Abstract

Medicinal mushrooms have profound health-promoting benefits. Polysaccharides constitute an important percentage of fungal biomass, where the hyphal wall frequently contains more than 75% of polysaccharide. Trametes versicolor is a medicinal fungus producing exopolysaccharides (EPS). The media were tested with different carbon and nitrogen sources which maximize the production of EPS by T. versicolor. The media were optimized with different carbon (glucose, fructose, sucrose, maltose, lactose, raffinose, mannitol and xylose) and nitrogen sources (peptone, glycine, gelatin, casein, yeast extract, ammonium sulphate, KNO₃ and NaNO₂) for the higher yield of polysaccharides. Biomass, pH changes along with the EPS production of the broth were followed during fermentations lasting 7 and 14 days. Fructose (8 g. dr. w/l) was shown to have yielded the highest production of EPS for 7 days, and gelatin (11 g. dr. w/l) to have produced the highest biomass. An experimental design to do this was adopted, in which the effects of pH were considered.

Key words: Basidiomycetes, exopolysaccharide, biomass, submerged culture.