16S rDNA文库法分析草鱼肝胰脏和胆汁细菌群落组成

Analysis of the composition of bacterial communities in the hepatopancreas and bile of Ctenopharyngodon idellus through sequencing 16S rDNA library

利用16S rDNA文库随机测序法分析了草鱼肝胰脏和胆汁细菌菌落组成,结果表明,在肝胰脏中共鉴定出19种共生细菌,分别隶属于气单胞菌属、假单胞菌属、摩根菌属、不动杆菌属、弧菌属和变形杆菌属。气单胞菌属和假单胞菌属为优势属,气单胞菌属的丰度为36.17%,假单胞菌属为31.91%。其中,气单胞菌属的GZ16和假单胞菌属的GZ9菌株丰度最高,均为12.77%。在胆汁中共鉴定出10种共生细菌,分别隶属于气单胞菌属、假单胞菌属、摩根菌属和变形杆菌属。气单胞菌属和假单胞菌属为优势属,气单胞菌属的丰度为35%,假单胞菌属为27.5%。其中,变形杆菌属的DN1菌株丰度最高,为25%。肝胰脏中只有10.5%的细菌群落与胆汁的细菌群落相似,胆汁中只有20%的细菌群落与肝胰脏相似,表明草鱼肝胰脏和胆汁有各自特有的共生细菌群落。本研究结果,为进一步探讨肝胰脏和胆汁共生细菌的生理功能,以及细菌与宿主草鱼之间的协同进化提供了基础。

The bacterial diversity and community composition in hepatopancreas and bile of grass carp Ctenopharyngodon idellus were determined through seqencing the 16S rDNA gene library. The bacterial spectrum of hepatopancreas included eight species of Aeromonas,six species belonging to Pseudomonas,two species from Morganella,and one species each from Vibrio and Proteus. Aeromonas and Pseudomonas were two dominant genera with 36.17% and 31.91% relative abundance of community,respectively. Strains GZ16 of Aeromonas and GZ9 of Pseudomonas were two dominant species sharing same 12.77% relative abundance. The bacterial spectrum of bile included five species of Aeromonas,three species of Pseudomonas,and one species each from Morganella and Proteus. Same as found in hepatopancreas,Aeromonas and Pseudomonas were two dominant genera,sharing 35% and 27.5% relative abundance of community,respectively. Strain DN1 of Proteus was dominant species with 25% relative abundance of community. Comparative analysis showed that 10.5% community species in the hepatopancreas shared same as that in the bile,and 20% community species in the bile shared same as that in the hepatopancreas. This means there was a specific parasitic community in hepatopancreas or bile of grass carp. The results present in this research should be helpful to further understand the unknown roles of these bacteria in the hepatopancreas and bile,also to understand coevolution mechanism between bacterial community and host grass carp.