ABSTRACT
Objective To investigate the screening of the Antarctic bacteria producing the extracellular polysaccharides(EPS),identification of the bacterium S-15-13 producing higher EPS by 16SrDNA,and the effects of the extracellular polysaccharide(EPSⅠ)on the cellular immune response in mice. Methods The Antarctic bacteria producing extracellular polysaccharide were screened by microscope observation and staining method;the phylogenetic position of S-15-13 was determined on the basis of amplification,comparison and analysis of almost complete 16S rDNA sequence and the effect of its extracellular polysaccharide on proliferation of murine lymphocytes was determined by method of Heek.Results and Conclusion Out of 57 strains of the Antarctic bacteria,27 strains were found to produce EPS according to the staining technique.The result of 16SrDNA demonstrated that strain S-15-13 belong to the genus Pseudoalteromonas sp.The purified fractionⅠ(EPSⅠ) produced by the bacterial strain S-15-13 obviously promoted proliferation of lymphocytes when used alone or with(Con A.)