Investigation of Submerged Fermentation Parameters of Ganoderma Strain G7 of High Yield Intracellular Polysaccharide

The strain G7 was screened out from 22 Ganoderma strains collected from various regions according to the yield of intracellular polysaccharide.The optimum fermentation conditions were studied by single factor experiment and orthogonal test.The optimum parameters of carbon source,nitrogen source,initial hither medium volume in the flask and cell density were obtained.In addition,the metabolic curves of intracellular polysaccharide,extracellular polysaccharide,biomass and the pH change of medium were determined.It was found that the optimal fermentation time was depended on the objective product.Most of the intracellular polysaccharide was produced within the former stage of fermentation.The yield of intracellular polysaccharide was up to 0.533 g/100 mL medium at the 60th hour.