保温发酵鱼露中细菌群落的16S rDNA分子生态分析

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

本文通过对细菌16S rDNA V4区进行高通量测序,并结合实时荧光定量PCR法(FQ-PCR)研究35℃发酵条件下鱼露的细菌群落多样性。研究发现发酵初期细菌数量快速下降,到后期数量基本保持稳定。鱼露中细菌群落组成复杂,在测序得到的所有细菌OTUs中共注释出37个门、238个属,但有50%左右的OTUs未能注释到属。发酵8个月后,继续增加发酵时间,鱼露中的细菌组成变化不明显。在门的水平上,在鱼露发酵的各个阶段中细菌主要分布在变形菌门(Proteobacteria)和厚壁菌门(Firmicutes);在属分类的水平上,优势菌主要有乳杆菌属(Lactobacillus)、嗜冷杆菌属(Psychrobacter)、假单胞菌属(Pseudomonas)、链球菌属(Streptococcus)、不动菌属(Acinetobacter)等。发酵前2个月,优势菌是嗜冷杆菌属(Psychrobacter,23.39%)、链球菌属(Streptococcus,5.34%)、乳杆菌属(Lactobacillus,3.05%),发酵12个月时,主要优势菌中变形菌门中以链球菌属(Streptococcus,3.62%)、乳杆菌属(Lactobacillus,3.23%)、葡萄球菌属(Staphylococcus,1.20%)为主,而厚壁菌门以不动菌属(Acinetobacter,9.14%)、嗜冷杆菌属(Psychrobacter,8.77%)、假单胞菌属(Pseudomonas,6.78%)为主,其中耐盐和嗜盐的乳酸菌主要有乳杆菌属(Lactobacillus)、链球菌属(Streptococcus)等。

The diversity of bacterial community in fish sauce during fermentation at 35 ℃ was analyzed using high-through put sequencing targeting V4 region of 16 S 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(12 th 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.