Preparation of Selenium Enriched Lactic Acid Bacteria
In this study,Lactobacillus acidophilus,Bifidobacterium animals,Lactobacillus plantarum and Streptococcus thermopiles were used as a test strain for selenium-enriched fermentation experiments,and the selenium enrichment capacity and suitable selenium concentration of the strains were determined.The medium composition of probiotics was optimized by single factor experiment and orthogonal experiment.The fermentation process of selenium enriched probiotics was studied by response surface methodology,and selenium enriched bacterial powder was obtained.The conclusions were as follows:(1)The selenium enriched ability of Lactobacillus acidophilus was most strong in all 4 kinds of Lactobacillus.When the selenium supplemental level was 0-1 000 mg/kg,the number of viable bacteria in the lyophilized powder of Lactobacillus acidophilus could reach hundreds of billions(1 × 1012).The medium formulation of probiotics was optimized that cane sugar was 5％,the total addition amount of peptone and yeast extract was 0.35％,the ratio of peptone and yeast extract was 3:2,and the total supplemental level of K2HPO4 was 0.1％.(2)The optimum selenium enrichment process of Lactobacillus acidophilus was optimized,and the verification experiment was carried out:the selenium content of Lactobacillus acidophilus was 2 902.81 mg/kg,the selenium adding amount was 15.30 mg/kg,and the selenium adding time was 6.64 h.Under these conditions,the final yield of selenium enriched probiotics was 498.46 mg/kg,and the selenium content was 13 039.62 mg/kg.
NETL
NSTL
万方数据
维普
