低产乙醛啤酒酵母的定向驯化筛选

Screening of brewer's yeast with low acetaldehyde by directional domestication

为降低啤酒中乙醛含量,采用紫外线对1株啤酒工业生产菌株MI4进行诱变,经双硫仑平板初筛、乙醛培养基驯化复筛,获得了1株低产乙醛的啤酒酵母D-A-14。与出发菌株MI4相比,采用该突变株酿制的啤酒中乙醛含量为2.86 mg/L,降低了76%;且高级醇总量降低而酯含量升高,风味更加协调。这表明筛选得到的低乙醛突变株适于啤酒工业生产。

Aiming at reduce the acetaldehyde concentration in beer, an industrial brewing yeast strain M4^1 was used as original strain and mutagenized with ultraviolet radiation. After primary screening with disulfiram and domestication with media containing acetaldehyde, a mutant strain D-A-14 was obtained with considerably low yield of acetaldehyde. The concentration of acetaldehyde in the beer brewed with the mutant strain was 2.86 mg/L, which was 76% lower than that of M4^1. In the meantime, the beer brewed with the mutant strain contained less higher alcohols and more esters and showed more harmonious flavor. These results demonstrated that the low -acetaldehyde mutant strain D-A-14 would be suitable for beer industry.