Deciphering microbial community dynamics along the fermentation course of soy sauce under different temperatures using metagenomic analysis

Bioscience of Microbiota, Food and Health

article

Nguyen Thanh Hai NGUYEN¹  Ming Ban HUANG¹  Fa Yong LIU²  Wei-Ling HUANG¹  Huyen-Trang TRAN³  Tsai-Wen HSU⁴  Chao-Li HUANG⁵  Tzen-Yuh CHIANG¹ 

[1] Department of Life Sciences, National Cheng Kung University, No.1 University Road East District;Department of Food Processing, National Tseng-Wen Agricultural and Industrial High School;Department of Biology, Institute of Natural Science Education, Vinh University;Endemic Species Research Institute;Institute of Tropical Plant Sciences and Microbiology, National Cheng Kung University, No.1 University Road East District Tainan 701

关键词: Aspergillus;    lactic acid bacteria (LAB);    metagenomics;    microbial succession;    soy sauce;   

DOI  :  10.12938/bmfh.2022-012

学科分类：生物科学（综合）

来源: Nihon Bifizusukin Senta / Japan Bifidus Foundation

【 摘 要 】

Fermented soy sauce consists of microorganisms that exert beneficial effects. However, the microbial community dynamics during the fermentation course is poorly characterized. Soy sauce production is classified into the stages of mash fermentation with koji (S0), brine addition (S1), microbial transformation (S2), flavor creation (S3), and fermentation completion (S4). In this study, microbial succession was investigated across stages at different temperatures using metagenomics analyses. During mash fermentation, Aspergillus dominated the fungal microbiota in all stages, while the bacterial composition was dominated by Bacillus at room temperature and by a diverse composition of enriched lactic acid bacteria (LAB) at a controlled temperature. Compared with a stable fungal composition, bacterial dynamics were mostly attributable to fluctuations of LAB, which break down carbohydrates into lactic acid. After adding brine, increased levels of Enterococcus and decreased levels of Lactococcus from S1 to S4 may reflect differences in salinity tolerance. Staphylococcus, as a fermentation starter at S0, stayed predominant throughout fermentation and hydrolyzed soybean proteins. Meanwhile, Rhizopus and Penicillium may improve the flavor. The acidification of soy sauce was likely attributable to production of organic acids by Bacillus and LAB under room temperature and controlled temperature conditions, respectively. Metagenomic analysis revealed that microbial succession was associated with the fermentation efficiency and flavor enhancement. Controlled temperature nurture more LAB than uncontrolled temperatures and may ensure the production of lactic acid for the development of soy sauce flavor.

【 授权许可】

CC BY