Data_Sheet_1_Integrative Metagenomics–Metabolomics for Analyzing the Relationship Between Microorganisms and Non-volatile Profiles of Traditional Xiaoqu.PDF

Xiaoqu, one of three traditional jiuqu in China, is a saccharifying and fermenting agent used in Xiaoqu jiu brewing, with different ingredient compositions and preparation techniques used in various regions. The yield and quality of Xiaoqu jiu are significantly affected by the metabolites and microbiota of Xiaoqu; however, the associated relationship remains poorly understood. This study aimed to analyze this relationship in three typical traditional Xiaoqu from the Guizhou province in China. The non-volatile metabolites of Xiaoqu were detected using gas chromatography time-of-flight mass spectrometry, whereas the classification and metabolic potential of the microbiota were investigated using metagenomic sequencing. Results show that Firmicutes, Proteobacteria, and Actinobacteria represent the dominant bacterial phyla, with Lactobacillus, Bacillus, Acinetobacter, Leuconostoc, and Weissella found to be the dominant bacterial genera. Meanwhile, Ascomycota, Mucoromycota, and Basidiomycota are the dominant fungal phyla with Aspergillus, Saccharomyces, Pichia, Rhizopus, and Phycomyces being the predominant fungal genera. Functional annotation of the microbiota revealed a major association with metabolism of carbohydrates, cofactors, and vitamins, as well as amino acids. A total of 39 significantly different metabolites (SDMs) were identified that are involved in 47 metabolic pathways, primarily that of starch and sucrose; glycine, serine, and threonine; glyoxylate and dicarboxylate; pyruvate; as well as biosynthesis of pantothenate and CoA. Further, based on Spearman's correlation analysis, Aspergillus, Saccharomyces, Lactobacillus, Acetobacter, Weissella, Pantoea, Desmospora, and Bacillus are closely correlated with production of physicochemical indexes and SDMs. Moreover, the metabolic network generated for the breakdown of substrates and formation of SDMs in Xiaoqu was found to primarily center on the metabolism of carbohydrates and the tricarboxylic acid cycle. These results provide insights into the functional microorganisms and metabolic patterns present in traditional Guizhou Xiaoqu and might guide researchers in the production of stable and efficient Xiaoqu in the future.

小曲（Xiaoqu）是中国三大传统酒曲之一，是小曲酒（Xiaoqu jiu）酿造所用的糖化发酵剂，不同地区的小曲其原料组成与制备工艺各有差异。小曲酒的产量与品质受小曲代谢物及微生物群的显著影响，但二者间的关联机制至今仍未得到充分阐明。本研究针对中国贵州省的三款典型传统小曲，旨在解析二者间的关联关系。本研究采用气相色谱-飞行时间质谱（gas chromatography time-of-flight mass spectrometry）检测小曲中的非挥发性代谢物，并通过宏基因组测序（metagenomic sequencing）分析微生物群的分类组成与代谢潜力。研究结果显示，优势细菌菌门为厚壁菌门（Firmicutes）、变形菌门（Proteobacteria）与放线菌门（Actinobacteria），优势细菌属则包括乳杆菌属（Lactobacillus）、芽孢杆菌属（Bacillus）、不动杆菌属（Acinetobacter）、明串珠菌属（Leuconostoc）以及魏斯氏菌属（Weissella）。与此同时，优势真菌菌门为子囊菌门（Ascomycota）、毛霉门（Mucoromycota）与担子菌门（Basidiomycota），优势真菌属则包含曲霉属（Aspergillus）、酿酒酵母属（Saccharomyces）、毕赤酵母属（Pichia）、根霉属（Rhizopus）以及绵霉属（Phycomyces）。对微生物群的功能注释结果显示，其主要参与碳水化合物、辅因子与维生素以及氨基酸的代谢过程。本研究共鉴定出39种显著差异代谢物（significantly different metabolites, SDMs），它们参与47条代谢通路，主要包括淀粉与蔗糖代谢、甘氨酸-丝氨酸-苏氨酸代谢、乙醛酸与二羧酸代谢、丙酮酸代谢以及泛酸和辅酶A生物合成通路。进一步通过斯皮尔曼相关性分析（Spearman's correlation analysis）发现，曲霉属、酿酒酵母属、乳杆菌属、醋杆菌属（Acetobacter）、魏斯氏菌属、泛菌属（Pantoea）、德莫斯氏菌属（Desmospora）以及芽孢杆菌属与各项理化指标及显著差异代谢物的生成密切相关。此外，针对小曲中底物降解与显著差异代谢物生成所构建的代谢网络显示，其核心通路主要为碳水化合物代谢与三羧酸循环（tricarboxylic acid cycle）。本研究结果为解析贵州传统小曲中的功能微生物与代谢模式提供了理论参考，同时可为未来实现稳定高效的小曲生产提供研究指导。