16S rDNA-based Analysis of Bacterial Community in Fish Sauce during Temperature-controlled Fermentation

The diversity of bacterial community in fish sauce during fermentation at 35 ℃ was analyzed using high-through put sequencing targeting V4 region of 16S rDNA and real-time fluorescent quantitative PCR(FQ-PCR)method. The results showed that the bacterial population declined rapidly at the initial stage of fermentation and remained constant at later stage. The bacterial community in fish sauce was very complex. Total 37 phylums and 238 genera were annotated from all the bacterial OTUs,but about 50% of OTUs couldn’t be annotated to genus level. The bacterial community didn’t change significantly with the extension of time after eight-month fermentation. During the whole fermentation,most of the detected bacteria belonged to the two phylums of Proteobacteria and Firmicutes and the genera of Lactobacillus,Psychrobacter,Pseudomonas,Streptococcus,Acinetobacter and others. During the initial 2 months,Psychrobacter(23.39%),Streptococcus(5.34%),Lactobacillus(3.05%)were dominant. At the end of fermentation(12th month),the dominant bacteria in Proteobacteria were Streptococcus(3.62%),Lactobacillus(3.23%),Staphylococcus(1.20%),and in Firmicutes were Acinetobacter(9.14%),Psychrobacter(8.77%)and Pseudomonas(6.78%). The salt-resistant or halophilic lactic acid bacteria were mainly Lactobacillus and Streptococcus and others.