Experimental analysis on the effect of addition of Rhizoma gastrodiae on mycelia and exopolysaccharide productions by submerged culture of Grifola frondosa

Abstract

The effect of addition of Rhizoma gastrodiae on mycelia and exopolysaccharide production by submerged culture of Grifola frondosa was investigated. About 7% (v/v) of R. gastrodiae extract was added to the basal medium used for its biomass and exopolysaccharide productions. The biomass and exopolysaccharide productions reached a maximum of 2.0630±0.0520 g/L and 89.3846±3.2422 mg/L, respectively after day 10 and 8 of cultivation. G. frondosa was sensitive to R. gastrodiae, and there was a reduction in the cycle of exopolysaccharide synthesis. The pH variation in culture provided an indirect inference to this stimulating effect of R. gastrodiae extract addition. Moreover, a curve fitting and parameter analysis was carried out to assay the increasing effect on biomass and exopolysaccharide productions. Meanwhile, the kinetics parameters predicted through the fitting equations in culture, X0 = 0.1523 g/L, Xm = 2.0630 g/L, µm = 0.4994 d-1, α = 0.0858 and α = -0.0069, further clarified the stimulatory effects of R. gastrodiae extract addition in G. frondosa culture.

Key words: Rhizoma gastrodiae, Grifola frondosa, biomass, exopolysaccharide.