以啤酒酿造Lager酵母TS-01为出发菌株,依次利用含乙硫氨酸、羟基正缬氨酸的平板进行定向育种,利用硝酸铅平板分离出高产SO2、低产H2S的菌株,然后通过EBC管、100 L中试发酵试验,以发酵液的SO2、H2S、双乙酰、乙醛、高级醇的含量和发酵度为筛选指标,得到1株发酵性能优良的菌株TK-10。以出发菌株TS-01为对照进行600 t大生产对比验证,表明新菌株TK-10的SO2产量明显升高,成品酒抗氧化性能得到改善,且口感良好,保持原有风味不变。

Brewer's lager yeast strain TS-01(Saccharomyces pastorianus) was selected as parent strain for directed breeding with resistance induction on medium containing ethionine and hydroxynorvaline successively.Mutant stains with high SO2 and low H2S production were obtained by screening with medium containing lead nitrate.The mutants were fermented in EBC tube and 100L tank for pilot fermentation respectively using the content of SO2,H2S,diacetyl,aldehyde,higher alcohols and the fermentation degree as the selecting indexes.As a result,TK-10 was obtained as strain with optimal fermentation performance.Industrial fermentation was conducted in 600T tank with the parent strain TS-01 as a control.The results showed that TK-10 was obviously increased in the production of SO2 with improved antioxygenic property of beer product.In addition,the beer flavor was maintained with good sensory evaluation.