The Study On The Souring Cultivation Of Mushroom To Select High-yielding Strains Of Lentinus Edodes (Berk) Sing Exopolysaccharide And Antioxidant Activity

This study selected five mushrooms to screen lentinula edodes strains, aiming at selecting high-yielding strains of Lentinus edodes polysaccharide from both mycelial biomass and broth polysaccharides then the content of mushrooms should be screened for strains 1363A. The results showed that the best strains producing polysaccharides was 1363A, screening a exopolysaccharides of carbon and nitrogen, the composition of the liquid medium was determined, results showed that the optimal carbon source was glucose, the optimal nitrogen sources were peptone. Finally determined the medium composition as follows: peptone 1%, glucose 2%, KH2PO4 0.3%, MgSO4 7H2O 0.15%, VB1 8mg/1000ml, culture temperature 25℃, shaker speed 120rpm, loaded liquid 100ml/250ml, vaccination 0.50cm2 block volume strain, fermentation time 10d. Under these conditions, 1363A mycelial biomass and extracellular polysaccharide content were 0.909 and 0.66, respectively.Under the best conditions of medium ratio to extract bacterial polysaccharide fermentation broth by alcohol extraction , extraction rate was88.5%, then the analysis of the results of its physical and chemical properties showed that: 1363A Polysaccharide's properties, which were light yellow powder, soluble in water, easy to absorb moisture, non-starch, non-reducing sugars and non-sugar acid.In the study of antioxidant activity had verified that the 1363A had a certain antioxidant activity, the experiment had made a preliminary identification of what the rate of 1363A scavenged superoxide anion radical and hydroxyl radical, results showed that the 1363A on the superoxide anion radical and hydroxyl radical scavenging rates were 34.5% and 53.2%.