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

Modelled energy availability from 10 redox processes (see Table 3) as a function of temperature and SW:HF mixing ratios at the SMVF and the LCVF. Second axis indicates the energy released when reactants in a mixture of SW and 1 kg hydrothermal fluid react until equilibrium is reached. Numbers in the legend refer to numbered redox reations in Table 3. For clarity, energies from redox reactions with nitrate as the electron acceptor are indicated with dashed lines. Note that different redox processes are considered independently.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig4: Modelled energy availability from 10 redox processes (see Table 3) as a function of temperature and SW:HF mixing ratios at the SMVF and the LCVF. Second axis indicates the energy released when reactants in a mixture of SW and 1 kg hydrothermal fluid react until equilibrium is reached. Numbers in the legend refer to numbered redox reations in Table 3. For clarity, energies from redox reactions with nitrate as the electron acceptor are indicated with dashed lines. Note that different redox processes are considered independently.

Mentions: Gibbs energies from 10 chemical reactions or processes (Table 3) were modelled at different SW:HF mixing ratios at SMVF and LCVF. Our models consider maximum potential energies per kg of HF (Figure 4). Negative values of Gibbs energy indicate exergonic reactions acting as potential energy sources for microorganisms.


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)

Modelled energy availability from 10 redox processes (see Table 3) as a function of temperature and SW:HF mixing ratios at the SMVF and the LCVF. Second axis indicates the energy released when reactants in a mixture of SW and 1 kg hydrothermal fluid react until equilibrium is reached. Numbers in the legend refer to numbered redox reations in Table 3. For clarity, energies from redox reactions with nitrate as the electron acceptor are indicated with dashed lines. Note that different redox processes are considered independently.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig4: Modelled energy availability from 10 redox processes (see Table 3) as a function of temperature and SW:HF mixing ratios at the SMVF and the LCVF. Second axis indicates the energy released when reactants in a mixture of SW and 1 kg hydrothermal fluid react until equilibrium is reached. Numbers in the legend refer to numbered redox reations in Table 3. For clarity, energies from redox reactions with nitrate as the electron acceptor are indicated with dashed lines. Note that different redox processes are considered independently.
Mentions: Gibbs energies from 10 chemical reactions or processes (Table 3) were modelled at different SW:HF mixing ratios at SMVF and LCVF. Our models consider maximum potential energies per kg of HF (Figure 4). Negative values of Gibbs energy indicate exergonic reactions acting as potential energy sources for microorganisms.

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