Deciphering the succession patterns of bacterial community and their correlations with environmental factors and flavor compounds during the fermentation of Zhejiang rosy vinegar

• Published in: International journal of food microbiology 2021-03, Vol.341, p.109070-109070, Article 109070
• Main Authors: Fang, Guan-Yu, Chai, Li-Juan, Zhong, Xiao-Zhong, Jiang, Yu-Jian
• Format: Article
• Language: English
• Subjects: Acetates - analysis; Acetic acid; Acetic Acid - metabolism; Acetobacter; Acetobacter - metabolism; Acetoin; Acetoin - analysis; Acids; Aroma compounds; Bacteria; Bacterial community; China; Co-occurrence network; Condiments - analysis; Condiments - microbiology; Correlation analysis; Ecological succession; Environmental factors; Ethanol; Ethyl acetate; Fermentation; Flavor compounds; Flavoring Agents - metabolism; Flavoring Agents - microbiology; Flavors; Gas Chromatography-Mass Spectrometry; Lactic acid; Lactobacillus; Lactobacillus - metabolism; Microbiota; Multivariate statistical analysis; Network analysis; Organic acids; Phenylethyl alcohol; Phenylethyl Alcohol - analysis; Relative abundance; Semisolids; Sequence analysis; Solid phase methods; Solid state fermentation; Structural equation model; Taste; Vinegar; Zhejiang rosy vinegar
• ISSN: 0168-1605; 1879-3460
• DOI: 10.1016/j.ijfoodmicro.2021.109070

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. •The main flavor compounds were acetic acid, lactic acid, ethyl acetate and acetoin.•Lactobacillus and Acetobacter respectively dominated the 0–30 days and 30–90 days.•Acetobacter and Lactobacillus were the major genera for the formation of flavor.•The abundant bacteria exhibited high correlations with other bacteria.•The environmental factors playing key roles in the fermentation.