以根瘤菌发酵液为原料,提取纯化发酵液中胞外多糖(extracellular polysaccharides,EPS),并对其多糖组分进行分析。采用木瓜蛋白酶与sevage法结合脱蛋白,并利用柱层析法对胞外多糖进行单组分离和纯化,分别得到EPS 1-1、EPS 2-1、EPS 3-1、EPS 4-1和EPS 5-1等5种相对较纯的单一组分。分别采用不同色谱法对上述各单一组分的纯度、结构、相对分子量及单糖组成进行分析和测定,表明各个组分均具有多糖特征峰,且均是以β-型糖苷键连接的吡喃糖,其中EPS 1-1和EPS 3-1是β构型的半乳吡喃糖;5种多糖组分均主要由具有不同摩尔比的半乳糖、葡萄糖和甘露糖组成,除了EPS 4-1之外,在其他组分中还检测到了不同含量的岩藻糖、鼠李糖和阿拉伯糖等。
The extracellular polysaccharides (EPS) were extracted from the fermentation broth of Rhizobium,and their components were analyzed. Proteins were removed from EPS by papain combined with the Sevage method,followed by separating and purifying by column chromatography. Five relatively pure single components: EPS 1-1,EPS 2-1,EPS 3-1,EPS 4-1,and EPS 5-1 were purified. It was found that each component had a characteristic peak of polysaccharides,and all of them were pyranose linked by β-type glycosidic bonds. Moreover,EPS 1-1 and EPS 3-1 were galactose pyranose in a β-configuration. Furthermore,these five polysaccharides were mainly composed of galactose,glucose,and mannose with different molar ratios. Additionally,EPS 1-1,EPS 2-1,EPS 3-1,and EPS 5-1 also had different levels of fucose,rhamnose,and arabinose. Overall,this study lays a good foundation for further study on structures and activities of EPS.
Food and Fermentation Industries
separation and purification