The Study On The Souring Cultivation Of Mushroom To Select High-Yielding Strauns Of Exopolysaccharid From Lentinus Edodes And Antioxidant, Antimicrobial Activity

Lentinula edobes is one of the most important edible and medicinal mushrooms, which has attracted much attention due to its immunomodulatory, antitumor and antioxidant function. L. edodes, commonly known as the Shiitake Mushroom, is the world’s second most cultivated mushroom (after the button mushroom). This study was isolated from 20 strains of wild and cultivated mushrooms, screened strain producing with exopolysaccharide, fermentation optimization, antioxidant activity and antimicrobial activity and other aspects of the preliminary study, in order to inhibit fungal EPS antioxidant and antimicrobial research offers ideas and methods, but also for the development and utilization of lentinan as antioxidant and antimicrobial ingredients to provide a theoretical basis. The method was proper and the main contents and conclusions are listed as following:The present study examined the difference of growth rate, sturdy level, dry weight, density and diameter of mycelium among 20 strains of L. edodes. Three strains Le06, Le10, Le16 and Le19 with good results in the previous tests were selected for the further content analysis of the days from inoculation to fruiting, yield, biological efficiency were studied. The results showed that the strain of Le10 is the best in the 20 tested strains. The results showed that the maximum EPS yield was 0.78 mg/mL and biomass was 0.98mg/mL,The effects of different fermentation conditions for mushrooms deep fermentation. The results showed that the culture temperature 25℃, initial pH 5.5 naturally, inoculum 10%,250mL liquid volume 100mL shake flask conditions, mushrooms submerged fermentation of biomass and exopolysaccharide production max. Also investigated different carbon and nitrogen sources for the fermentation of mushrooms, combined with polysaccharides yield and the actual industrial production, agricultural waste select glucose and soybean meal is a suitable carbon and nitrogen sources, actual production has a certain significance. Further orthogonal experiment to determine the best mushroom submerged fermentation medium consists of:2% glucose, soybean meal 2%, KH2PO4 0.1%, MgSO4.7H2O 0.025%, based on the best medium to validate the resulting combination of the above analysis, the results fungus balls dry weight 1.32 mg/mL, compared to the previous optimization improves 34.69%. The maximum exopolysaccharide yield was 1.02 mg/mL, compared to the previous optimization improved 30.77%.Inspected the capability of antioxidation from L. edodes of exopolysaccharide though three kinds of methods were applied including DPPH and the ability of scavenging hydroxyl radical, Superoxide radical scavenging activity. The results showed that L. edodes of exopolysaccharide had relatively better antioxidant capacity. Then studied the antibacterial activity of L. edodes of exopolysaccharide and its stability. The results show mushroom exopolysaccharide conditions at pH 5-9, have antibacterial activity, which is 6 in PH strongest antibacterial activity, indicating that the strain has a wide antibacterial spectrum of pH. Meanwhile, the mushroom exopolysaccharide has good thermal stability, even at 121℃ for 30min still has good antibacterial activity; in order to provide reference basis for the further applications of exopolysaccharide from L. edodes.