富硒益生菌的筛选及其富硒条件的优化

为了获得能耐受较高亚硒酸钠质量浓度和具有富硒能力的益生菌菌株，对7株酵母菌和12株乳酸菌进行了筛选。结果表明，所有菌株均能在亚硒酸钠质量浓度为20~80 μg/mL的平板上生长，乳酸菌YQRS菌株和酵母菌FJYJM3菌株具有较高的耐受性和富硒能力。对它们进行发酵条件的优化，表明YQRS菌株在亚硒酸钠添加量为15 μg/mL、添加硒的时间为对数期前期时，富硒效果最好，菌体生物量为2.66 g/L，总硒含量能达到2 300.26 μg/L。而FJYJM3菌株在亚硒酸钠添加量为20 μg/mL，添加硒的时间为对数期前期时，富硒效果最显著，生物量能达到4.86 g/L，总硒含量能达到5 790.99 μg/L。
In order to obtain the Se-enriched probiotics strains which could tolerate high NaSeO3 concentration，7 strains of yeast and 12 strains of Lactobacillus were screened in this study. Results showed that all strains could grow on the plate with NaSeO3 concentrations of 20~80 μg/mL. Among them，strains of yeast FJYJM3 and Lactobacillus YQRS had higher tolerance and se-enriched ability. The optimization fermentation conditions showed that strain of YQRS had the highest se-enrichment when the addition concentration of NaSeO3 was 15 μg/mL and it was added at beginning of logarithmic phase. The biomass was 2.66 g/L and the total selenium content could reach to 2 300.26 μg/L. However，strain of FJYJM3 had the highest se-enrichment when the addition concentration of NaSeO3 was 20 μg/mL at beginning of logarithmic phase. Its biomass was up to 4.86 g/L and the total selenium content could reach to 5 790.99 μg/L