Study On Characteristics Of Cordyceps Endophytic Fungi And Fermentation Conditions

This experiment with wild Cordyceps sinensis as the research object, from isolated five strains of fungi were obtained, and the two strains of high yield of Cordyceps plain strain as the experimental strains screened.the fermentation conditions of two different strains isolated from Cordyceps sinensis were optimized by means of orthogonal design.The results were showed as follows:(1) Five strains of fungi were isolated and named as CS-1, CS-2, CS-3, CS-4 and CS-5. CS-2 and CS-5 were higher in the production of Cordycepin.(2)CS-2 can not grow at the pH2.0 and pH10.0.respecttively.The optimum pH 6.0;It can not grow in 10℃ and 35℃, the optimum growth temperature is 20℃;CS-5 can not grow at the pH3.0 and 10.0,the optimum pH was 6.0.And it can not grow at the temperature 5℃ and 35℃, the optimum growth temperature is 20℃(3) The optimum fermentation medium for CS-2 were as follows:Sucrose and Peptone.The optimum fermentation medium for CS-5 were as follows:Sucrose,Yeast and powder.(4) The optimal fermentation condition of CS-2 was:original pH of medium 6.5, inoculums quantity 6%, fermentation temperature 22℃ for 7d.Under this condition, the production of cordycepin reached 0.98mg/mL. The optimal fermentation condition of CS-5 was:original pH of medium 6.5. inoculum quantity 9%. fermentation temperature 20℃ for 6d. Under this condition, the production of cordycepin reached 0.482mg/mL.(5)The content of Cordyceps polysaccharide and mannitol in CS-2 were respectively. 14.537mg/mL,1.039mg/mL; the content of Cordyceps polysaccharide and mannitol in CS-5 were 20.407mg/mL and 0.73mg/mL, respectively.