富硒酿酒酵母的选育及优化培养

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/mL、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pH 4.0，装液量50 mL/500 mL，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。

Screening and Optimized Culture of Selenium-enriched Saccharomyces cerevisiae

In order to increase the ability of bio-concentration and organic selenium transform of yeast, and provide 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 yeast strain was obtained through UV mutagenesis and resistance screening test, culture medium and ferment condition were optimized through single factor orthogonal test. The results showed that a strain which could resist 5 mg/mL 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 of inorganic salt. The optimum culture medium condition was initial pH value of 4, liquid volume of 50 mL/500 mL, shaking speed of 160 r/min, seed inoculation volume of 10% (V/V), and cultured for 28 h at 30℃, the ability of selenium-enriched strain was up to 26.75 mg/g dry cell under the optimum condition.