北欧海海水可培养细菌多样性

Diversity of culturable bacterial in the surface seawater of the Nordic Sea

【目的】为了解北欧海表层海水可培养细菌多样性与所在水文环境的关系。【方法】利用2216E、R2A和海水培养基对该海域暖流区、寒流区、海盆区及交汇区等多个区域不同站位的表层海水样品中的可培养细菌进行分离培养,通过16S r RNA基因测序对分离的菌株进行分类鉴定,并构建系统发育树进行系统发育分析。【结果】从北欧海表层海水中共分离到407株细菌,通过RFLP分析选取其中154株进行测序,结果表明此154株细菌分属于3个门,18个属,27个种。3个门包括变形菌门、厚壁菌门和放线菌门,优势属为假交替单胞菌属、嗜冷杆菌属等,优势种为食琼脂假交替单胞菌、海雪嗜冷杆菌等,并分离到闪烁交替单胞菌等多株嗜冷菌。比较不同区域的微生物多样性可以看出,γ-变形菌纲的细菌在各个区域均占较高比例。交汇区的细菌多样性最高,分离到了10个不同属的细菌,而海盆区细菌多样性最低,只分离到了4种。除了海盆区外,其他3个区域的样品中都分离到了特有的类群。【结论】从以上结果可以看出,北欧海域有较为丰富的微生物资源,且交汇区微生物多样性较其他区域高。

[Objective] The aim of this study was to understand the relationship between the diversity of culturable bacteria in the surface seawater and the hydrological environment.[Methods] We used MA,R2A and seawater medium to isolate bacteria from four different hydrological environments：the warm area,the cold area,the basin area and the intersection area.16 S rRNA was sequenced for classification and identification of the isolates,and phylogenetic tree was built for phylogenetic analysis.[Results] In total 407 bacteria were isolated from the samples and 154 strains were selected and sequenced by the Restriction Fragment Length Polymorphism analysis.These 154 strains were divided into 3 phyla,18 genera and 27 species.The 3 phyla were Proteobacteria,Firmicutes and Actinobacteria.The dominant genera were Pseudoalteromonas,Psychrobacter,ect.The dominant species were Pseudoalteromonas agarivorans,Psychrobacter nivimaris,ect.And several psychropliles bacteria were separated such as Alteromonas fuliginea.Compared the bacterial diversity among different regions,γ-proteobacteria was dominant in all the four areas,and the bacterial diversity of intersection area was the highest,where 10 different genera were isolated.Bacterial diversity of basic area was the lowest,only had 4.In addition to the basin area,special species were isolated from the samples in other 3 areas.[Conclusion] Nordic Sea is rich in microbial resources,and the microbial diversity in the intersection area is higher than that in other regions.