Diversity, ecology, and genomics of the Roseobacter clade: a short overview

Abstract

Due to worldwide distribution, high abundance and availability of physiologically diverse isolates the Roseobacter clade is one of the most intensively studied groups of marine bacteria. Organisms of this clade have been detected in a large variety of habitats, from coastal regions to deep-sea sediments and from polar ice to tropical latitudes, and constitute up to 25% of the total bacterial community. Use of a multitude of organic compounds, sulfur oxidation, aerobic anoxygenic photosynthesis, oxidation of carbon monoxide, DMSP demethylation, and production of secondary metabolites are some of the important traits found in this clade. Physiological characteristics and the different isolation sources indicate that organisms of the Roseobacter clade occupy various ecological niches. Since the first description of Roseobacter spp. in 1991, 38 affiliated and validated genera have been described. More than half of these descriptions have been published within the last 3 years. Genome sequencing of currently 40 different strains demonstrates enormous interest in the genetic and metabolic diversity of these bacteria. Plasmids with an enormous size range are also widespread in the Roseobacter clade indicating an adaptive genomic structure. Comparisons with other highly relevant groups, like the SAR11 clade, have shown drastic differences in genome organization.

Marine bacterial community structure resilience to changes in protist predation under phytoplankton bloom conditions

“…The resulting prevalence of Rhodobacteraceae in a community subjected to strong grazing pressure could be related to a smaller effect of HNF on this group compared with the others. However, as grazing losses did not seem to be phylotypespecific in this experiment, the resulting dominance of Rhodobacteraceae was most likely because of their reported genotypic and metabolic diversity (Brinkhoff et al, 2008) and their ability to take advantage of the environmental conditions associated with algal blooms (Eilers et al, 2001;Pinhassi et al, 2004;Allers et al, 2007;Baltar et al, 2007;Buchan et al, 2014) and the phytoplanktonderived DOC produced (Zubkov et al, 2001;Vila et al, 2004;Alonso and Pernthaler, 2006;Sarmento and Gasol, 2012), more than due to a superior grazing-avoidance capability. Thus, whether avoidance or lessening of grazing losses is a crucial ecological trait for bacteria, and thus a critical factor for the observed dominance of marine bacterial clusters such as Rhodobacteraceae, remains to be shown for marine systems.…”

Environmental proteomics of microbial plankton in a highly productive coastal upwelling system

“…Members of the Roseobacter clade have been isolated from a wide variety of habitats and are physiologically diverse (Brinkoff et al, 2008), with marine strains having unique traits in carbon and sulfur sequestration, such as aerobic anoxygenic photosynthesis, carbon monoxide oxidation and dimethylsulfoniopropionate degradation (Allgaier et al, 2003;Moran et al, 2003Moran et al, , 2004Miller and Belas, 2004). Although the most abundantly detected Roseobacter proteins, such as GroEL, TufB and ribosomal proteins, tended to have housekeeping functions, proteins involved in amino acid, sugar and proline/glycine betaine transport were also frequently observed.…”

Gene transfer agent (GTA) genes reveal diverse and dynamic Roseobacter and Rhodobacter populations in the Chesapeake Bay

“…The first complete genome sequence of a marine roseobacter, Silicibacter pomeroyi, was reported by Moran et al (2004), and there are now complete or draft genome sequences for ca. 40 marine roseobacters, representing diverse clusters (Brinkhoff et al, 2008). This information will facilitate studies of these important organisms at the genomic level.…”