Ten strains of Ganoderma lingzhi were cultured by liquid fermentation to compare the mycelial biomass, the yields and content of extracellular polysaccharides, and monosaccharide composition characteristics. Results indicated that the mycelial biomass increased with extending culture period, however, different strains showed a difference in the content of intracellular polysaccharide and the yields of extracellular polysaccharide. Extracellular crude polysaccharide yields of two strains, G0023 and G0160, reached 3.02 and 3.14 g/L in seven days, and polysaccharide content was 84.11% and 91.03%, respectively. G0023 and G0160 could be regarded as excellent strains for producing extracellular polysaccharides. Analysis of ethanol fractional precipitated extracellular polysaccharides showed that the yields and polysaccharide content of 20E fractions (precipitated with 20% ethanol) were higher than those of 50E fractions (precipitated with 50% ethanol), indicating that the fermentation broth mainly contained high molecular weight polysaccharide fractions. 20E fractions were composed principally of glucose with small amount of xylose and mannose. 50E fractions mainly contained glucose and mannose together with small amount of xylose and galactose. Dependence of the apparent viscosity on the shear rate analysis for culture broth of different strains showed that culture broth exhibited non-Newtonian fluid and shear-thinning behavior. The values of apparent viscosity were positively correlated to the yields and polysaccharide content of 20E.
Gao, K., et al. (2019). “Screening of extracellular polysaccharide high-yielding strains of Ganoderma lingzhi in liquid submerged fermentation and polysaccharide characteristic analysis.” Mycosystema 38(6): 886-894.