贺兰山东麓优良本土酿酒酵母筛选及发酵特性分析

Screening and fermentation of excellent indigenous Saccharomyces cerevisiae strains from eastern foothills of Helan Mountains

摘要:

【背景】商业酵母的使用造成葡萄酒同质化问题严重，发掘优良本土酿酒酵母具有十分重要的意义。【目的】从168株宁夏本土酿酒酵母菌株中筛选出性能优良、具有出色葡萄酒发酵能力的菌株。【方法】基于杜氏管发酵试验和乙醇、高糖等耐受性试验分析产H₂S能力及生长曲线测定的方法，筛选出发酵力好、耐受性强、低产H₂S的本土酿酒酵母进行赤霞珠葡萄酒发酵试验，测定葡萄酒样基础理化指标、酚类物质和挥发性成分，探究筛选出的酿酒酵母发酵特性。【结果】初步筛选出发酵快速，能适应13%乙醇、350 g/L葡萄糖、250 mg/L SO₂、pH 1.0的生存环境且低产H₂S的4株本土酿酒酵母YC-E8、QTX-D17、QTX-D7、YQY-E18。菌株YC-E8产甘油能力强，所发酵酒样香气与商业酵母XR、F33最为接近，适用于赤霞珠葡萄酒的发酵。菌株QTX-D17发酵酒样中酒精、单宁、总酚和花色苷含量最高，表现出本土酿酒酵母优良的发酵特性。菌株QTX-D7所发酵酒样香气中乙酸乙酯、辛酸乙酯、1-壬醇等物质含量较高，赋予了葡萄酒香蕉味、苹果味、菠萝味、椰子味等愉悦花果香。【结论】最终筛选出3株优良本土酿酒酵母QTX-D17、YC-E8和QTX-D7，其酿酒特性风格不一，有潜力酿造产区特色葡萄酒，为宁夏贺兰山东麓产区的酿酒微生物资源开发提供参考价值。

Abstract:

[Background] The application of commercial yeasts has caused a serious problem of wine homogenization. It is significant to explore excellent indigenous strains of Saccharomyces cerevisiae. [Objective] To screen out the S. cerevisiae strains with excellent wine fermentation performance from 168 yeast strains isolated from the eastern foothills of Helan Mountains. [Methods] Duchenne tube fermentation, tolerance tests, and H₂S production experiments and growth curve establishment were employed to screen out the indigenous S. cerevisiae strains with excellent fermentation ability, strong stress tolerance, and low H₂S production for Cabernet Sauvignon wine production. We determined the basic physicochemical indexes and the content of phenols and volatile compounds in wine samples to explore the fermentation characteristics of the candidate yeast strains. [Results] Four indigenous S. cerevisiae strains, YC-E8, QTX-D17, QTX-D7, and YQY-E18 with rapid fermentation, low H₂S production, and tolerance to 13% ethanol, 350 g/L glucose, 250 mg/L SO₂, and pH 1.0 were preliminarily screened out. The strain YC-E8 showed high glycerol production and produced the wine sample with similar aroma to those prepared with commercial yeasts XR and F33, being suitable for brewing Cabernet Sauvignon wine. The wine sample fermented with strain QTX-D17 had the highest content of alcohol, tannin, total phenols, and anthocyanins, which indicated the excellent fermentation characteristics of QTX-D17. In the wine sample fermented with strain QTX-D7, the content of ethyl acetate, ethyl caprylate, and 1-nonanol endowing the wine with pleasant floral and fruity aromas such as banana, apple, pineapple, and coconut aromas were higher. [Conclusion] Finally, three indigenous S. cerevisiae strains QTX-D17, YC-E8, and QTX-D7 were screened out. The three strains exhibit diverse fermentation characteristics in the winemaking process and provide novel yeast strains for exploiting the microorganism resources in the wine-producing region at the eastern foothills of Helan Mountains in Ningxia.