title: Dynamics of microbial community during the extremely long-term fermentation process of a traditional soy sauce.
abstract: BACKGROUND
  Soy sauce produced by long-term natural fermentation is a traditional specialty in Asia, with a reputation for superior quality and rich flavour. In this study, both culture-dependent and culture-independent approaches were used to investigate the microbial diversity and community dynamics during an extremely long-term (up to 4 years) natural fermentation of Xianshi Soy Sauce, a national intangible cultural heritage.
  
  
  RESULTS
  Genera of Bacillus, Aspergillus and Cladosporium were detected by both methods above. The relative abundance of the genera Bacillus and Weissella was significantly higher in the late stage than in the early one, while the genera Klebsiella and Shimwellia were opposite (P < 0.05). For microbial community structure, subsequent analyses showed that obvious changes occurred with fermentation time, while there was a fair homogeneousness among samples of the same year, especially during the late fermentation stage.
  
  
  CONCLUSIONS
  The clustering analysis tended to separate the fermented mashes of the 4th year from the earlier stages, suggesting the necessity of the long fermentation period for developing distinctive microbiota and characteristic quality-related compounds. This is the first report to explore the temporal changes in microbial dynamics over a period of 4 years in traditional fermentation of soy sauce, and this work illustrated the importance of isolation of appropriate strains to be used as starter cultures in brewing processes. © 2016 Society of Chemical Industry.
authors.affiliation: Key laboratory of Bio-resources and Eco-environment of the Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Key laboratory of Bio-resources and Eco-environment of the Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China.|Luzhou Vacational and Technical College, Luzhou, Sichuan, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Deng
authors.affiliation: Key laboratory of Bio-resources and Eco-environment of the Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Yulan
authors.initials: Y
authors.lastname: Jin
authors.affiliation: Key laboratory of Bio-resources and Eco-environment of the Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Yanxi
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Key laboratory of Bio-resources and Eco-environment of the Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Baixue
authors.initials: B
authors.lastname: Xia
authors.affiliation: Key laboratory of Bio-resources and Eco-environment of the Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Qun
authors.initials: Q
authors.lastname: Sun
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D044822:Biodiversity; D005285:Fermentation; D045730:Soy Foods / Q000032:analysis / Q000382:microbiology*; D013025:Glycine max / Q000378:metabolism / Q000382:microbiology*; D013997:Time Factors
keywords: PCR-DGGE; long-term fermentation; microbial diversity; soy sauce; traditional manufacturing