Abstract:

Matarhizium taii, the anamorph of edible medicinal mushroom Cordyceps taii, can produce polysaccharide with diverse pharmacological effects for the development of functional foods and new drugs. The purpose of this study was to investigate the use of a combinatorial experimental strategy, involving both one-factor-at-a-time and orthogonal array design methods to optimize the fermentation medium composition for active polysaccharide production by submerged fermentation of Matarhizium taii. The results showed that the optimal medium composition for active polysaccharide production consisted of xylose 40 g/L, soybean steep liquor 4 g/L, (NH4)2SO4, 0.2 g/L vitamin A plus D 1 g/L, KH2PO4 1 g/L and MgSO4·7H2O 0.5 g/L at initial pH 6.0. Using such a medium, an exocellular polysaccharide yield of up to (22.72 ± 0.55) g/L was obtained, which was over 30 times higher than that obtained using fermentation basal medium.

Key words: Metarhizium taii, polysaccharide, medium optimization