Abstract: The main purpose of this study was to increase the yield of mycelial polysaccharides from Dictyophora indusiata using a large-scale production process. Using a combination of one-factor-at-a-time method and response surface methodology with Box-Behnken design, the optimum medium formulation for the submerged fermentation of D. indusiata was determined as follows: glucose 32.3 g/L, yeast powder 4.5 g/L, potassium dihydrogen phosphate 2.1 g/L, and magnesium sulfate 2.5 g/L. The predicted yield of intracellular polysaccharides was 1.23 g/L, which was close to the experimental value from shake flask fermentation (1.19 g/L). The yields of intracellular polysaccharides in 5-, 30- and 50-L fermentors were 1.43, 1.28 and 1.26 g/L, respectively, which were 16.26%, 4.06% and 2.43% higher than the predicted values, respectively. In this study, the optimized fermentation process gave a high yield of intracellular polysaccharides. Thus, this process provides a good basis for the large-scale production of D. indusiata mycelial polysaccharides.

Key words: Dictyophora indusiata polysaccharide, mycelium, fermentation process, optimization, large-scale production