关键词: 荷叶离褶伞;液体发酵;生物酶;多糖提取

Abstract:

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.

Key words: Lyophyllum decastes, submerged fermentation, enzymatic hydrolysis, polysaccharide extraction