Structural analysis and antioxidant activity of extracellular polysaccharide from Tremella fuciformis conidium cells

Using Tremella fuciformis conidium cells for submerged fermentation is a cost-effective way to harvest bioactive compounds. In this study, we emphasized the structural and functional analysis of extracellular polysaccharides (EPS) extracted from T. fuciformis conidium cells. An EPS high-yield strain tyc63 was selected and a 6-day optimum fermentation period was determined. Crude EPS was extracted and three high molecular weight (5189, 171.6, and 661 kDa) polysaccharides TFP-1, TFP-2, and TFP-3 were isolated and purified. TFP-1 is mainly composed of glucose, xylose, mannose, and fucose, while both TFP-2 and TFP-3 are mainly composed of rhamnose, arabinose, mannose, galactose, and glucose. FT-IR analysis revealed that TFP-1, TFP-2, and TFP-3 have typical polysaccharide structure. The antioxidant assay revealed that the crude EPS, TFP-1, TFP-2, and TFP-3 presented high free radical scavenging activities but low ferric reducing power, suggesting that the EPS produced by liquid fermentation could be used as a potent radical scavenger.