Study On Fungi Screening And Liquid Fermentation Process Optimized Of Cordyceps Sobolifera

Cordyceps cicadae is a medicinal fungi with a long history, which contains a variety of amino acids, inorganic salts and bioactive substance. With the changes of the natural environment, Cordyceps sobolifera becomes a scarce resource, and this article conduct a study of artificial cultivation of the Cordyceps cicadae from cicadae microbial screening, three good cicadae Strain and cicadae liquid fermentation process optimization. The study results are as follow:1. We made the microorganisms isolated from natural cicadae and get screened fungi cicadae V17, which was identified to be cicada Paecilomyces. To make bacterial strain liquid state fermentation, the biomass obtained as5.25g/L when it is5d. Cordyceps cicadae mycelium crude ingredients were measured, and the moisture content of8.91%, the crude protein content of27.19%,7.79%crude fat, crude fiber content of6.20%, ash content of1.71%, which is close to the composition of the natural cicadas. Determination of biologically active substances in the mycelium of Cordyceps, in which acid content149.52mg/g, the the fungal polysaccharide content is122.02mg/g, which is higher than that in natural cicadae content。2. The use of ultraviolet mutagenesis to fungi V17, the ultraviolet mutagenesis dose is90s, the lethality rate was85%, a higher-yield mycelium strain V17-7is produced, the biomass in the fermentation broth was5.99g/L, an increase of14.10%. Determination of biologically active substance in the V17-7strain mycelium, their mycelia of Cordyceps acid content is197.24mg/g, an increase of31.92%; fungal polysaccharide content of137.24mg/g, an increase of12.48%. And we make the passaged test of the bacterial strain continuously7times, the various numerical values are essentially the same, and genetic stability.3. We carried on a research of the cicada added amount and other conditions in Fungi fermentation medium cicadae C sources, N sources, and we obtained in PDA medium, add2.5%glucose,0.3%peptone, and5%of the cicada can improve the fermentation broth of biomass; by changing the culture temperature in the fermentation process, the size of the inoculum size and the size of the shaker rate of liquid fermentation process optimization, optimal fermentation process is28℃,6%of the inoculum and210r/min shaker rate. Through optimization of the medium and fermentation process, the biomass in the fermentation broth is increased to6.97g/L.