Department of Biology, Memorial University of Newfoundland, St. John's, NF, Canada.
FEMS Microbiol Ecol. 2013 Jun;84(3):564-76. doi: 10.1111/1574-6941.12085. Epub 2013 Feb 27.
Marine Rhodobacterales are recognized as a widespread, abundant, and metabolically versatile bacterial group in the world's oceans. They also show a nearly universal conservation of the genes for production of gene transfer agents (GTAs), virus-like particles that mediate genetic exchange between cells. It is not yet clear what factors determine the distribution of the various taxonomic subgroups of this order. To address this question, we analyzed the Rhodobacterales communities in 10 seawater samples from northern Baffin Bay collected during September 2008. A conserved gene from the GTA gene cluster was used to characterize the Rhodobacterales community structure. A total of 320 clones from 10 clone libraries were sequenced, and 22 operational taxonomic units representing putative species and 13 clusters representing putative genera were identified. A cluster related to Octadecabacter comprised 59% of total clones from the northern Baffin Bay. Phylogenetic analysis of the clones showed that the Rhodobacterales communities had distinct compositions in the different water masses that were sampled. A change in community structure related to depth was also observed. Therefore, in northern Baffin Bay where two ocean currents meet and mix, the Rhodobacterales community structures were primarily determined by water mass and depth.
海洋红杆菌目细菌被认为是海洋中广泛存在、丰富且代谢多样的细菌群体。它们还表现出几乎普遍保守的基因，用于生产基因转移剂（GTAs），即介导细胞间遗传交换的病毒样颗粒。目前尚不清楚哪些因素决定了该目各个分类亚群的分布。为了解决这个问题，我们分析了 2008 年 9 月在巴芬湾北部采集的 10 个海水样本中的红杆菌目群落。使用 GTA 基因簇中的保守基因来描述红杆菌目群落结构。从 10 个克隆文库中共测序了 320 个克隆，鉴定出了代表假定种的 22 个操作分类单元和代表假定属的 13 个聚类。与 Octadecabacter 相关的聚类占巴芬湾北部总克隆的 59%。克隆的系统发育分析表明，在采样的不同水团中，红杆菌目群落具有不同的组成。还观察到与深度相关的群落结构变化。因此，在两股海流相遇和混合的巴芬湾北部，红杆菌目群落结构主要由水团和深度决定。
