Optimization for the production of exopolysaccharides from Morchella esculenta SO-02 in submerged culture and its antioxidant activities in vitro

摘要

The aims of this work were to optimize the conditions for exopolysaccharides (EPS) production by Morchella esculenta SO-02 in submerged culture, and to evaluate the antioxidant activities of EPS in vitro. The optimal medium constituents were determined as follows (g/1): bran 200, glucose 30, yeast extract 1, KH2PO4 2 and MgSO4·7H2O 1.5. The optimum parameters of liquid culture were temperature 25 °C, cultivation time 4d, the volume of medium 100 ml, rotary speed 200 rpm and initial pH 6.5, respectively. Under the optimized conditions, the values of dry cell weight (DCW) and EPS were 9.2 ±0.7 g/1 and 2913 ± 262 mg/1, respectively, which were 42 ± 3% and 100 ± 1% higher than those in basal liquid medium, respectively. The EPS demonstrated positively antioxidant potential on superoxide anion radical scavenging, reducing power and hydroxyl radical scavenging.