Analysis of bacterial diversity and functional differences of Jiang-flavored Daqu produced in different seasons

Abstract

High-temperature Daqu is an important saccharifying fermenting starter for brewing Jiang-flavored Baijiu. This paper analyzed the diversity characteristics of bacterial communities of Jiang-flavored Daqu (JFDQ) with seasonal changes through Illumina HiSeq sequencing and multivariate statistical methods. Results showed that 21 phyla, 529 genera, and 47 core bacterial genera were identified from the 48 composite samples. Among them, eight functional genera were only found in the summer-produced Daqu (Propionigenium, etc.). Pantoea, Bacillus, Lentibacillus, and Oceanobacillus, respectively, served as the representative functional bacterial genera of the four seasons. Functional prediction analysis showed that Amino acid metabolism Carbohydrate metabolism, Lipid metabolism, Metabolism of cofactors and vitamins, and Nucleotide metabolism (relative abundance > 1%) were the most critical microbial functions in JFDQ, and these key enzymes involved in acetoin biosynthesis, and acetyl-CoA biosynthesis were more abundant in the summer than in the winter. The functional microorganisms community in this paper would provide valuable suggestions about the seasonal production of JFDQ, guiding the Baijiu brewing processes.

Seasonal dynamics of the microbial community in a strong‐flavor baijiu fermentation

“…These outcomes are partially inconsistent with previous studies. 14,21 Lactobacillus showed significant seasonal differences in abundance among core bacterial genera, while for fungi, two core genera, including Thermoascus and Kazachstania, showed notable seasonal discrepancies. Lactobacillus emerged as the dominant bacterial genus in all samples, which is consistent with prior investigations.…”

“…Previous studies have shown that changes in temperature and precipitation, which are associated with seasonal variations, can impact the composition and diversity of microbial communities in natural ecosystems such as soils, forests, and oceans. 12,[31][32][33] Recent findings have demonstrated that seasonal variation also significantly impacts microbial communities within humancontrolled systems, including jiang-flavored or fen-flavor baijiu fermentation, 21,34 vinegar fermentation 35 and kimchi fermentation. 36 In this study, we observed significant fluctuations in the microbial communities, encompassing ⊍and ⊎-diversity as well as composition within the SFB fermentation system across changing seasons.…”

“…Recent studies have shown that microbial communities in Chinese jiang-flavor, te-flavor, and light-flavor Baijiu fermentation differ in different seasons. 16,[20][21][22] However, the effects of seasonal changes on the microbiota and its metabolites in SFB fermentation have not been adequately clarified. Moreover, both deterministic and stochastic processes structure microbial communities simultaneously 23 but their importance in governing community assembly could be affected by many factors, such as seasonal changes.…”

“…Recent studies have shown that microbial communities in Chinese jiang ‐flavor, te ‐flavor, and light‐flavor Baijiu fermentation differ in different seasons 16,20‐22 . However, the effects of seasonal changes on the microbiota and its metabolites in SFB fermentation have not been adequately clarified.…”

Strategies and Challenges of Microbiota Regulation in Baijiu Brewing

“…The Daqu produced at different peak temperatures is used in the brewing of different types of Baijiu after maturation [ 29 ]. For example, high-temperature Daqu is mainly used in the production of sauce-flavor Baijiu [ 47 ]. Medium–high- and medium-temperature Daqu is often used in the brewing of strong-flavor Baijiu [ 48 ].…”