Open AccessCharacterization of bacterial community and flavor differences of different types of Douchi
Author(s) -
Wang Yurong,
Xiang Fanshu,
Zhang Zhendong,
Hou Qiangchuan,
Guo Zhuang
Publication year - 2021
Publication title -
food science and nutrition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.614
H-Index - 27
ISSN - 2048-7177
DOI - 10.1002/fsn3.2280
Subject(s) - firmicutes , food science , biology , weissella , proteobacteria , microorganism , actinobacteria , microbiology and biotechnology , bacteria , fermentation , 16s ribosomal rna , leuconostoc , lactobacillus , genetics
According to the appearance and technology, traditional fermented Douchi can be divided into dried Douchi and wet Douchi. However, there are few reports on the difference of bacterial community structure between them or the influence of bacterial community on product flavor. In this study, high‐throughput sequencing technology and electronic nose were used to measure the bacterial diversity and flavor of 40 Douchi samples, and the correlation between them was explored by multivariate statistical means combined with COG database. Results showed that the cumulative average relative abundance of Firmicutes and Proteobacteria in the samples was as high as 95.93%, and the former was the core bacteria phylum. On the whole, the dominant bacteria in Douchi were Bacillus (50.67%), Staphylococcus (14.07%), Enterococcus (2.54%), Proteus (1.61%), Brevibacillus (1.46%), Providencia (1.26%), Weissella (1.24%), and Ureibacillus (1.19%). LEfSe analysis indicated that Bacillus can be used as a biomarker in dried fermented soybeans. Meanwhile, dried samples contained more intensive aromatic substances, but were significantly lower in W6S (selectivity to hydrogen) and W3S (methane‐aliph) compared with the wet samples. Aneurinibacillus and Brevibacillus were helpful to the formation of aromatic flavor in Douchi, but Vagococcus and Corynebacterium were the opposite. Gene and microbial phenotypic prediction showed that microorganisms in dried Douchi use protein more efficiently, while in wet Douchi, microbial energy metabolism was more vigorous. The pathogenic potential of microorganisms in dried samples was higher than that in wet. This study can sound the alarm for improving the safety of home‐brewed Douchi and provide guidance for the subsequent screening of strains that enhance the flavor of fermented soybeans.