Wu Qun, Kong Yu, Xu Yan
State Key Laboratory of Food Science and Technology, Key Laboratory of Industrial Biotechnology, Ministry of Education, Synergetic Innovation Center of Food Safety and Nutrition, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China.
State Key Laboratory of Food Science and Technology, Key Laboratory of Industrial Biotechnology, Ministry of Education, Synergetic Innovation Center of Food Safety and Nutrition, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China
Appl Environ Microbiol. 2015 Oct 16;82(2):422-30. doi: 10.1128/AEM.02518-15. Print 2016 Jan 15.
The flavor profile of Chinese liquor is the result of the metabolic activity of its microbial community. Given the importance of the microbial interaction, a novel way to control the liquor's flavor is by regulating the composition of the community. In this study, we efficiently improved the liquor's flavor by perturbing the intrinsic microbial metabolism with extrinsic microbes. We first constructed a basic microbial group (intrinsic) containing Saccharomyces cerevisiae, Wickerhamomyces anomalus, and Issatchenkia orientalis and added special flavor producers (extrinsic), Saccharomyces uvarum and Saccharomyces servazzii, to this intrinsic group. Upon the addition of the extrinsic microbes, the maximum specific growth rates of S. cerevisiae and I. orientalis increased from 6.19 to 43.28/day and from 1.15 to 14.32/day, respectively, but that of W. anomalus changed from 1.00 to 0.96/day. In addition, most volatile compounds known to be produced by the extrinsic strains were not produced. However, more esters, alcohols, and acids were produced by S. cerevisiae and I. orientalis. Six compounds were significantly different by random forest analysis after perturbation. Among them, increases in ethyl hexanoate, isobutanol, and 3-methylbutyric acid were correlated with S. cerevisiae and I. orientalis, and a decrease in geranyl acetone was correlated with W. anomalus. Variations in ethyl acetate and 2-phenylethanol might be due to the varied activity of W. anomalus and S. cerevisiae. This work showed the effect of the interaction between the intrinsic and extrinsic microbes on liquor flavor, which would be beneficial for improving the quality of Chinese liquor.
中国白酒的风味特征是其微生物群落代谢活动的结果。鉴于微生物相互作用的重要性，一种控制白酒风味的新方法是调节群落组成。在本研究中，我们通过用外源微生物干扰内在微生物代谢，有效地改善了白酒的风味。我们首先构建了一个包含酿酒酵母、异常威克汉姆酵母和东方伊萨酵母的基本微生物组（内在组），并向这个内在组中添加了特殊风味产生菌（外源）葡萄汁有孢汉逊酵母和塞尔瓦齐酵母。添加外源微生物后，酿酒酵母和东方伊萨酵母的最大比生长速率分别从6.19提高到43.28/天和从1.15提高到14.32/天，但异常威克汉姆酵母的最大比生长速率从1.00变为0.96/天。此外，已知由外源菌株产生的大多数挥发性化合物并未产生。然而，酿酒酵母和东方伊萨酵母产生了更多的酯类、醇类和酸类。扰动后通过随机森林分析有六种化合物存在显著差异。其中，己酸乙酯、异丁醇和3-甲基丁酸的增加与酿酒酵母和东方伊萨酵母相关，香叶基丙酮的减少与异常威克汉姆酵母相关。乙酸乙酯和2-苯乙醇的变化可能归因于异常威克汉姆酵母和酿酒酵母活性的变化。这项工作展示了内在和外源微生物之间的相互作用对白酒风味的影响，这将有利于提高中国白酒的品质。
