Studies On Strain Screening, Strain Keeping And Liquid Fermentation Of Poria Cocos

P6, a high producing and genetic stable mutant strain was obtained from the original strain PO through the mutagenesis with ultraviolet, eutrophication of auxotrophic strains by differential sterilization and filamentous filtration, and gradual selection in TYEG, plates with different concentration gradient exocellular polysaccharide. The dry weight of filamentous form reached 11.92 gram per liter, which was increased by 7. 58% compared with the original strain PO.Freezing and drying strain keeping , glycerol strain keeping and slant strain keeping were studied through Erlenmeyer flask liquid fermentation and plate culture .The results showed that three strain keeping methods all had good effects.Optium fermentation medium and culture conditions were determined through Erlenmeyer flask liquid fermentation , ampliate liquid fermentation technique was also determined later.Under the total 4% glucose concentration , it was proved to be better that the 1% glucose concentration was added respectively at 60 hour and 72 hour of liquid fermentation. Liquid fermentation in the fermentor was better than Erlenmeyer flask liquid fermentation, because it could decrease liquid fermentation time from 168 hour to 120 hour and increase the dry weight of filamentous form from 10.74 gram per liter to 11.95 gram per liter compared with Erlenmeyer flask liquid fermentation.There were two kinds of Poria cocos polysaccharide in the fermentation liquid.Exocellular polysaccharide reached 5.43 gram per...