Liquid Culture Of Cordyceps And The Preliminary Study On Extracellular Enzyme

Cordyceps was a precious traditional Chinese medicine, the active substances had high medicinal value, but the wild resources was very limited, so large-scale submerge culture with fermentor could improve the production of Cordyceps, and the Cordyceps after cultured with wort could be drunk directly, saving the cost of production.Response surface analysis got the best composition of the submerged culture medium for Cordyceps militaris FFCC5124. The results showed that the optimal submerged culture conditions achieved were sucrose 2.74%, beef extract 1.86%, pH is 7.37,under these conditions, maximum productions of mycelia biomass reached 10.2g/L, and the ANOVA of response surface methology showed that first degree(A/B/C) of three factors had great impact on biomass, followed by quadratic term(A×A/B×B/C×C), and interaction terms on the impact of weak biomass; There were lots of starch, protein and cellulose in the wort, in order to prove that these nutrients could be used by Cordyceps, so it determined the activity of extracellular enzymes (amylase, protease and cellulase), in optimal medium and enriched medium respectively by DNS method, the result showed that the activity of enzyme in the enriched medium were higher than in the optimal medium, it was because added some extracellular enzymes inducers in enriched medium, it could induce cell to produce more enzymes; In order to prove the feasibility of submerge culture with fermentor, so the 30L fermentor experiment on a small pilot test, the concentration of residual sugar was determined by DNS method, and the mycelial biomass was determined by mycelium drying. The result showed that the concentration of residual sugar had an obvious rising tendency after continuous culture 36h, biomass had peaked in 108h. The Cordyceps militaris fungal and spore grew very well in the wort.