毕业论文-定稿.doc

粘细菌胞外多糖提取纯化及其生物活性检测 摘　　要 　　随着这几年来糖化学的迅速发展，微生物胞外多糖的理论和应用也受到了人们的重视。胞外多糖的提取纯化和组分分析的实验技术都已成熟，为本实验提供了理论基础和实验指导。本文通过观察粘细菌在CAS固体培养基平板上的菌落黏性圈，从79株粘细菌中筛选到6株胞外多糖产量高的菌株，并对其中4株粘细菌产生的胞外多糖进行了提取纯化。粘细菌经液体发酵培养后，将发酵液进行乙醇沉淀得到粗多糖的提取物。粗多糖经氯仿、三氯乙酸脱蛋白，过氧化氢脱色，得到白色粉状纯化物。纯化的粘细菌胞外多糖采用0.5mol/L盐酸水解后，经高效液相色谱分析，可确定菌株92033、93147、94016的胞外多糖中均含有葡萄糖、甘露糖，其他成分需进一步验证。4株粘细菌的胞外多糖纯化物的水溶液，经絮凝活性检测实验表明，均具有絮凝活性，其中菌株92033对4g/L的高岭土悬浊液的絮凝率达到92.84%，显示出良好的应用前景。 关键词：糖化学　　胞外多糖　　粘细菌　　絮凝活性 ABSTRACT As the rapid development of sugar chemical over the past few years, the theory and application of the microbial exopolysaccharides were important for the people. The extraction, purification and component analysis experimental technique of the exopolysaccharide had been mature, which provided a theoretical basis and experimental guidance. In this article, Myxobacteria which produced many polysaccharide were screened from the CAS solid medium by observing the stickiness of colony. We had got six strains which could produced high exopolysaccharide from the 79 strains, and four strains had been extracted and purificated. After liquid culture fermentation, we could obtained the crude polysaccharide extracts by alcohol precipitation methd from the fermentation broth. We obtained the white powder of the polysaccharide by the chloroform and trichloroacetic acid removing protein and hydrogen peroxide detreated. After purified Myxobacteria exopolysaccharides 0.5mol/L hydrochloride hydrolysis, we could determine that the strains of 92033,93147,94016 which containing glucose and mannose by high performance liquid chromatography analysis. Other components were proved by further validation. After the testing of the flocculating activity, the four myxobacteria aqueous solution of exopolysaccharide purification were all had flocculation activity. Strains of the 92033 had an effct on 4g/L kaolin suspension and the flocculation rate rich to 92.84% and it showed a good application prospect. Key words:sugar chemical　　exopol