Preparation And Study On Streptococcus Thermophilus S230 Selenium Exoplysaccharide And Biological Selenium

Selenium was understood and acquainted by people from the last century. Selenium biochemistry became another central topic of contemporary research disciplines, not only in theory, but the application was also made great progress. Currently, there are a variety of selenium health care products and Pharmaceuticals on the market, the selenium polysaccharide has shown better health benefits and clinical value especially. However, the function and production of natural selenium polysaccharide could not meet people’s demand. Streptococcus thermophilus sp. S230 exopolysaccharide (STSEPS)was modified seleninic in order to obtain a new efficient and low toxic anti-cancer agents. It was found that the polysaccharide active and selenium efficacy of modified polysaccharides had made a major change.1. Our laboratory has screened resistant strains of selenium. Streptococcus thermophilus synthesized selenide extracellular polysaccharide by thermophilic sodium selenite on molecular modification. We finally obtained high efficiency and low toxicity of new selenium extracellular polysaccharide preparations and biological selenium preparations.2. IR results showed that the selenium-carbon bond absorption peak in spectrum and reducing of -OH caused by esterification were described STSEPS successfully combined with selenium.3. Important medium components affecting STSEPS production were identified by response surface analysis based on a Box-Behnken design. Selenium content etc. had significant effects on STSEPS production (P<0.05). Use Mintab software to analyze test results. There was a significant interaction effect between selenium content and inoculum size, inoculum size and incubation time. The optimized condition of incubation was inoculum size of 4%, incubation time of 10.06 h, selenium content of 30 mg/L, resulting in a STSEPS yield of 103.2 μg/g.4. Saccharomyces cerevisiae, Streptococcus thermophilus S230 were inoculated 28 ℃ or 37 ℃ on different concentrations of selenium liquid medium. After the measurement by FAAS hydride, the highest selenium concentrations of strains were elected. We inoculated the mixed strains under appropriate conditions, the selenium content of complex strains were measured. Experimental results showed that two strains of selenium-enriched ability steeled were, Saccharomyces cerevisiae D245 11.8 μg/mL, Streptococcus thermophilus S23012.0 μg/mL. The composite strain with the most highest selenium-enriched capacity is Saccharomyces cerevisiae-Streptococcus thermophilus S230, the combined selenium concentration is 15.9 μg/mLIn a word, the technology of preparation Se-STSEPS was established. A new polysaccharide product and high selenium content hybrid strains preparations were gained in the paper. The study lays a certain foundation for the production and application of Se-STSEPS and biological selenium.