Water mass and depth determine the distribution and diversity ofRhodobacteralesin an Arctic marine system

Abstract

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.

Genetic Diversity of Bacterial Communities and Gene Transfer Agents in Northern South China Sea

“…Studies on g5 genetic diversity have mainly focused on cold and temperate waters, such as the Subartic North Atlantic Ocean [6], Arctic marine [15], and Chesapeake Bay [5]. The overwhelming majority of g5 gene OTUs in the South China Sea was different from these areas.…”

“…Although the distribution of the Rhodobacterales community in cold waters and temperate coast has been reported [2], [5], [6], [14], [15], the members of Rhodobacterales in tropical waters have not been described in detail. This study aimed to (i) determine the bacterial community and relative abundance of Rhodobacterales in nSCS, (ii) analyze the diversity and spatial genetic variations of the g5 gene in nSCS, and (iii) compare g5 structure of the nSCS with those from other areas.…”

Structure and function of high Arctic pelagic, particle‐associated and benthic bacterial communities

“…Microbial communities in the Arctic Ocean are diverse, distinct from lower latitude communities and structured by a range of features (e.g., Boetius et al, 2015). In Arctic marginal seas and the western Arctic Ocean, microbial communities are shaped by spatial variations in physicochemical regimes in the Arctic water column (Galand et al, 2010;Kirchman et al, 2010;Bowman et al, 2012;Fu et al, 2013;Winter et al, 2013;Han et al, 2015). Strong temporal fluctuations in environmental conditions result in seasonal changes in community composition in the upper water column (Bano and Hollibaugh, 2002;Alonso-Sáez et al, 2014;Han et al, 2015).…”

Diversity of retrievable heterotrophic bacteria in Kongsfjorden, an Arctic fjord

“…A recent study from North Atlantic Ocean shows that distinct water bodies host different bacterial populations, which may serve as biological markers for oceanic provinces 40 . Similarly, Fu et al 41 found water mass to be the most important factor for the distribution of marine Rhodobacterales communities in the Arctic marine system. Thus, the increased population of H. titanicae could be due to the increased intrusion of Atlantic water into Kongsfjorden during this period.…”