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Table 1 Metabolic reactions for chemolithoautotrophy considered in this study

From: Theoretical constraints of physical and chemical properties of hydrothermal fluids on variations in chemolithotrophic microbial communities in seafloor hydrothermal systems

Energy metabolism Overall chemical reaction Identified (I)/cultured (C) ΔG r° 2, 250(kJ) a
Aerobic reactions    
  Aerobic methanotrophy CH4 + 2O2 = CO2 + 2H2O I and C -860.7
  Hydrogenotrophic O2 reduction H2 + 1/2O2 = H2O I and C -264.4
  Thiotrophic (H2S-oxidizing) O2 reduction H2S + 2O2 = SO4 2- + 2H+ I and C -758.2
  Fe(II)-oxidizing O2 reduction Fe2+ + 1/4O2 + H+ = Fe3+ + 1/2H2O I and C -52.6
Anaerobic reactions    
  Hydrogenotrophic methanogenesis H2 + 1/4CO2 = 1/4CH4 + 1/2H2O I and C -49.2
  Hydrogenotrophic SO4 reduction H2 + 1/4SO4 2- + 1/2H+ = 1/4H2S + H2O I and C -74.9
  Hydrogenotrophic Fe(III) reduction H2 + 2Fe3+ = 2Fe2+ + 2H+ I and C -159.2
  Anoxic methanotrophy with SO4 reduction CH4 + SO4 2- = HCO3 - + HS- + H2O I but not yet C -30.1
  1. aStandard-state Gibbs free energy of the metabolic reactions at 2°C, 250 bar.