Selje Natascha, Simon Meinhard, Brinkhoff Thorsten
Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, PO Box 2503, D-26111 Oldenburg, Germany.
Nature. 2004 Jan 29;427(6973):445-8. doi: 10.1038/nature02272.
Bacterioplankton phylotypes of alpha-Proteobacteria have been detected in various marine regions, but systematic biogeographical studies of their global distribution are missing. Alpha-Proteobacteria comprise one of the largest fractions of heterotrophic marine bacteria and include two clades, SAR11 and Roseobacter, which account for 26 and 16% of 16S ribosomal RNA gene clones retrieved from marine bacterioplankton. The SAR11 clade attracted much interest because related 16S rRNA gene clones were among the first groups of marine bacteria to be identified by cultivation-independent approaches and appear to dominate subtropical surface bacterioplankton communities. Here we report on the global distribution of a newly discovered cluster affiliated to the Roseobacter clade, comprising only as-yet-uncultured phylotypes. Bacteria of this cluster occur from temperate to polar regions with highest abundance in the Southern Ocean, but not in tropical and subtropical regions. Between the south Atlantic subtropical front and Antarctica, we detected two distinct phylotypes, one north and one south of the polar front, indicating that two adjacent but different oceanic provinces allow the persistence of distinct but closely related phylotypes. These results suggest that the global distribution of major marine bacterioplankton components is related to oceanic water masses and controlled by their environmental and biogeochemical properties.
在不同的海洋区域均检测到了α-变形菌纲的浮游细菌系统发育型，但尚未有关于其全球分布的系统性生物地理学研究。α-变形菌纲是海洋异养细菌中占比最大的类群之一，包括两个进化枝，即SAR11和玫瑰杆菌，它们分别占从海洋浮游细菌中检索到的16S核糖体RNA基因克隆的26%和16%。SAR11进化枝引起了广泛关注，因为相关的16S rRNA基因克隆是最早通过非培养方法鉴定出的海洋细菌类群之一，并且似乎在亚热带表层浮游细菌群落中占主导地位。在此，我们报告了一个新发现的隶属于玫瑰杆菌进化枝的类群的全球分布情况，该类群仅包含尚未培养的系统发育型。这个类群的细菌分布于从温带至极地的区域，在南大洋中丰度最高，而在热带和亚热带区域则未检测到。在南大西洋亚热带锋面和南极洲之间，我们检测到了两个不同的系统发育型，一个在极锋以北，一个在极锋以南，这表明两个相邻但不同的海洋区域允许不同但密切相关的系统发育型持续存在。这些结果表明，主要海洋浮游细菌组分的全球分布与海洋水体有关，并受其环境和生物地球化学性质的控制。
