Fermentation of Lyophyllum decastes and Extraction of Polysaccharides from Mycelia by Enzymatic Hydrolysis

The mycelial growth,intro-and extro-polysaccharide production of Lyophyllum decastes were investigated in this research using a 10 L fermentor,and the effects of six enzymes on extraction of mycelial intro-polysaccharide were also studied.The results indicated that under conditions of 25℃,120 r/min and 200L air flux /h,the content of intro-polysaccharide and yield of extro-polysaccharide could reach the highest on day 8th with 63.1 mg/g dry mycelium and 3.54 g/L,respectively.But,the yields of mycelia and intro-polysaccharide could reach the maximum on the 9th day with 17.86 g/L and 1.11 g/L,respectively.These yields were significantly higher than that by using shaking flask.Among the 6 tested enzymes,the highest yield was obtained by lywallzyme for intro-polysaccharide extraction from mycelia,whereas neutral protease was the most economic enzyme.Comparing with hot-water treatment,the extraction rate was increased by 459.29% and 376.11%,respectively for lywallzyme and neutral protease.The optimal condition for preparation of mycelial polysaccharide by neutral protease was using 1% enzyme,incubated for 2 h at 30℃ during hydrolytic reaction,then followed by 2 times of the same steps for extraction at 95℃,each time for 2 h.