本文研究了2008年7月黄海冷水团海域可培养细菌的多样性。AODC和DVC计数总菌数和活菌数分别为(1.3⁴.8)×105/mL和(0.6¹.6)×105/mL;2216E平板以菌落计数法可培养细菌浓度为(0.56².2)×103cfu/mL。从分离到的475株中选取163株进行16S rDNA扩增,并用HhaⅠ酶进行ARDRA(扩增性rDNA限制酶切片段分析)多态性分析,取114株不同带型测序。结果显示,冷水团细菌归为4个细菌类群:变形菌门(Proteobacteria)、放线菌门(Acti-nobacteria)、厚壁菌门(Firmicutes)和拟杆菌门(Bacteroidetes),共24个属,其中包括α-,β-,γ-变形菌纲;非冷水团细菌也归为这4个门类,共15个属,但未分离到β-变形菌纲。γ-变形菌纲在冷水团和非冷水团区域的不同深度都是优势菌群,不同的是冷水团区域α-变形菌纲比例较高(26.8%),而非冷水团区域α-变形菌纲比例相对较低(15.6%)。这表明黄海冷水团和非冷水团区域细菌多样性都很丰富,但其群落组成和优势菌群有所不同。此外,16S rDNA测序结果表明,6株细菌可能为海洋细菌新种。

Phylogenetic diversity of cultivable bacteria from the inter of the Yellow Sea Cold Water Mass(YSCWM) area was studied in July 2008,and was compared with that from the exterior of YSCWM area.Sea water samples were collected in five stations 3500-5,3600-6,3600-8,3400-6 and 3800-2 from the inter of YSCWM,and two stations 3200-3 and 3850-5 from the exterior of YSCWM.According to the AODC and DVC results,the total bacterial number and the total number of viable cells of the marine water samples were(1.3～4.8)×105/mL and(0.6¹.6)×105/mL,respectively;from the colony count method with 2216E plates,the abundance of the heterotrophic bacteria of sea water was(0.56².2)×103cfu/mL.475 bacterial strains were isolated from 2216E plates,and the PCR-ARDRA technique was performed on these strains for cluster analysis,with fragments of 16S rDNA digested by restriction enzyme HhaⅠ.The 16S rDNA of all major RFLP patterns were sequenced.Phylogenetic analysis of 114 bacterial strains showed that bacterial phylotypes from the inter of YSCWM were made up of four phyla bacteria,i.e.Proteobacteria,Actinobacteria,Firmicutes and Flavobacteria,including 24 genera,and from the exterior were made up of the same four taxon,including 15 genera.α-,β-and γ-Proteobacteria subdivisions of the Proteobacteria were discovered from the inter of YSCWM.However β-Proteobacteria was not discovered from the exterior of YSCWM.γ-Proteobacteria represented the vast majority of bacterial isolated at every depth.By comparing,α-Proteobacteria represented higher proportion with percentage of 26.8% inter of YSCWM and lower proportion with percentage of 15.6% exterior of YSCWM.These indicated that samples from the inter as well as the exterior of YSCWM showed high bacterial diversity,but bacterial community composition,as well as the predominant bacterial groups,from the inter of YSCWM was different from the exterior of YSCWM.In addition,according to the 16S rDNA gene sequences analysis,6 strains might be novel species.