萝卜泡菜细菌多样性的高通量测序分析

本文基于Illumina平台的高通量测序,解析萝卜泡菜发酵液中亚硝酸盐浓度峰值期(第3 d)和回落期(第7 d)时细菌群落结构多样性。亚硝酸盐浓度峰值期和回落期样品中分别得到373和349个可操纵分类单元(OTU),分属于135和127个细菌属,且峰值期细菌群落丰富度、多样性以及均匀度指数均高于回落期。峰值期发酵液样品中以变形菌门细菌(相对丰度72.1%)最为优势,以Erwinia(45.0%)、Aeromonas(7.4%)、Pseudomonas(6.6%)、Shigella(6.0%)和Delftia(5.1%)为主要优势菌属。厚壁菌门(18.9%)为第二优势菌门,Lactococcus(10.5%)为其中的主要优势属。回落期发酵液样品中以厚壁菌门(84.0%)最为优势,优势属包括明Leuconostoc(27.5%)、Lactococcus(19.9%)、Weissella(19.2%)和Pediococcus(16.3%)等。而变形菌门相对丰度降为10.5%。结果表明伴随着亚硝酸盐浓度变化,萝卜泡菜发酵过程中细菌群落结构多样性也发生演替,与发酵液中亚硝酸盐的形成和降解密切相关。

The Analysis of Microbial Diversity in the Fermentation Broth of Pickled Radish Based on the High-throughput DNA Sequencing

Based on the high-throughput DNA sequencing of Illumina, the diversity of microbial community composition in the fermentation broth of the pickled radish during the peak value period (3rd day) and the background value period (7th day) of nitrite concentration was entirely clarified in this study. Total 373 and 349 bacterial operational taxonomic units (OTU) were obtained from the samples on the 3rd and 7th day, which belonged to 135 and 127 bacterial genus, respectively. The Chao1 index, richness index and diversity index of bacterial community in the samples on the 3rd were higher than that on the 7th day. In the samples on the 3rd day, the bacterial phylum Proteobacteria was the most dominant group (72.1%), and Erwinia, Aeromonas, Pseudomonas, Shigella and Delftia were the main genus of 45.0%, 7.4%, 6.6%, 6.0% and 5.1%, respectively. The bacterial phylum Firmicutes was the second dominant group (18.9%), and the genus Lactococcus was the main genus of 10.5%. In the samples on the 7th day, the bacterial phylum Firmicutes was the most dominant group (84.0%), and Leuconostoc, Lactococcus, Weissella and Pediococcus were the main genus of 27.5%, 19.9%, 19.2% and 16.3%, respectively. The relative abundance of the previous dominant phylum Proteobacteria decreased to 10.5%, and the relative abundance of all genuses were below to 2%. The results indicated that the diversity of bacterial community in the fermentation broth of the pickled radish might shift following the change of the nitrite concentration, which was closely related to the formation and degradation of nitrite in the fermentation broth.