工业化生产大豆酱微生物群落发酵演替规律及功能变化特征

Fermentation Succession of Microbial Community and Functional Changes in Industrialization Soybean Paste

目的:解析工业化生产大豆酱发酵周期阶段微生物群落的多样性、演替及差异转录基因功能性,探讨不同发酵阶段影响大豆酱风味品质的核心功能微生物,为合理地监测其发酵品质和生产稳定性,缩短发酵时间提供理论基础。方法:利用宏基因组测序技术分析大豆酱发酵过程中的微生物群落结构和演替规律,跟踪发酵过程中理化特性和挥发性风味物质变化,分析微生物群落和风味物质的相关性,对微生物的功能性进行预测。结果:发酵前期细菌和真菌微生物群落变化显著,后期变化逐渐趋于稳定。优势细菌主要为葡萄球菌属、四联球菌属、阪崎肠杆菌、乳杆菌属、魏斯氏菌属、肠杆菌属;优势真菌为接合酵母菌属和曲霉属。其中,葡萄球菌属和接合酵母菌属序列丰度随发酵时间延长不断增加;其余菌属的基因序列数量在发酵过程中更替变化。相关性分析表明,总酸、氨基酸态氮等理化因素对不同发酵时期的大豆酱具有一定影响,同时,优势微生物对大豆酱理化性质和风味发挥着不同的作用。结论:葡萄球菌属和接合酵母菌属与挥发性物质呈正相关,对挥发性醇酯类风味物质的形成起重要作用;曲霉属与总酸、蛋白酶和淀粉酶具有正相关性,葡萄球菌属促进氨基酸、醛酮类物质的合成。

Objective: The effect of influence the core functional microorganisms in different fermentation stages soybean paste of flavor and quality the diversity was studied by improving diversity succession and function of differentially transcribed genes of microbial community. Therefore, it provided theoretical basis for reasonably monitoring fermentation quality and production stability and shortening fermentation time. Methods: Microbial community structure and succession and predicting microbial function were used by metagenomic sequencing technology in industrialization soybean paste. And physical, chemical characteristics and volatile flavor were analyzed. Lastly, the correlation between microbial community and flavor substances was studied. Results: The microbial communities of bacteria and fungi changed significantly in the early fermentation stage, and gradually stabilized in the late fermentation stage. The dominant bacteria were Staphylococcus, Tetragenococcus, Cronobacter, Lactobacillus, Weissella and Enterobacter. The dominant fungi were Zygosaccharomyces and Aspergillus. The abundance of Staphylococcus and Zygosaccharomyces increased with the extension of fermentation time. The number of gene sequences of other bacteria changed during fermentation. Correlation analysis showed that physical and chemical factors(total acid and amino acid nitrogen) had a certain effect on the physical and chemical properties and flavor of soybean paste at different fermentation stages. Conclusion: Staphylococcus and Zygosaccharomyces were positively correlated with volatile compounds, and played an important role in the formation of volatile alcohol esters flavor substances. Aspergillus was positively correlated with total acid, protease and amylase, while Staphylococcus promoted the synthesis of amino acids, aldehydes and ketones.