Biological activities of newly isolated Antarctic fungi: a preliminary study in view of a biotechnological exploitation

Hostile environments serve as intriguing reservoirs of microorganisms possessing largely unexplored metabolic capabilities. The adaptability of extremophiles has captivated the interest of numerous researchers, particularly in the case of fungi thriving in Antarctic conditions. A possible mutualistic symbiosis with fungal endophytes has been proposed as a potential mechanism facilitating the colonization of Maritime Antarctica by plants. In this study, we delved into the endophytic fungal community associated with the leaves of Colobanthus quitensis, an Antarctic plant species capable of thriving in the extreme environment. Multiple strains were isolated and identified, predominantly falling within the Basidiomycota division. The Antarctic fungi were initially characterized for their enzymatic activities (amylase, cellulase, lipase, protease, and pectinase) through assays conducted in both solid and liquid media. No antimicrobial properties against a panel of representative bacterial pathogens were detected in exhausted broth. We also assessed the biological effects of extracts from three fungal isolates on human neuroblastoma SH-SY5Y and bronchial epithelial HBEC cell lines. Utilizing a viability assay, we observed that the SH-SY5Y cell line exhibited greater susceptibility to inhibition compared to the HBEC line, irrespective of exposure time. We also examined the impact of selected Antarctic strains on tomato plants, serving as a model system, to unravel their influence on plant growth. The findings suggest that the Antarctic endophytic fungi hold promise for diverse applications in industrial, agricultural, and medical processes, potentially serving as a reservoir of valuable bioactive compounds.