Structure and bioactivity of polysaccharide from a subseafloor strain of Schizophyllum commune 20R-7-F01

Fungal polysaccharide is a kind of biomacromolecule with multiple biological activities, which has a wide application prospect and may play an important role in organisms to cope with extreme environments. Herein, we reported an extracellular polysaccharide (EPS) produced by Schizophyllum commune 20R-7-F01 that was isolated from subseafloor sediments at similar to 2 km below the seafloor, obtained during expedition 337. The monosaccharide of EPS was glucose and its molecular weight was 608.8 kDa. Methylation and NMR analysis indicated that the backbone of the EPS was (1 -* 3)-beta-D-glucan with a side chain (1 -* 6) beta-D-glucan linking at every third residue. Bio-active assays revealed that the EPS had potent antioxidant activity and could promote RAW264.7 cells viability and phagocytosis. These results suggest that fungi derived from sediments below seafloor are important and new source of polysaccharides and may be involved in the adaptation of fungi to anoxic subseafloor extreme ecosystem.

Automated summary

An extracellular polysaccharide (EPS) produced by Schizophyllum commune 20R-7-F01, which was isolated from subseafloor sediments, has been reported. The EPS showed various biological activities, including antioxidant activity and promoting cell viability and phagocytosis. These findings suggest that fungi from subseafloor sediments are an important source of polysaccharides and may play a role in the adaptation of fungi to extreme subseafloor ecosystems.