富硒酿酒酵母的选育及优化培养

Screening and Optimized Culture of Selenium-enriched Saccharomyces cerevisiae

选育高富硒酵母菌株,优化发酵培养条件,以提高酵母生物富集、转化有机硒的能力,为富硒农牧业生产提供一种安全的有机硒源。通过紫外线诱变、抗性筛选试验,获得富硒能力强的酵母菌株,采用单因素及正交试验设计,优化培养基及发酵培养条件。研究结果表明:试验分离筛选得到一株可抗亚硒酸钠5 mg/m L、抗乙硫氨酸10 mg/kg的双抗菌株,经鉴定为酿酒酵母(Saccharomyces cerevisiae)。最佳发酵配方以葡萄糖、蛋白胨、酵母膏为主,添加少量无机盐。确定最优培养条件起始p H 4.0,装液量50m L/500 m L,摇床转速160 r/min,种子液接种量为10%(V/V),30℃培养28 h,在最优发酵培养条件下菌株富硒能力可达26.75 mg/g干菌体。

In order to increase the ability of bio-concentration and organic selenium transform of yeast, andprovide safe organic selenium resource for the production of selenium-rich agriculture and animal husbandry,selenium- enriched yeast was screened and the culture condition was optimized. Selenium- enriched yeaststrain was obtained through UV mutagenesis and resistance screening test, culture medium and fermentcondition were optimized through single factor orthogonal test. The results showed that a strain which couldresist 5 mg/m L sodium selenite and 10 mg/kg ethionine was isolated and identified as Saccharomyces cerevisiae. The optimum ferment formula consisted of glucose, peptone, yeast extract, adding a small amount ofinorganic salt. The optimum culture medium condition was initial p H value of 4, liquid volume of 50 m L/500 m L,shaking speed of 160 r/min, seed inoculation volume of 10%（V/V）, and cultured for 28 h at 30℃, the ability ofselenium-enriched strain was up to 26.75 mg/g dry cell under the optimum condition.