耐高渗酵母选育及其在葡萄酒中的应用研究

高醇、高糖、高硫等条件会影响酵母菌的生物活性。为筛选出耐高酒精度、高糖度、高SO2浓度的葡萄酒酿造优良菌株，该实验采集葡萄酒糟、黄酒糟、酒醅，经过富集筛选分离纯化得到8株酵母菌，经高酒精度、高糖度、高SO2耐受试验后初步筛选出2株菌株，一株耐高糖，在含糖量60%条件下21.5 h仍可启动发酵；一株耐高酒精度，在酒精度20%vol条件下21.3 h仍可启动发酵；2株菌株均可在300 mg/L SO2条件下在6.7 h启动发酵。经生理生化试验初步鉴定两株菌分别为酿酒酵母（Saccharomyces cerevisiae）和膜醭毕赤氏酵母（Pichia membranefaciens）。在浓缩葡萄汁初始糖含量28%条件下接种酿酒酵母，高泡期补料至含糖量34%接种膜醭毕赤氏酵母，20 ℃发酵15 d，得到的葡萄酒酒精度为18.1%vol。

Breeding of hyperosmotic yeasts and their application in wine

High alcohol, high sugar, high sulfur and other conditions could affect the biological activity of yeast. In order to screen the excellent strains of wine brewing that tolerate high alcohol content, high sugar content and high SO2 concentration, 8 strains were screened initially from wine lees, Huangjiu (Chinese rice wine) lees and fermented grains after enrichment and screening. After high alcohol content, high sugar content, and high SO2 tolerance experiments, 2 strains were screened, one strain was tolerant to high sugar, and the fermentation could be started at 21.5 h with sugar content 60%, the other one was tolerant to high alcohol, and the fermentation could be started at 21.3 h after adding 20%vol alcohol. Under the condition of 300 mg/L SO2, both strains could start fermentation at 6.7 h. The two strains were preliminarily identified as Saccharomyces cerevisiae and Pichia membranefaciens by physiological and biochemical tests. S. cerevisiae was inoculated under the condition of initial sugar content 28% of concentrated grape juice, and then P. membranifaciens was inoculated to sugar content 34% at high bubble stage. The wine was fermented at 20 ℃ for 15 d, and the alcohol content of the wine was 18.1%vol.