SAR11 marine bacteria require exogenous reduced sulphur for growth

Tripp, H. James; Kitner, Joshua B.; Schwalbach, Michael S.; Dacey, John W. H.; Wilhelm, Larry J.; Giovannoni, Stephen J.

doi:10.1038/nature06776

Cited by 347 publications

(332 citation statements)

References 29 publications

Supporting

Mentioning

304

Contrasting

Unclassified

Order By: Relevance

“…Kiene et al (1999) hypothesized that the enzyme cystathionine gammasynthase (metB) could be responsible for methionine synthesis from DMSP by O-acyl homoserine based on studies with cultured roseobacters, with cysteine subsequently synthesized from methionine. Experimental evidence with isolates of SAR11 that lack genes for the assimilatory sulfate reduction pathway agrees that synthesis of methionine followed by conversion to cysteine might be a common pathway for DMSP-S assimilation, as cysteine itself was unable to support SAR11 growth (Tripp et al, 2008). In contrast, we found that transcripts related to the cysteine synthesis pathway (cysteine synthase (COG0031) and O-acetylhomoserine sulfhydrylase (COG2873, Supplementary Table S4)) were significantly enriched after DMSP addition.…”

Section: Discussioncontrasting

confidence: 42%

“…SAR11 members were the most abundant taxon in the bacterial assemblage based on PCR-amplified 16S rRNA genes (Figure 4), but were poorly represented in the DMSP-related transcript pool. As the ability of SAR11 members to assimilate DMSP has been shown (Malmstrom et al, 2004b;Tripp et al, 2008), they may have responded more slowly than other groups to the DMSP addition, or the concentration used here (25 nM compared with typical DMSPd concentrations of 3-6 nM; Kiene and Slezak, 2006) might have saturated their transport systems. The fact that DMSP concentrations were still high in the experimental treatment at the time of RNA collection for sequencing (28 nM) suggests that bacterioplankton transcriptional responses should be ongoing at the time of sample collection.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Transcriptomic analysis of a marine bacterial community enriched with dimethylsulfoniopropionate

et al. 2010

View full text Add to dashboard Cite

Dimethylsulfoniopropionate (DMSP) is an important source of reduced sulfur and carbon for marine microbial communities, as well as the precursor of the climate-active gas dimethylsulfide (DMS). In this study, we used metatranscriptomic sequencing to analyze gene expression profiles of a bacterial assemblage from surface waters at the Bermuda Atlantic Time-series Study (BATS) station with and without a short-term enrichment of DMSP (25 nM for 30 min). An average of 303 143 reads were obtained per treatment using 454 pyrosequencing technology, of which 51% were potential protein-encoding sequences. Transcripts from Gammaproteobacteria and Bacteroidetes increased in relative abundance on DMSP addition, yet there was little change in the contribution of two bacterioplankton groups whose cultured members harbor known DMSP degradation genes, Roseobacter and SAR11. The DMSP addition led to an enrichment of transcripts supporting heterotrophic activity, and a depletion of those encoding light-related energy generation. Genes for the degradation of C3 compounds were significantly overrepresented after DMSP addition, likely reflecting the metabolism of the C3 component of DMSP. Mapping these transcripts to known biochemical pathways indicated that both acetyl-CoA and succinyl-CoA may be common entry points of this moiety into the tricarboxylic acid cycle. In a short time frame (30 min) in the extremely oligotrophic Sargasso Sea, different gene expression patterns suggest the use of DMSP by a diversity of marine bacterioplankton as both carbon and sulfur sources.

show abstract

Section: Discussioncontrasting

confidence: 42%

Section: Discussionmentioning

confidence: 99%

Transcriptomic analysis of a marine bacterial community enriched with dimethylsulfoniopropionate

et al. 2010

View full text Add to dashboard Cite

show abstract

“…The unusual requirements of SAR11 for reduced sulfur compounds (Tripp et al, 2008a) and glycine or serine (Tripp et al, 2008b) may play a role in spatial and temporal control of SAR11 populations, although too little chemical data exists at present to test this hypothesis. The proteome composition of SAR11 appears to be another facet of a survival strategy related to small cell dimensions (Sowell et al, 2008).…”

Section: Geochemical Patterns At Bats and Sar11 Metabolismmentioning

confidence: 99%

Seasonal dynamics of SAR11 populations in the euphotic and mesopelagic zones of the northwestern Sargasso Sea

et al. 2008

View full text Add to dashboard Cite

Bacterioplankton belonging to the SAR11 clade of a-proteobacteria were counted by fluorescence in situ hybridization (FISH) over eight depths in the surface 300 m at the Bermuda Atlantic Timeseries Study (BATS) site from 2003 to 2005. SAR11 are dominant heterotrophs in oligotrophic systems; thus, resolving their temporal dynamics can provide important insights to the cycling of organic and inorganic nutrients. This quantitative time-series data revealed distinct annual distribution patterns of SAR11 abundance in the euphotic (0-120) and upper mesopelagic (160-300 m) zones that were reproducibly correlated with seasonal mixing and stratification of the water column. Terminal restriction fragment length polymorphism (T-RFLP) data generated from a decade of samples collected at BATS were combined with the FISH data to model the annual dynamics of SAR11 subclade populations. 16S rRNA gene clone libraries were constructed to verify the correlation of the T-RFLP data with SAR11 clade structure. Clear vertical and temporal transitions were observed in the dominance of three SAR11 ecotypes. The mechanisms that lead to shifts between the different SAR11 populations are not well understood, but are probably a consequence of finely tuned physiological adaptations that partition the populations along physical and chemical gradients in the ecosystem. The correlation between evolutionary descent and temporal/spatial patterns we describe, confirmed that a minimum of three SAR11 ecotypes occupy the Sargasso Sea surface layer, and revealed new details of their population dynamics.

show abstract

“…As would be expected from a low percentage of unique genes in the SAGs, much of the metabolism of these organisms appeared to be similar to that of the surface strains, particularly the subclade Ia organisms. Collectively, the Ic subclades were predicted to be obligate aerobic organisms, with cytochrome c oxidase as the sole predicted terminal reductatse, a complete tricarboxylic acid cycle, conserved lesions in several glycolytic pathways (Schwalbach et al, 2010), a reliance on reduced sulfur compounds (Tripp et al, 2008) and pathways for the metabolism and oxidation of small organic molecules such as amino/carboxylic acids and one-carbon and methylated compounds (Yilmaz et al, 2011;Grote et al, 2012;Carini et al, 2012;Supplementary Table S1).…”

Section: Subclade Ic Relative Abundance In Metagenomic Datasetsmentioning

confidence: 99%

Single-cell enabled comparative genomics of a deep ocean SAR11 bathytype

et al. 2014

View full text Add to dashboard Cite

Bacterioplankton of the SAR11 clade are the most abundant microorganisms in marine systems, usually representing 25% or more of the total bacterial cells in seawater worldwide. SAR11 is divided into subclades with distinct spatiotemporal distributions (ecotypes), some of which appear to be specific to deep water. Here we examine the genomic basis for deep ocean distribution of one SAR11 bathytype (depth-specific ecotype), subclade Ic. Four single-cell Ic genomes, with estimated completeness of 55%-86%, were isolated from 770 m at station ALOHA and compared with eight SAR11 surface genomes and metagenomic datasets. Subclade Ic genomes dominated metagenomic fragment recruitment below the euphotic zone. They had similar COG distributions, high local synteny and shared a large number (69%) of orthologous clusters with SAR11 surface genomes, yet were distinct at the 16S rRNA gene and amino-acid level, and formed a separate, monophyletic group in phylogenetic trees. Subclade Ic genomes were enriched in genes associated with membrane/cell wall/envelope biosynthesis and showed evidence of unique phage defenses. The majority of subclade Ic-specfic genes were hypothetical, and some were highly abundant in deep ocean metagenomic data, potentially masking mechanisms for niche differentiation. However, the evidence suggests these organisms have a similar metabolism to their surface counterparts, and that subclade Ic adaptations to the deep ocean do not involve large variations in gene content, but rather more subtle differences previously observed deep ocean genomic data, like preferential amino-acid substitutions, larger coding regions among SAR11 clade orthologs, larger intergenic regions and larger estimated average genome size.

show abstract

SAR11 marine bacteria require exogenous reduced sulphur for growth

Cited by 347 publications

References 29 publications

Transcriptomic analysis of a marine bacterial community enriched with dimethylsulfoniopropionate

Transcriptomic analysis of a marine bacterial community enriched with dimethylsulfoniopropionate

Seasonal dynamics of SAR11 populations in the euphotic and mesopelagic zones of the northwestern Sargasso Sea

Single-cell enabled comparative genomics of a deep ocean SAR11 bathytype

Contact Info

Product

Resources

About