Studies On Submerged Fermentation And Polysaccharide Function By Agrocybe Aegirit

The submerged culture medium, fermentation conditions, extractions of intracellular and extracellular polysaccharides, purification, ingredient analysis and immunity function of Agrocybe aegirit were studied on the paper.Influences on dry weight of mycelia and the production of extracellular polysaccharides of Agrocybe aegirit, which were caused by different carbon sources and nitrogen sources, were studied with shake flask culture method. The results showed that the best carbon source for Agrocybe aegirit submerged fermentation was corn powder, the best nitrogen source was yeast powder. The medium components for submerged fermentation was optimized throught orthognal test. The results showed the best medium was composed by corn powder 2%, yeast powder 0.3%, KH₂PO₄ 0.2%, MgSO₄ 0.05%. The best conditions was 25℃, 60mL/250mL shake flasks, 150r/min, the inoculation volume was 15%, the nature PH, 5 days.The effects of various conditions of extraction on the polysaccharides of Agrocybe aegirit was investigated. The optimum extractive condition of intracellular polysaccharides was determined through single factor test as follows: extracting temperature 80℃-90℃; water mycelia ration 4:1; extracting time: 10 hours; extracting 3 times; precipitated by addition of 3 volumes of 95% ethanol. Optimized process of precipitated by ethanol for extracellular polysaccharides through response surface analysis. The results indicated that with addition of 4 volumes of 95% ethanol, precipitated 17h, PH 5.5 conditions,the yield of extracellular polysaccharides was about 5.76mg/ml.The ordinary common nutrition ingredient analysis showed that the fermentation mycelia and thalli of Agrocybe aegirit contained protein and carbohydrate to a similar level. The whole amino acid analysis showed that the fermentation mycelium, fermentation, thalli all contained 17 kinds of anino acid. The amino acid component and proportion in mycelia and thalli were similar.