Abstract: 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.
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