Submerged and solid-state cultivation of bioactive extra- and intracellular polysaccharides of medicinal mushrooms Ganoderma lucidum (W. Curt.: Fr.) P. Karst. and Grifola frondosa (Dicks.: Fr.) S. F. Gray (Aphyllophoromycetideae).
Original strains of Ganoderma lucidum (MZKI G97) and Grifola frondosa (GF3) isolated from Slovenian forests were cultivated using submerged and solid-state cultivation. In G. lucidum after 14 days of submerged fed-batch cultivation, up to 17.0 g L-1 dry fungal biomass was produced. Extracellular (1.7 g L-1) and intracellular (0.45 g L-1) polysaccharide fractions were isolated, while in 18 days of solid-state cultivation, 5.77 mg/g of extracellular and 1.45 mg/g of intracellular polysaccharide were produced at the end of the cultivation period. In 28 days of submerged cultivation of G. frondosa, 3.65 mg L-1 of extracellular and 1.30 mg L-1 of intracellular polysaccharide were produced. In 38 days of solid-state cultivation, 3.80 mg/g of extracellular and 0.70 mg/g of intracellular polysaccharide were produced. Polysaccharides were further separated by ion-exchange, gel, and affinity chromatography. The isolated polysaccharides were mainly β-D-glucans. Immunostimulatory effects of isolates were tested for induction of cytokine (TNF-α and IFN-γ) synthesis in human peripheral blood mononuclear cells (PBMC) isolated from buffy coat.