基于麦汁培养基的富硒酵母培养条件优化

Optimal Condition for Selenium-rich Yeast Cultivation in Beerwort Media

以啤酒酵母为材料,对富硒酵母的最适培养条件进行研究。结果显示:以2oBx的麦汁培养酵母菌,其生长得率最高,过高的麦汁质量浓度会产生克拉勃脱效应而影响酵母生长。在2oBx的麦汁培养基中适当添加酵母提取物,可显著提高酵母的生物量,而添加硫酸铵和磷酸二氢钾对酵母生物量的提高不明显;添加葡萄糖在一定程度上也能增加酵母的生物量,但这种增加会被硫酸铵抑制。培养基中的初始硒含量能显著影响酵母的生物量和细胞中硒的积累,在初始质量浓度为10mg/L(最终质量浓度为50mg/L)的Na2SeO3初始质量浓度下培养24h,酵母的生物量可达2.83g/L,细胞中积累的总硒量为266.3mg/kg。

The optimal cultivation condition for yeast growth and selenium accumulation in beerwort media was studied.Results indicated that 2oBx beerwort was a suitable medium for the growth of Saccharomyces cerevisiae and the higher concentration would reduce growth rate by Crabtree effect.The addition of yeast extract in 2oBx beerwort could significantly increase yeast biomass;while the addition of（NH4）2SO4 or KH2PO4 did not.In addition,although glucose addition also could improve yeast biomass,its enhancement effect could be inhibited by simultaneous addition of（NH4）2SO4.Initial selenium concentration in media could remarkably improve yeast biomass and enhance selenium accumulation.At the initial concentration of 10 mg/L Na2SeO3,yeast biomass and accumulated selenium reached up to 2.83 g/L and 266.3 mg/kg,respectively.