富硒酵母的选育及其培养基组分优化研究

硒是人和动物体的一种必需微量元素。有机硒具有吸收快和毒性小等优点,已成为食品和饲料的首选添加剂。酵母菌具有较强的富集硒并将无机硒转化为有机硒的能力。文章以生产性状已退化的酵母菌为出发菌株,通过亚硝基胍诱变选育,筛选出了一株高产稳定的菌株nw-13,并用正交试验优化了培养基组分,最后对其遗传稳定性进行了验证。结果表明,nw-13的生物量为15.8 g/L,有机硒含量为1754μg/g,均高于同类报道;最适培养基组分为:蔗糖6%,牛肉膏1%,蛋白胨1%,K2HPO40.15%,硒浓度40μg/mL;其遗传稳定性较高。为工业生产提供优良的菌种。

Study on Breeding Se-enriched Yeast and Optimizing Medium Components

Selenium is an essential trace element to human and animal. Organic Se with advantages of fast absorption and low toxicity has been food and feed choice additive. Yeast has strong ability of concentration and conversion inorganic Se to organic Se. In this study one strain nw-13 with high and stable yield has been screened by nitrosoguanidine mutagenesis from the strarting yeast whose production traits have degraded. The orthogonal test was carried out to optimize the medium components, and finally its genetic stability was verified. The results show that the biomass of nw-13 is 15.8 g/L, the content of organic Se is 1754 tg/g and the optimal medium components are sucrose 6 %, beef extract 1%, peptone 1%, K2HPO4 0.15 %, Se 40 μg/mL. The genetic stability is very high. Excellent microbial strain can be provided to industry.