Fungi of the Arctic Seas

— The abundance and diversity of filamentous fungi in the bottom sediments of the Arctic Ocean seas (the Greenland, Barents, and Kara seas) were studied. Samples of the surface bottom sediments were collected during the 84th (July–August 2021) and 86th (October–November 2021) cruises of RV Akademik Mstislav Keldysh . The taxonomic affiliation of the isolated fungi was determined using polyphasic taxonomy. The isolated fungi belonged to 16 genera of different classes of ascomycetous, basidiomycetous, and zygomycetous fungi. The effect of cultivation temperature and different NaCl concentrations on fungal growth was determined, as well as the effect of cultivation conditions on the fatty acid profile for the strains capable of growth on media with increased osmotic potential. While fatty acid composition was shown to be affected by changes in environmental conditions, the response to osmotic stress differed among the studied cultures from deep-sea sediments.