应用PCR-DGGE技术分析黄海冷水团海域的细菌群落组成

Bacterial Community Composition of the Yellow Sea Cold Water Mass Studied by PCR-Denaturing Gradient Gel Electrophoresis

利用PCR-DGGE技术对2个季节（2006-04和2006-10）的黄海冷水团海域的细菌群落组成和优势菌群进行了分析.通过软件Glyko Bandscan分析DGGE图谱,4月份所有站位的条带数相近（约17条）,多样性丰富;10月份,在冷水团范围以内站位的条带约16条,其多样性也较丰富;而在冷水团范围以外站位的条带少（约12条）,其多样性较低.细菌16S rDNA V3区特征片段经DGGE分离、条带切割,共得到24条条带,克隆、测序后,进行系统进化分析,结果显示这24条带分别归属于2个细菌类群：变形细菌门（Proteobacteria）和拟杆菌门（Bacteroides）.在24条序列中有16条分别与变形细菌亚群的γ-和δ-Proteobacteria相似,有5条与拟杆菌门相似.时空分析发现,4月份所有站位水体（海水温度为7-12℃）的细菌群落组成和10月份（冷水团存在期）冷水团内部水体（海水温度低于10℃）的细菌群落组成相同（都包括γ-Proteobacteria、δ-Proteobacteria和Bacteroides）,与10月份冷水团外部水体（海水温度大于19℃）的（包括γ-Proteobacteria和Bacteroides）不同.优势菌群也存在同样的分布特点,4月份所有站位水体的优势菌群与10月份冷水团内部水体的优势菌群也相同（都是γ-Proteobacteria）,而10月份冷水团外部水体不同的站位优势菌群不同.该海域细菌群落组成和优势菌群的分布特点,可能与冷水团的形成有一定的相关性.

Bacterial community composition and predominant bacteria were analyzed by PCR-denaturing gradient gel electrophoresis（DGGE） in the Yellow Sea Cold Water Mass（YSCWM）.The results analysed by Glyko Bandscan software showed that samples from all stations in April and stations in the YSCWM area in October had almost the same number of different DNA bands（17 and 16 respectively） with high diversity.However,samples from the stations out of YSCWM area had fewer DNA bands（about 12） with lower diversity.24 DGGE bands reflecting varying phylotypes were excised,cloned and sequenced.Phylogenetic analysis of 24 cloned bands showed that bacterial phylotypes were made up of two phyla bacteria,Proteobacteria and Bacteroides.Among these sequences,16 were related to γ-Proteobacteria and δ-Proteobacteria and 5 were related to Bacteroides.It indicated that bacterial community composition,as well as the predominant bacterial groups,from all sampling stations in April（the temperature of seawater was around 7～12℃） and the inter of YSCWM in October（≤10℃） was the same,different from the exterior of YSCWM（≥19℃）.By comparing,from samples of exterior of YSCWM,the predominant bacteria groups were different with the different sampling stations.So it suggested that bacterial community composition and the characteristic of predominant bacteria of the YSCWM may have something to do with the development of the YSCWM.