TY - CONF A1 - Rabin, Ira T1 - Unveiling the use of writing materials in Carolingian manuscripts N2 - After having been neglected for a long time, materiality is nowadays of great interest in the study of manuscripts. This allows us to explore the variety (and potential coexistence) of different inks and pigments in type and composition in their use over time and geographical area. In this presentation, we aim to contribute to their study through archaeometric analyses of black and red inks used in Carolingian manuscripts copied between the 8th and the 10th centuries. These analyses are based on an interdisciplinary strategy, bringing together knowledge from the humanities and natural sciences to understand the global use of black and red inks in the Carolingian Empire. In this regard, we adopted a non-invasive protocol that included near-infrared imaging and X-ray fluorescence spectroscopy for on-site measurements supported by historical and palaeographic analysis. The results have been collected in the framework of two projects at the University of Hamburg in close collaboration with the Bundesanstalt für Materialforschung und -prüfung, Berlin (BAM) and will be compared with several other archaeometric studies of contemporary manuscripts. T2 - Novel approaches to Digital Codicology CY - Tours, France DA - 10.05.2023 KW - Carolingian manuscripts KW - Historick inks KW - Pigments PY - 2023 AN - OPUS4-61199 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schumacher, Julia T1 - The roles of DHN melanin and the stress-activated MAP kinase in the rock inhabitant Knufia petricola N2 - Black fungi/yeasts exhibit high stress tolerance, yeast‑like or meristematic growth, and constitutive 1,8-dihydroxynaphthalene (DHN) melanin formation. Due to their slow growth, robust cell walls and the lack of sexual cycles and genetic tools, the underlying mechanisms of their phenotypic traits have remained largely unexplored. Using recently developed genetic tools, it is now possible to manipulate the genome of the rock-inhabiting model fungus Knufia petricola. Thus, gene functions and the cell biology of black fungi can be studied using CRISPR/Cas9-based genome editing and live-cell imaging with genetically encoded fluorescent proteins. Here, we are addressing the question to which extent constitutive pigment formation (melanin and carotenoids) and responses mediated by the stress-activated mitogen-activated protein (MAP) kinase contribute to the observed extremotolerance of K. petricola. The mutations of pks1, phs1 and both genes result in melanin-free (pink), carotenoid-free (black) and pigment-free (white) strains, respectively. The other putative melanogenic genes were identified in the genome, deleted to confirm their involvement in DHN melanogenesis and co-expressed in Saccharomyces cerevisiae for reconstruction of the synthesis pathway. Sak1 encoding the stress-activated MAP kinase was deleted in the wild-type and different pigment-deficient backgrounds. Growth of the obtained single, double and triple deletion mutants was tested by droplet tests on media supplemented with different stress-inducing agents. The Δsak1 mutants show slightly reduced growth rates even without environmental pressure and are hypersensitive to different stresses: e.g. osmotic, oxidative, membrane, pH and heat stress. Melanin-free Δsak1 mutants are more sensitive than black Δsak1 mutants to some but not all stress conditions, suggesting that melanin and the SAK1 pathway have complementary roles in protecting K. petricola from stress. T2 - 16th European Conference on Fungal Genetics CY - Innsbruck, Austria DA - 05.03.2023 KW - Black fungus KW - Extremotolerance KW - Pigments PY - 2023 AN - OPUS4-57147 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schumacher, Julia T1 - Fungi in extreme habitats: Lessons from the microcolonial black fungus Knufia petricola N2 - Fungi that share light-flooded habitats with phototrophs may profit from their excess photosynthetic products. But to cope with sunlight-associated stresses [e.g. high temperatures, UV radiation with associated DNA damage, accumulation of reactive oxygen species (ROS), desiccation and osmotic stresses] it is important for fungi to accurately sense and respond to changes in light. The genomes of black [dihydroxynaphthalene (DHN) melanin-containing] fungi from phyllosphere and exposed solid surfaces contain multiple photoreceptors (PRs). The plant pathogen Botrytis cinerea (Leotiomycetes) has a highly sophisticated photosensory and signalling system that helps to avoid light and to locate susceptible hosts. Rock-inhabiting Dothideomycetes and Eurotiomycetes including Knufia petricola possess equal numbers of PRs along with the same set of protective pigments. This similarity between black fungi from plant and rock surfaces suggests that photoperception and -regulation are important for fungi that receive nutrients through cooperation with phototrophs. T2 - Gordon Research Conference "Cellular and Molecular Fungal Biology" CY - Holderness, NH, USA DA - 26.06.2022 KW - Light KW - Stress KW - Photoperception KW - Pigments PY - 2022 AN - OPUS4-55249 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -