Abstract:

In order to effectively exploit rice bran for preparing health food containing polysaccharides through mimic solid fermentation, rice bran was used as the culture medium matrix to explore the effects of water content, peptone, glucose and pH on solid fermentation of Grifola frondosa. The optimal culture medium and fermentation conditions were explored by single factor and orthogonal experiments on the basis of grifolan productivity. Results indicated that the optimal medium formula was composed of rice bran as solid culture medium matrix with 65% water, 0.5% peptone, 4% glucose (by mass of rice bran) and pH 5.5. The optimal fermentation conditions were 20 g rice bran matrix in a 250 mL fermentation flask, inoculation amount of 10%, fermentation temperature of 25 ℃, rotation speed of 170 r/min and fermentation time of 11 days. The yield of grifolan was 4.52% under the optimal conditions. By calculating with SPSS software, a regression model of total grifolan was achieved.

Key words: rice bran medium, solid fermentation, grifolan, regression model