State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, PR China.
Technology Center, Shanxi Xinghuacun Fen Wine Factory Co. Ltd., Fenyang, Shanxi 032205, PR China.
Food Res Int. 2023 Oct;172:113139. doi: 10.1016/j.foodres.2023.113139. Epub 2023 Jun 15.
Light-flavor Baijiu fermentation is a typical spontaneous solid-state fermentation process fueled by a variety of microorganisms. Mechanized processes have been increasingly employed in Baijiu production to replace traditional manual operation processes, however, the microbiological and physicochemical dynamics in mechanized processes remain largely unknown. Here, we investigated the microbial community succession and flavor compound formation during a whole mechanized fermentation process of light-flavor Baijiu using the conventional dilution plating method, PacBio single-molecule real-time (SMRT) sequencing and headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry. The results showed that largely different fungal and bacterial communities were involved in the soaking and fermentation processes. A clear succession from Pantoea agglomerans to Bacillus (B.) smithii and B. coagulans in dominant bacterial species and from Cladosporium exasperatum to Saccharomyces cerevisiae and Lichtheimia ramosa in dominant fungal species occurred in the soaking processes. In the fermentation process, the most dominant bacterial species was shifted from Pantoea agglomerans to Lactobacillus (La.) acetotolerans and the most dominant fungal species were shifted from Lichtheimia ramose and Rhizopus arrhizus to Saccharomyces cerevisiae. The bacterial and fungal species positively associated with acidity and the formation of ethanol and different flavor compounds were specified. The microbial species exhibited strong co-occurrence or co-exclusion relationships were also identified. The results are helpful for the improvement of mechanized fermentation process of light-flavor Baijiu production.
清香型白酒发酵是一种典型的以多种微生物为动力的固态自发发酵过程。机械化工艺已越来越多地应用于白酒生产，以取代传统的人工操作过程，但机械化工艺中的微生物学和物理化学动态仍知之甚少。在这里，我们使用常规的稀释平板法、PacBio 单分子实时（SMRT）测序和顶空固相微萃取结合气相色谱-质谱法，研究了清香型白酒整个机械化发酵过程中的微生物群落演替和风味化合物形成。结果表明，浸泡和发酵过程涉及到差异很大的真菌和细菌群落。在浸泡过程中，从成团泛菌（Pantoea agglomerans）到解淀粉芽孢杆菌（Bacillus (B.) smithii）和凝结芽孢杆菌（B. coagulans）的优势细菌种属的明显演替，以及从粗糙青霉（Cladosporium exasperatum）到酿酒酵母（Saccharomyces cerevisiae）和光柄菇（Lichtheimia ramosa）的优势真菌种属的明显演替。在发酵过程中，优势细菌种属从成团泛菌（Pantoea agglomerans）转变为耐乙酸乳酸杆菌（Lactobacillus (La.) acetotolerans），优势真菌种属从光柄菇（Lichtheimia ramose）和根霉（Rhizopus arrhizus）转变为酿酒酵母（Saccharomyces cerevisiae）。确定了与酸度、乙醇和不同风味化合物形成呈正相关的细菌和真菌种属。还鉴定了表现出强烈共同发生或排斥关系的微生物种属。这些结果有助于清香型白酒机械化发酵过程的改进。
