Isolation, chemical characteristics and immunity activity of an extracellular polysaccharide EPS Ⅰ isolated from Antarctic bacterium Pseudoalteromonas sp. S-15-13

摘要

A new extracelluar polysaccharide (EPS) was isolated and purified from Antarctic bacterium S-15-13, identified as Pseudoalteromonas sp. After being separated and purified by DEAE-Sephadex A-50 ionexchange and Sephadex G-100 gel chromatography, two mains fractions (EPS Ⅰ and EPS Ⅱ) were obtained. EPS Ⅰ was composed of mannose, glucose and galactose with a molecular weight of 23kDa and EPS Ⅱ was composed of mannose only with a molecular weight of 62kDa. The effect of the polysaccharide EPS Ⅰ on the cellular immune response of mice was investigated. Results demonstrated that EPS Ⅰ could markedly facilitate lymphocyte proliferation, and might be a strong immunomodulator.