College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, PR China.
Nutrition & Health Research Institute, COFCO Corporation, Beijing 102209, PR China; Beijing Key Laboratory of Nutrition, Health and Food Safety, Beijing 102209, PR China; Jiugui Liquor Co., LTD, Hunan 416000, PR China.
Food Res Int. 2022 Apr;154:111008. doi: 10.1016/j.foodres.2022.111008. Epub 2022 Feb 14.
The seasonal spontaneous fermentation depends on the assembly of specific microbiota. However, a knowledge gap remains regarding the seasonal dynamics of microbial community and functionality. This study aimed to investigate the differences in microbial community dynamics during the saccharification process of Fuyu-flavor Baijiu in winter versus summer by employing high-throughput sequencing. It also explored the driving effects of environmental variables on the microbial succession. The environmental temperature of saccharification in summer (29 ± 1 °C) was strikingly different in winter (14 ± 1 °C), leading to a longer incubation time in winter fermentation. The dominant bacterial genera displayed in the early stage of the summer saccharification process were Staphylococcus, unclassified Enterobacteriaceae, and Weissella, whereas the dominant genus was Weissella during the middle stage and Lactobacillus during the late stage of saccharification. In contrast, unclassified Enterobacteriaceae and Weissella were dominant genera throughout the winter saccharification process. In the fungal community, Rhizopus was the dominant genus in summer and winter saccharification. Principal coordinate analysis revealed that the changes in the environmental temperature in winter versus summer had distinct impacts on the microbial community structure. Also, temperature was the key factor driving the succession of bacterial community, whereas pH was the main factor driving the succession of dominant fungi. Predictive gene functionality of bacterial and fungal communities was computed using the Phylogenetic Investigation of Communities by Reconstruction of Unobserved States 2 against Kyoto Encyclopedia of Genes and Genomes (KEGG) database and MetaCyc database, respectively. Correlation networks were constructed to better understand the relationships between dominant microbial genera and physicochemical factors during the saccharification process. These results provided new insights into the Baijiu fermentation technology and allowed a theoretical basis for exploring effective management strategies regarding traditional fermentation in response to complex seasonal factors.
季节性自然发酵取决于特定微生物群落的组合。然而，微生物群落和功能的季节性动态仍然存在知识空白。本研究旨在通过高通量测序研究冬夏两季福裕风味白酒糖化过程中微生物群落动态的差异，并探讨环境变量对微生物演替的驱动作用。夏季糖化（29±1°C）的环境温度与冬季（14±1°C）有明显差异，导致冬季发酵的发酵时间更长。夏季糖化早期的优势细菌属为葡萄球菌、未分类肠杆菌科和魏斯氏菌，而中期的优势属为魏斯氏菌，后期的优势属为乳杆菌。相比之下，未分类肠杆菌科和魏斯氏菌是冬季糖化过程中的优势属。在真菌群落中，根霉是夏季和冬季糖化的优势属。主坐标分析显示，冬夏环境温度的变化对微生物群落结构有明显的影响。此外，温度是驱动细菌群落演替的关键因素，而 pH 是驱动优势真菌演替的主要因素。利用未观察状态重建对群落系统发育的推测性基因功能分析（PICRUSt2）分别对细菌和真菌群落进行了基于京都基因与基因组百科全书（KEGG）数据库和元代谢途径数据库的预测基因功能分析。构建了相关网络，以更好地了解糖化过程中优势微生物属与理化因素之间的关系。这些结果为白酒发酵技术提供了新的见解，并为探索应对复杂季节性因素的传统发酵有效管理策略提供了理论依据。
