生产季节对贮存期大曲的微生物群落结构和非挥发性代谢物组成的影响

Influence of Production Seasons on The Structure of Microbial Community and The Composition of Non-Volatile Metabolites in The Stored Daqu

目的:探究生产季节对贮存期大曲的微生物结构和非挥发性代谢物组成的影响。方法:采用16S rRNA及ITS高通量测序和非靶向代谢组学对秋夏生产的贮存期大曲进行分析。结果:不同季节生产的贮存期大曲的细菌菌属种类占比均差异显著,而真菌菌属仅占比差异显著且贮存之后其最优势菌属占比趋于一致。非靶向代谢组学共鉴定了157种非挥发性代谢物,包括小肽类、氨基酸及其衍生物以及醇醛酮等风味相关的物质,它们在夏季生产的贮存期大曲中的含量整体高于秋季生产的贮存期大曲。关联性分析显示,差异风味相关代谢物主要与被明显改变的细菌菌属呈显著正相关。结论:控制大曲生产季节可能主要影响大曲产香作用。研究结果可为大曲的生产控制提供有效指导。

The effect of production season on the microbial structure and composition of nonvolatile compounds in stored Daqu was investigated.Methods:16S rRNA and ITS high-throughput sequencing and label-free metabolomics were used to analyze stored Daqu produced in autumn and summer,respectively.Results:Genera and proportion of bacteria of stored Daqu produced in different seasons were both significantly different,while fungi only significantly differed in the proportion and the most dominant genus tended to be the same after storage.Label-free metabolomics identified 157 nonvolatile substances,including small peptides,amino acids and their derivatives,and alcohols,aldehydes and ketones,which are related to flavor.The content of these substances of stored Daqu produced in summer was overall higher than that of Daqu produced in autumn.Correlation analysis revealed that these differential metabolites were mainly positively correlated with the bacterial genera that were significantly altered.Conclusion:Controlling the season of production may mainly change the flavorproducing function of Daqu.Our study could provide an effective guidance for the production process controlof Daqu.