Deciphering the succession patterns of bacterial community and their correlations with environmental factors and flavor compounds during the fermentation of Zhejiang rosy vinegar
Deciphering the succession patterns of bacterial community and their correlations with environmental factors and flavor compounds during the fermentation of Zhejiang rosy vinegar
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DOI：
10.1016/j.ijfoodmicro.2021.109070
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发表时间：
2021-01-24
影响因子：
5.4
通讯作者：
Jiang, Yu-Jian
中科院分区：
文献类型：
--
作者：
Fang, Guan-Yu;Chai, Li-Juan;Jiang, Yu-Jian
浙江玫瑰醋是中国东南部的一种传统调味品，在开放的环境下采用半固态发酵技术生产，但对其风味形成的功能微生物群知之甚少。本研究采用HS-SPME/GC-MS联用技术，共鉴定出43种挥发性风味物质，主要包括乙酸乙酯(发酵结束时相对含量为1104.1 mg/L)、苯乙醇(417.6 mg/L)和乙酸乙酯(605.2 mg/L)。最丰富的有机酸是醋酸(59.6g/L)，在发酵过程中一直在上升，其次是乳酸(7.0g/L)，呈持续下降趋势。扩增产物序列分析表明，细菌群落的丰富度和多样性在发酵初期最高，然后在整个发酵过程中保持下降趋势。优势菌主要分布在醋酸菌(平均相对丰度为63.7%)和乳杆菌(19.8%)。测序和培养依赖分析表明，乳酸菌在发酵初期(第10~30天)占优势，而醋酸菌从40天一直保持较高的丰度。Spearman相关分析表明，可能参与风味物质形成的主要类群是醋酸杆菌和乳杆菌，通过共生网络分析也表明它们与其他细菌有很强的亲缘关系(边缘附着在醋酸杆菌上的占61.7%，乳杆菌占14.0%)。此外，结构方程模型表明，乙醇、可滴定酸和还原糖的含量是影响发酵过程中细菌群落演替及其代谢的主要环境因素。总体而言，这些发现阐明了细菌群落和风味化合物的动态分布以及潜在的功能微生物，有望帮助我们了解ZRV风味物质的形成。
Zhejiang Rosy Vinegar (ZRV) is a traditional condiment in Southeast China, produced using semi-solid-state fermentation techniques under an open environment, yet little is known about the functional microbiota involved in the flavor formation of ZRV. In this study, 43 kinds of volatile flavor substances were identified by HS-SPME/GC-MS, mainly including ethyl acetate (relative content at the end of fermentation: 1104.1 mg/L), phenylethyl alcohol (417.6 mg/L) and acetoin (605.2 mg/L). The most abundant organic acid was acetic acid (59.6 g/L), which kept rising during the fermentation, followed by lactic acid (7.0 g/L), which showed a continuously downward trend. Amplicon sequencing analysis revealed that the richness and diversity of bacterial community were the highest at the beginning and then maintained decreasing during the fermentation. The predominant bacteria were scattered in Acetobacter (average relative abundance: 63.7%) and Lactobacillus (19.8%). Both sequencing and culture-dependent analysis showed Lactobacillus dominated the early stage (day 10 to 30), and Acetobacter kept highly abundant from day 40 to the end. Spearman correlation analysis displayed that the potential major groups involved in the formation of flavor compounds were Acetobacter and Lactobacillus, which were also showed strong relationships with other bacteria through co-occurrence network analysis (edges attached to Acetobacter: 61.7%; Lactobacillus: 14.0%). Moreover, structural equation model showed that the contents of ethanol, titratable acid and reducing sugar were the major environmental factors playing essential roles in influencing the succession of bacterial community and their metabolism during the fermentation. Overall, these findings illuminated the dynamic profiles of bacterial community and flavor compounds and the potential functional microbes, which were expected to help us understand the formation of flavor substances in ZRV.