Abstract: The specific objectives of the study were to determine the optimal culture conditions of Se-accumulation and antioxidant activity of polysaccharide from Auricularia auricula mycelia in order to provide some references for liquid fermentation of Auricularia auricula and industrialization of its polysaccharide production. The single factor and orthogonal experiment was used to get the optimal culture conditions of Auricularia auricula by Se-accumulation of mycelia. The free radical scavenging activity of DPPH (1,1-phenyl-2-hydrazide) was used as the index to study the antioxidant activity of polysaccharide from Auricularia auricula mycelia. The results showed that the optimal culture conditions were as follows: glucose 20 g·L^-1, yeast extract 2.5 g·L^-1, selenium concentration 7.5 μg·mL^-1, pH 6.5,temperature 28 ℃, rotational speed 140 r·min^-1, and cultivation 5 d. Se-accumulation under the optimal culture conditions was 853.16 μg·g^-1,which was 66% higher than that of the original conditions. The antioxidant activity of polysaccharide from Auricularia auricula mycelia in scavenging DPPH radical was 76.12%. Se-accumulation of Auricularia auricula was obviously improved with the optimal culture conditions.

Key words: Auricularia auricula, liquid fermentation, selenium accumulation, polysaccharide, antioxidant activity