Deciphering the Composition and Functional Profile of the Microbial Communities in Chinese Moutai Liquor Starters
Deciphering the Composition and Functional Profile of the Microbial Communities in Chinese Moutai Liquor Starters
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DOI：
10.3389/fmicb.2019.01540
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发表时间：
2019-07-04
影响因子：
5.2
通讯作者：
Liu, Huan
中科院分区：
文献类型：
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作者：
Gan, Shu-Heng;Yang, Fan;Liu, Huan
茅台酒是世界著名的中国传统白酒，具有复杂的口感和香气，而发酵剂（大曲）的质量对其影响很大。然而，微生物群落在发酵剂中的作用尚未完全了解。在这项研究中，我们揭示了185个茅台酒发酵剂样品的微生物组成，涵盖了未成熟和成熟阶段的三种不同类型的发酵剂，以及成熟发酵剂微生物组的功能基因组成。结果表明，未成熟发酵剂的微生物组成模式各不相同，但经过半年的储存和随后的混合，它们最终成为成熟发酵剂时是相似的和稳定的。为了帮助识别两种类型的未成熟启动子，我们通过留一法交叉验证（LOOCV）选择了七个操作分类单位（OTU）标记，并且分类为多孢菌属的OTU是最具决定性的一个。对于成熟的发酵剂，我们确定了总共16个核心OTU，其中一个注释为芽孢杆菌，发现与糖化力正相关。我们还确定了淀粉和纤维素水解途径的功能基因和微生物组成。具有较高丰度的α-葡萄糖苷酶、α-淀粉酶和葡萄糖淀粉酶的微生物可能有助于高糖化力。本研究揭示了茅台酒曲不同阶段的微生物群落特征，加深了对微生物区系与曲剂功能特性关系的认识。
Moutai is a world-famous traditional Chinese liquor with complex taste and aroma, which are considered to be strongly influenced by the quality of fermentation starters (Daqu). However, the role of microbial communities in the starters has not been fully understood. In this study, we revealed the microbial composition of 185 Moutai starter samples, covering three different types of starters across immature and mature phases, and functional gene composition of mature starter microbiome. Our results showed that microbial composition patterns of immature starters varied, but they eventually were similar and steady when they became mature starters, after half-year storage and subsequent mixing. To help identify two types of immature starters, we selected seven operational taxonomic unit (OTU) markers by leave-one-out cross validation (LOOCV) and an OTU classified as Saccharopolyspora was the most decisive one. For mature starters, we identified a total of 16 core OTUs, one of which annotated as Bacillus was found positively associated with saccharifying power. We also identified the functional gene and microbial composition in starch and cellulose hydrolysis pathways. Microbes with higher abundances of alpha-glucosidase, alpha-amylase, and glucoamylase probably contributed to high saccharifying power. Overall, this study reveals the features of Moutai starter microbial communities in different phases and improves understanding of the relationships between microbiota and functional properties of the starters.