SINOPSIS

The effect of culture conditions on growth and polysaccharide production by Lentinus edodes, L. lepideus, and L. tigrinus was investigated. These fungi accumulated 11.2−14.0 g/L biomass, 2.0−5.0 g/L exopolysaccharides, and 4.0%−10.2% endopolysaccharides on optimal glucose-peptone media. The maximum amount of endopolysaccharides (9.5%−10.2%) was found in L. lepideus biomass, whereas the highest level of exopolysaccharide synthesis (4.5−5.0 g/L) was observed in L. edodes. The specific growth rate of the fungi (μ) equaled 0.010 g/L for L. edodes, 0.020 g/L for L. lepideus, and 0.025 g/L for L. tigrinus; productivity of exopolysaccharide synthesis: 550, 300, and 500 mg/L per day, respectively; and productivity of endopolysaccharide synthesis: 40, 170, and 140 mg/L per day respectively. Fungal polysaccharides combined both high-molecular-weight fractions (Mr = 200−2000 kDa) and low-molecular-weight fractions (Mr < 10 kDa). As to carbohydrate composition, polysaccharides of investigated fungi were identified as heteroglycans, with glucose as the dominant monomer and minor amounts of arabinose, galactose, xylose, and mannose. For physical-chemical properties, a close similarity was shown between the polysaccharides of L. tigrinus and L. edodes.