高产酯酿酒酵母与乳酸菌共发酵过程中的相互作用研究

Interactions of High Ester Producing Saccharomyces cerevisiae and Lactic Acid Bacteria during Co-fermentation

酵母菌和乳酸菌是各种酿酒生产中两类非常重要的发酵微生物,其相互作用对酒的产量和质量有很大影响。本试验主要研究了高产酯酿酒酵母MY-15和酿酒过程中三种常见乳酸菌(Lactobacillus casei lca、Pediococcus pentosaceus L1和Bacillus coagulans NJ)在生长和代谢方面相互间的影响。结果表明,乳酸菌对高产酯酿酒酵母MY-15的生长和产乙酸乙酯有明显的抑制作用,对产酒的影响不大;但乳酸菌的代谢产物乳酸对酿酒酵母的生长和代谢有明显的抑制作用。高产酯酿酒酵母MY-15对干酪乳杆菌lca的生长抑制作用明显,但少量的酵母菌对戊糖片球菌L1和凝结芽孢杆菌NJ的生长有促进作用;随着酵母菌接种量的增加,乳酸菌代谢乳酸呈先增后减的趋势;酵母菌代谢产物乙醇对乳酸菌的生长和代谢,在乙醇含量少于7.5%(V/V)时,抑制作用不明显;当酒精含量达17.5%(V/V)时,乳酸菌的生长被完全抑制。

Yeast and lactic acid bacteria are two kinds of important fermentative microorganisms in liquor production and their interactions that have significant impact on the production and quality of liquor. The effects of the interactions of Saccharomyces cerevisiae MY-15, producing high levels of ester, and three common lactic acid bacteria（Lactobacillus casei lca, Pediococcus pentosaceus L1, and Bacillus coagulans NJ） in liquor production on the growth and metabolism were analyzed in this study. The results demonstrated that lactic acid bacteria significantly inhibited the growth and ethyl acetate-production of S. cerevisiae MY-15, and had marginal impact on the liquor production. However, lactic acid, the metabolite produced by lactic acid bacteria, had a remarkable inhibitory effect on the growth and metabolism of S. cerevisiae. S. cerevisiae, producing high-yield ester could significantly inhibit the growth of L. casei lca; however, in small amounts it stimulated the growth of P. pentosaceus L1 and B. coagulans NJ. With increasing amounts of inoculated S. cerevisiae cells, the amount of lactic acid produced as a result of the metabolism of lactic acid bacteria showed a downward trend after an initial increase. The inhibitory effect of ethanol on the growth and metabolism of lactic acid bacteria was not significant when the content of ethanol was less than 7.5%（V/V）. However, when the content of ethanol was increased to 17.5%（V/V）, the growth of lactic acid bacteria was completely suppressed.