Abstract:To investigate the bioactive components and their potential utilization of associated fungus of Tremella sanguinea Peng，the strain XE02 of Stereum sp.isolated from the fruiting body of T.sanguinea Peng was used.The liquid fermentation method was employed to obtain fermented polysaccharides from the fermentation broth，which were further subjected to decolorization，deproteinization，and ethanol precipitation to obtain crude extracellular polysaccharides with a yield of（1.1±0.2）g/L.The crude polysaccharides were then purified using DEAE-52 cellulose column chromatography，resulting in a neutral Stereum sp.exopolysaccharide fraction（SEPS）.Fouriertransform infrared spectroscopy analysis showed that SEPS exhibited typical structural features of polysaccharides，with pyranose as the monosaccharide composition and the presence of α and β-glycosidic bonds.Antioxidant activity analysis revealed that SEPS possessed significant hydroxyl radical and superoxide anion radical scavenging abilities，with dose-dependent effects.At a concentration of 10 mg/mL，the scavenging rates were approximately 68% and 74%，respectively.SEPS demonstrated excellent moisture-absorption and moistureretention properties.Under relative humidity conditions of 43% and 81%，SEPS exhibited lower moisture absorption than glycerol but higher than sodium alginate.In a dry silica gel environment（0% relative humidity），SEPS showed better moisture retention than glycerol and sodium alginate.