Diversity of culturable fungi in Antarctic lakes and their potential for producing compounds of biotechnological interest

Abstract

We evaluated the diversity and biotechnological potential of culturable fungi from sediments of Florencia and Katerina lakes, James Ross Island, maritime Antarctica. A total of 57 fungal isolates, belonging to 24 taxa (16 from Florencia and 8 from Katerina) were identified. Ascomycota was the dominant phylum, followed by Mortierellomycota and Basidiomycota. The main genera included Cladosporium, Dactylaria, Glaciozyma, Graphium, Leucosporidium, Mortierella, Penicillium, Pseudeurotium, Pseudogymnoascus, Tetracladium and Thelebolus. Pseudogymnoascus sp. 1 and Thelebolus species were the most frequent. Florencia Lake showed greater taxonomic richness and diversity than Katerina Lake. Of all taxa, 12 were exclusive to Florencia, 4 to Katerina, and 4 were shared. All fungal isolates were screened for the production of 11 industrially relevant enzymes; inulinase was the most common, followed by protease, invertase, gelatinase and pectinase. Eight isolates (Pseudogymnoascus and Thelebolus) produced biosurfactants and 50 contained intracellular lipid bodies. A Penicillium palitans isolate fully inhibited germination of Allium schoenoprasum seeds, and NMR analysis confirmed (-)-palitantin as the active compound. These results confirm that Antarctic lake sediments harbor diverse fungi with potential for producing enzymes, biosurfactants, lipids and bioactive metabolites, reinforcing the value of studying extremophilic fungi as a source of bioproducts in the context of fragile ecosystems affected by climate change.

Keywords: Antarctica; Biosurfactants; Enzymes; Extremophiles; Lipids; Phytotoxins.