Key Laboratory of Industrial Biotechnology of Ministry of Education, State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China.
Key Laboratory of Industrial Biotechnology of Ministry of Education, State Key Laboratory of Food Science and Technology, Synergetic Innovation Center of Food Safety and Nutrition, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China; Key Laboratory of Wuliangye-Flavor Liquor Solid-State Fermentation, China National Light Industry, Yibin, Sichuan, China.
Int J Food Microbiol. 2019 Dec 2;311:108350. doi: 10.1016/j.ijfoodmicro.2019.108350. Epub 2019 Sep 6.
Solid-state fermentation is a dynamic process involved with complex microbiome. Microbial structure and succession significantly affect the yield and quality of fermentation productions. Although the importance of microbial structure was extensively studied, the significance of microbial succession rate remains unclear in solid-state fermentation. To address this gap, we designed an in situ experiment in a typical distillery to characterize the effects of microbial succession rate. In this study, we found the process of strong-aroma Baijiu making could be divided into two stages according to fermentation parameters (starch, moisture, acidity, reducing sugar, alcohol, temperature). The early stage showed significantly (p < 0.05) higher microbial diversity than that of the later stage according to Shannon index. Compared with single cereal fermentation, mixed cereals fermentation showed slower microbial succession rate of stage shift. We found that Lactobacillus could reflect microbial succession rate of stage shift in strong-aroma Baijiu fermentation. Meanwhile, we found fermentation parameters could affect microbial succession rate of stage shift. Microbial diversity was significantly (p < 0.05) correlated with fermentation parameters. Moreover, molecular ecological network analysis (MENA) showed that succession rate of microbial community could affect microbial interactions. In addition, fermentation of mix cereals (sorghum, wheat, corn, rice and glutinous rice) increased the enrichment of Clostridiales from pit mud according to results of source tracking. Collectively, succession rate of microbial community could be an important trait to explain differences of microbial diversity and flavor profile from the perspective of microbial decline and enrichment. Our study highlighted the importance of microbial succession rate during strong-aroma Baijiu making process and provided a dynamic perspective to observe solid-state fermentation.
固态发酵是一个涉及复杂微生物组的动态过程。微生物结构和演替显著影响发酵产物的产量和质量。虽然微生物结构的重要性已经得到了广泛的研究，但在固态发酵中，微生物演替率的意义仍不清楚。为了解决这一差距，我们设计了一个典型酿酒厂的原位实验来描述微生物演替率的影响。在这项研究中，我们发现根据发酵参数（淀粉、水分、酸度、还原糖、酒精、温度），强香白酒的酿造过程可以分为两个阶段。根据 Shannon 指数，早期的微生物多样性明显（p<0.05）高于后期。与单一谷物发酵相比，混合谷物发酵的阶段转换的微生物演替率较慢。我们发现乳酸菌可以反映强香白酒发酵中阶段转换的微生物演替率。同时，我们发现发酵参数可以影响阶段转换的微生物演替率。微生物多样性与发酵参数显著相关（p<0.05）。此外，分子生态网络分析（MENA）表明，微生物群落的演替率可以影响微生物的相互作用。此外，混合谷物（高粱、小麦、玉米、大米和糯米）的发酵根据源追踪结果增加了从窖泥中富集梭菌。总的来说，从微生物衰减和富集的角度来看，微生物群落的演替率可以作为解释微生物多样性和风味特征差异的一个重要特征。我们的研究强调了在强香白酒酿造过程中微生物演替率的重要性，并提供了一个观察固态发酵的动态视角。
