基于液滴微流控技术选育超高浓酿造啤酒酵母菌株

Breeding of very high gravity brewing strains based ondroplet microfluidic technology

超高浓酿造可以降低成本、节约能耗,但高浓酿造的酵母需要具备良好的抗逆性能。为了提高筛选效率,获得性能稳定的超高浓酿造菌株,该研究建立了基于液滴微流控技术的啤酒酵母高通量筛选方法,并以啤酒酵母Saccharomyces pastorianus 02为出发菌株,经常压室温等离子体诱变,液滴微流控酒精初筛,α-葡萄糖苷酶和乙醇脱氢酶Ⅱ活力复筛及发酵实验,获得了遗传和发酵稳定性良好的超高浓啤酒酿造菌株9-50。与出发菌株相比,其在中试规模下增殖旺盛,发酵周期缩短42 h,并可适应9%的乙醇体积分数,发酵度达66%以上,双乙酰含量0.06 mg/L,醇酯香气较协调,具有较好的工业应用前景。

While the ultra-high gravity brewing technology reduces costs and energy consumption,good stress-resistant performance is a must for yeast needed in high gravity brewing.To get ultra-high gravity brewing strain of reliable capability through a more efficient screening process,this study hereby establishes a high-throughput screening method for brewer’s yeast based on droplet microfluidic technology.The Saccharomyces pastorianus 02 was used as the starting yeast strain,with atmospheric room temperature plasma(ARTP)mutagenesis,droplet microfluidic initial screening,α-glycosidase(α-GC)and alcohol dehydrogenaseⅡ(ADHⅡ)activity re-screening,and fermentation experiment,results in a very high gravity brewing strain 9-50 of good genetic and fermentation stability.Compared with the starting strain,the resulting strain proliferated vigorously with a fermentation period shortened by 42 h in the pilot scale,and adapted to an environment of 9%vol high ethanol concentration while delivering a fermentation degree of more than 66%,and diacetyl content of 0.06 mg/L with well-balanced aroma of alcohol ester,brining it good application prospects in the brewing industry.