Biological activities of a polysaccharide from the coculture of Ganoderma lucidum and Flammulina velutipes mycelia in submerged fermentation

Abstract A polysaccharide was obtained through the coculture of Ganoderma lucidum and Flammulina velutipes mycelia in submerged fermentation. Compared to G. lucidum monoculture, the coculture decreased cell biomass production and increased the exopolysaccharides (EPS) yield. In addition, the coculture EPS presented comparable antioxidant activity, however, enhanced anti-inflammatory activity. Under normal cultivation conditions, the coculture EPS displayed greater than 95 % cell viability to the hTERT-immortalized foreskin fibroblast cells. After UV irradiation, the coculture EPS presented less cytotoxicity than G. lucidum EPS when EPS concentration was 1.5 and 3.0 mg/mL. After serum starvation, the difference in the viability of the fibroblast cells treated by monoculture and coculture EPS was insignificant. Fractionation of the coculture EPS yielded one major fraction with a molecular weight of 1374.6 kDa. FT-IR analysis suggested that there existed both β-glucose and α-galactose in the coculture EPS, yet higher amount of β-glucose.