大连两个海区海带相关可培养细菌群落分析

Culturable Bacteria Community Associated with Saccharina japonica from Two Sea Areas in Dalian

为研究大连两个海区海带相关可培养细菌群落,于2014年12月和2015年3月分别自登沙河湾和正明寺海带养殖区采集健康海带孢子体和海水,采用2216E涂布平板法,共分离出240株细菌,对所有菌株进行PCR和16S rDNA测序。结果表明,120条海带相关序列归属为4个门、5个纲、8个目、15个科、19个属、42个种;120条海水序列属于4个门、6个纲、10个目、18个科、26个属,46个种。在门水平,海带相关和海水细菌群落均可分为变形菌门、厚壁菌门、放线菌门和拟杆菌门,其中变形菌门和厚壁菌门为优势门。在属水平,海带相关优势属为嗜冷杆菌属、假单胞菌属、副球菌属和Salinibacterium;海水相关优势属为芽孢杆菌属、假单胞菌属、动球菌属、假交替单胞菌属和弧菌属。只从海带分离出的细菌属于微杆菌属、微小杆菌属、黄杆菌属、短小杆菌属、肠杆菌属、寡养单胞菌属和原小单孢菌属。Srensen指数表明,两个海区海带细菌群落有一定差异,不同海区海水及同一海区海带与海水细菌群落明显不同。

The aim of the study was to examine the bacterial community associated with the kelp Saccharina japonicafrom two sea areas in Dalian.In December 2014 and March 2015,a total of 240 isolates were obtained from the healthy kelp and the surrounding seawater collected from the sea areas of Dengshahe bay and Zhengmingsi using spread plate method relied on Zobell 2216 Emedium.Polymerase chain reaction and partial 16 SrDNA sequencing of DNA from all isolates revealed that 120 kelp-associated sequences were classified as 4 phyla,5 classes,8 orders,15 families,19 genera and 42 species;that 120 water-derived sequences were classified as 4 phyla,6 classes,10 orders,18 families,26 genera and 46 species.At phylum level,S.japonicaand seawater communities were composed of Proteobacteria,Firmicutes,Actinobacteria and Bacteroidetes,with dominant phyla of Proteobacteria and Firmicutes.At genus level,the composition of community associated with S.japonica was represented principally by Psychrobacter,Pseudomonas,Salinibacterium and Paracoccus;the seawater community was dominated by Bacillus,Pseudoalteromonas,Pseudomonas,Planococcus and Vibrio.Additionally,Microbacterium,Exiguobacterium,Flavobacterium,Curtobacterium,Enterobacter,Stenotrophomonas and Promicromonospora were exclusively present in community of S.japonica.As indicated by Srensen index,there were some differences in bacterial communities between kelp samples from the two different sea areas;while there existed significant differences in communities between seawater samples from the two sea areas and between kelp sample and seawater sample from the same sea area.