Ascomycetes via slightly differing biosynthetic routes. The polyketide synthases (PKS) release the heptaketide YWA1, the hexaketide AT4HN or the pentaketide T4HN. The first two products are deacetylated by ‘yellowish-green’ hydrolases to T4HN, and T4HN is further converted by a core set of enzymes to DHN. Final polymerization steps are accomplished by multicopper oxidases (MCOs). The involved genes are tightly clustered, partially clustered or widely distributed in the genomes of DHN melanin-producing fungi. DHN melanogenesis is often regulated in a spatial and temporal fashion resulting e.g. in melanized reproduction, survival and/or infection structures. In contrast, a polyphyletic group of Ascomycetes (microcolonial fungi/ black yeast) dwelling in hostile habitats such as bare rock surfaces in hot and cold deserts, exhibits constitutive melanogenesis. Here, we report on the identification and functional characterization of the DHN melanogenic genes of Knufia petricola as a representative of the Chaetothyriales, the sister order of the Eurotiales. Orthologs for all melanogenic genes were identified in the genome of K. petricola A95, including one gene encoding the polyketide synthase (KpPKS1), two genes encoding ‘yellowish-green’ hydrolases (KpYGH1,2), two genes encoding THN reductases (KpTHR1,2) and one gene encoding a scytalone dehydratase (KpSDH1). Ten genes encoding MCOs were identified, all MCOs are predicted to be secreted. The genes are not clustered in the genome but are highly expressed. Gene functions are studied by generation of single, double, and multiple deletion mutants in K. petricola and by heterologous expression in Saccharomyces cerevisiae for reconstruction of the synthesis pathway. T2 - VAAM Fachgruppentagung "Molecular Biology of Fungi" CY - Kaiserslautern, Germany DA - 07.09.2022 KW - DHN melanin KW - Genetics KW - Biodegradation PY - 2022 AN - OPUS4-55676 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -