Combined Mutation Of Cordycepsmilitarisand Optimization Of Fermentation Conditions For Cordycepin Production

Cordycepin is one of the most important metabolites of Cordyceps militaris.It has anti-viral,anti-tumor growth,interference with human RNA and DNA synthesis and other pharmacological effects.At present,although the technical system for cultivated Cordyceps militaris is quite mature,people are confused about the use of strains.In the actual cultivation,there are often problems such as degradation of bacteria,failure to produce grass,and low yield.Therefore,it is necessary to conduct research and breeding of the species of Cordyceps militaris.In this experiment,a high-yield cordycepin strain was screened by combined mutagenesis of 60Coy and ultraviolet light,and the conditions of solid-state fermentation and culture were optimized and the fruiting bodies of Cordyceps militaris were studied.The following main research results have been obtained:(1)The experimental strain of Cordyceps militaris C-8 was used as the starting strain of the mutagenized strains in Anhui University,and treated with 60Co ?radiation.The positive mutation rate and lethality rate were taken as the evaluation indexes.The optimal irradiation dose was 100 Gy.(2)The second mutagenesis was performed with a UV lamp(25 W)for 20,40,60,80,100,120 s.The optimal irradiation time was 80 s using two indicators of positive mutation rate and lethality of mutagenized strains.Compound induction was achieved in strain C1-7 with a cordycepin content of 7.376 mg/g which was 79%higher than that of C-8 strains.The genetic stability test was carried out,and cordycepin production was stable after subculture for 12 generations.(3)The optimal solid culture conditions for selection were:soluble starch 15%,yeast extract 3%,pH 5.5,initial moisture content 64%,fermentation time 13 days,early temperature 24 ?,and late temperature 21 ?.Produce cordycepin for large-scale solid fermentation has a good reference.(4)C1-7 bottled cultivation test results:fresh weight 55.74 g,dry weight 7.998 g,biological efficiency 69.97%,cordycepin content of 12.679 mg/g than the strain C-8 cordycepin content increased 100.2%,determined to be Better strains.