Studies On Extraction, Purification And Anti-bacteria Bioactivity Of Polysaccharides From S. Naozhouense Sp. Nov .

S. naozhouense sp. nov. was studied in our research, we optimized the extraction of polysaccharides, explore the process of separation and purification, illustrate the composition and structure and give a primary discuss about their anti-bacterium activity.The main chemical constituents of S. naozhouense sp. nov. were analyzed. The results showed that carbohydrates, crude protein and ash were its main constituent, which was 85 % of the dry weight. The insoluble dietary fiber reached 10.88 %. The content of protein reached 13.95 %, and EAA content was 41% of the total AA, EAA/NEAA reached 0.69. Crude fat content was 2.4 %. The content of minerals were rich, especially Fe, Zn.Optimum condition of extraction of S. naozhouense sp. nov. polysaccharide is optimized by response surface test. On the basis of single-factor test, the mathematical regression model is established about the dependent variable (extraction yield of S. naozhouense sp. nov. polysaccharide ) and independent variables (extraction temperature, extraction time and ratio of material to water) using Box-Benhnken center composite design and response surface methodology. The optimum extraction conditions as follows: extraction temperature 90.7℃, extraction time 5.1h, material to water ratio 1︰21.Under these conditions, the yield of S. naozhouense sp. nov. polysaccaride is 6.39%.SNP(S. naozhouense sp. nov. polysaccharides) after through DEAE-52 cellulose ion-exchange column chromatography, obtained 5 peaks, collect the two most important peaks, named SNP2 and SNP3; SNP2 and SNP3 then purified by Sephadex G-100 dextran gel column chromatography, obtained two more pure polysaccharide named SNP2-2 and SNP3-2 .Through cellulose acetate membrane electrophoresis identified that SNP2-2 and SNP3-2 were two relatively pure polysaccharide; through the infrared spectrum analysis found that SNP2-2 and SNP3-2 have the polysaccharide characteristic absorption peaks; through gas chromatography analysis, SNP2-2 is mainly comprised of xylose, mannose, glucose and galactose in the molar ratio of 0.25:1.37:1:0.17. SNP3-2 is mainly comprised of arabinose, xylose, mannose,glucose and galactose in the molar ratio of 0.44:0.28:1.10:1:0.23; through gel permeation chromatography analysis, the molecular weight of SNP2-2 is 8.30×104Da, the molecular weight of SNP3-2 is 1.22×105DaThe anti-bacterial activity of SNP2-2 and SNP3-2 were evaluated by Microplate. We found that when the concentration reached 1.25mg/mL, the two polysaccharide had good antibacterial activity; through preliminary scanning electron microscope inferred that the anti-bacterial mechanism of SNP2-2 and SNP3-2 may inhibit the normal proliferation of the bacteria.There is no report about polysaccharides of S. naozhouense sp. nov. inside and outside, our research has given a first report about the purification methods, chemical composition and structure and primary bio-activity of it. And we hope it can provide the theory basis for the development and use of S. naozhouense sp. nov.