Effects of pH value and dissolved oxygen on polysaccharide production of Grifola frondosa by submerged fermentation

The effects of pH value and dissolved oxygen(DO) on the production of Grifola frondosa polysaccharides were studied.The result showed that both pH value and DO had significant impacts on the production of mycelium,intracellular and extracellular polysaccharides.The optimized fermentation parameters were determined as follows: DO 75%,pH value 5.1(0h ～ 96h) and pH value 4.2(96h ～ 160h).Under above conditions,the yields of mycelium,intracellular and extracellular polysaccharides increased by 23.02%,28.95% and 25.95%,respectively,indicating the optimized process was feasible.