Limits...
Energy landscapes shape microbial communities in hydrothermal systems on the Arctic Mid-Ocean Ridge.

Dahle H, Økland I, Thorseth IH, Pederesen RB, Steen IH - ISME J (2015)

Bottom Line: Our models indicate that the sediment-influenced LCVF has a much higher potential for both anaerobic and aerobic methane oxidation, as well as aerobic ammonium and hydrogen oxidation, than the SMVF.The modelled energy landscapes were used to develop microbial community composition models, which were compared with community compositions in environmental samples inside or on the exterior of hydrothermal chimneys, as assessed by pyrosequencing of partial 16S rRNA genes.We show that modelled microbial communities based solely on thermodynamic considerations can have a high predictive power and provide a framework for analyses of the link between energy availability and microbial community composition.

View Article: PubMed Central - PubMed

Affiliation: 1] Centre for Geobiology, University of Bergen, Bergen, Norway [2] Department of Biology, University of Bergen, Bergen, Norway.

ABSTRACT
Methods developed in geochemical modelling combined with recent advances in molecular microbial ecology provide new opportunities to explore how microbial communities are shaped by their chemical surroundings. Here, we present a framework for analyses of how chemical energy availability shape chemotrophic microbial communities in hydrothermal systems through an investigation of two geochemically different basalt-hosted hydrothermal systems on the Arctic Mid-Ocean Ridge: the Soria Moria Vent field (SMVF) and the Loki's Castle Vent Field (LCVF). Chemical energy landscapes were evaluated through modelling of the Gibbs energy from selected redox reactions under different mixing ratios between seawater and hydrothermal fluids. Our models indicate that the sediment-influenced LCVF has a much higher potential for both anaerobic and aerobic methane oxidation, as well as aerobic ammonium and hydrogen oxidation, than the SMVF. The modelled energy landscapes were used to develop microbial community composition models, which were compared with community compositions in environmental samples inside or on the exterior of hydrothermal chimneys, as assessed by pyrosequencing of partial 16S rRNA genes. We show that modelled microbial communities based solely on thermodynamic considerations can have a high predictive power and provide a framework for analyses of the link between energy availability and microbial community composition.

No MeSH data available.


Related in: MedlinePlus

Phylum- to class-level taxonomic assignments of 16S rRNA gene reads obtained from LCVF biofilms (ROV3, ROV4, ROV9), and flange and chimney samples from the SMVF (F1–4 and W1). Replicates are indicated with letters ‘a' and ‘b'.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4478700&req=5

fig6: Phylum- to class-level taxonomic assignments of 16S rRNA gene reads obtained from LCVF biofilms (ROV3, ROV4, ROV9), and flange and chimney samples from the SMVF (F1–4 and W1). Replicates are indicated with letters ‘a' and ‘b'.

Mentions: Epsilonproteobacteria dominated in the ROV3 and ROV4 samples (Figure 6). The three most dominant Epsilonproteobacteria OTUs from ROV3, representing 94% of the Epsilonproteobacteria in this sample, were similar (94–95%) to Sulfurovum lithotrophicum (accession number AB091292). The three most dominant Epsilonproteobacteria OTUs from ROV4, representing 65% of the Epsilonproteobacteria, were similar (95–100%) to Sulfurimonas denitrificans (accession number L40808) or Sulfurimonas autotrophica (accession number AB088431). Cultured members of Epsilonproteobacteria detected in hydrothermal systems are microaerophilic sulphur oxidizers with a versatile metabolism including the ability to use various sulphur compounds and hydrogen as electron donors, and oxygen and nitrate as the electron acceptor (Campbell et al., 2006). Gammaproteobacteria of the Methylococcales order dominated in ROV9 (Figure 6 and Supplementary Figure 1). Within this group, 87% of the sequences clustered in an OTU that was 100% similar to endosymbiotic methane oxidizers from the Logachev vent field (accession number AM083965) (Duperron et al., 2006), whereas 12% clustered in a OTU that was 96% similar to the methanotrophic Methylomarinum vadi (accession number AB301717) (Hirayama et al., 2013). Epsilonproteobacteria were also detected here with an abundance of 9–11% (Figure 6), and members of this group were similar to the ROV3 and ROV4 samples, mostly assigned to the Sulfurovum and Sulfurimonas genera (Supplementary Figure 1).


Energy landscapes shape microbial communities in hydrothermal systems on the Arctic Mid-Ocean Ridge.

Dahle H, Økland I, Thorseth IH, Pederesen RB, Steen IH - ISME J (2015)

Phylum- to class-level taxonomic assignments of 16S rRNA gene reads obtained from LCVF biofilms (ROV3, ROV4, ROV9), and flange and chimney samples from the SMVF (F1–4 and W1). Replicates are indicated with letters ‘a' and ‘b'.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4478700&req=5

fig6: Phylum- to class-level taxonomic assignments of 16S rRNA gene reads obtained from LCVF biofilms (ROV3, ROV4, ROV9), and flange and chimney samples from the SMVF (F1–4 and W1). Replicates are indicated with letters ‘a' and ‘b'.
Mentions: Epsilonproteobacteria dominated in the ROV3 and ROV4 samples (Figure 6). The three most dominant Epsilonproteobacteria OTUs from ROV3, representing 94% of the Epsilonproteobacteria in this sample, were similar (94–95%) to Sulfurovum lithotrophicum (accession number AB091292). The three most dominant Epsilonproteobacteria OTUs from ROV4, representing 65% of the Epsilonproteobacteria, were similar (95–100%) to Sulfurimonas denitrificans (accession number L40808) or Sulfurimonas autotrophica (accession number AB088431). Cultured members of Epsilonproteobacteria detected in hydrothermal systems are microaerophilic sulphur oxidizers with a versatile metabolism including the ability to use various sulphur compounds and hydrogen as electron donors, and oxygen and nitrate as the electron acceptor (Campbell et al., 2006). Gammaproteobacteria of the Methylococcales order dominated in ROV9 (Figure 6 and Supplementary Figure 1). Within this group, 87% of the sequences clustered in an OTU that was 100% similar to endosymbiotic methane oxidizers from the Logachev vent field (accession number AM083965) (Duperron et al., 2006), whereas 12% clustered in a OTU that was 96% similar to the methanotrophic Methylomarinum vadi (accession number AB301717) (Hirayama et al., 2013). Epsilonproteobacteria were also detected here with an abundance of 9–11% (Figure 6), and members of this group were similar to the ROV3 and ROV4 samples, mostly assigned to the Sulfurovum and Sulfurimonas genera (Supplementary Figure 1).

Bottom Line: Our models indicate that the sediment-influenced LCVF has a much higher potential for both anaerobic and aerobic methane oxidation, as well as aerobic ammonium and hydrogen oxidation, than the SMVF.The modelled energy landscapes were used to develop microbial community composition models, which were compared with community compositions in environmental samples inside or on the exterior of hydrothermal chimneys, as assessed by pyrosequencing of partial 16S rRNA genes.We show that modelled microbial communities based solely on thermodynamic considerations can have a high predictive power and provide a framework for analyses of the link between energy availability and microbial community composition.

View Article: PubMed Central - PubMed

Affiliation: 1] Centre for Geobiology, University of Bergen, Bergen, Norway [2] Department of Biology, University of Bergen, Bergen, Norway.

ABSTRACT
Methods developed in geochemical modelling combined with recent advances in molecular microbial ecology provide new opportunities to explore how microbial communities are shaped by their chemical surroundings. Here, we present a framework for analyses of how chemical energy availability shape chemotrophic microbial communities in hydrothermal systems through an investigation of two geochemically different basalt-hosted hydrothermal systems on the Arctic Mid-Ocean Ridge: the Soria Moria Vent field (SMVF) and the Loki's Castle Vent Field (LCVF). Chemical energy landscapes were evaluated through modelling of the Gibbs energy from selected redox reactions under different mixing ratios between seawater and hydrothermal fluids. Our models indicate that the sediment-influenced LCVF has a much higher potential for both anaerobic and aerobic methane oxidation, as well as aerobic ammonium and hydrogen oxidation, than the SMVF. The modelled energy landscapes were used to develop microbial community composition models, which were compared with community compositions in environmental samples inside or on the exterior of hydrothermal chimneys, as assessed by pyrosequencing of partial 16S rRNA genes. We show that modelled microbial communities based solely on thermodynamic considerations can have a high predictive power and provide a framework for analyses of the link between energy availability and microbial community composition.

No MeSH data available.


Related in: MedlinePlus