双歧杆菌属天然质粒系统分类

【背景】以往双歧杆菌质粒分类学研究较少,双歧杆菌属质粒系统分类方法缺失。【目的】建立双歧杆菌属天然质粒系统分类和鉴定方法,促进质粒在双歧杆菌生物学研究中的理解和应用。【方法】利用质粒复制起始蛋白进化树和基因组共线性分析方法,对目前所有已测序的双歧杆菌属天然质粒进行系统分类研究。【结果】双歧杆菌所有已知天然质粒可以划分为6个不同类型的质粒家族和3个独特的复合质粒,家族Ⅲ和家族Ⅵ质粒可进一步划分为不同的亚型类群。家族Ⅲ质粒是双歧杆菌属天然质粒的主要类型和优势家族。家族Ⅵ质粒成员亚型分类最丰富。在质粒家族水平,2种方法的分类结果完全一致。【结论】本文揭示了所有分析质粒之间的系统分类关系,建立了双歧杆菌属天然质粒系统的分类标准、方法和体系,可为今后双歧杆菌天然质粒分类和鉴定提供重要的理论参考和分类依据。

Phylogenetic classification of natural plasmids in Bifidobacterium

Background] In the past, there were few studies on the taxonomy of bifidobacteria plasmids, and the phylogenetic classification method of Bifidobacterium plasmid was missing. Objective] In order to establish a method for phylogenetic classification and identification of natural plasmids in Bifidobacterium, and increase understanding and application of plasmids in the research of bifidobacteria biology. Methods] We conducted to phylogenetic classification of all sequenced plasmids in Bifidobacterium by the analysis of phylogenetic relationship of replication initiation protein and genome colinearity. Results] All known natural plasmids of Bifidobacterium were divided into six different types of plasmid families and three unique complex plasmids. Plasmids of type III and VI family were further divided into different subtype groups. Plasmids of the type III and VI family can be further divided into different subtype groups. Plasmids of the type III family were the main type and dominant family of natural plasmids in Bifidobacterium. Plasmid subtypes of type VI family were most abundantly classified. At the plasmid family level, the classification results of the two methods were completely identical. Conclusion] These results comprehensively and accurately revealed the phylogenetic classification relationship between all the plasmids that were analyzed, and established the phylogenetic classification standard and method of natural plasmids in Bifidobacterium, which provided important theoretical references and classification basis for the future classification and identification of natural plasmids in Bifidobacterium.