Redox Couple n Eo' (mV) 2CO2 + 2acetate/hexose 8 −670 CO2 + acetate/pyruvate 2 −660 CO2 + acetate/lactate 4 −430 CO2/formate 2 −432 2H+/H2 2 −414 6CO2/hexose 24 −410 acetate/ethanol 4 −390 CO2/methanol 6 −370 4CO2/succinate 12 −312 7CO2/benzoate 30 −300 2CO2/acetate 8 −290 2acetate/butyrate 4 −290 CO2 + acetate/glycerol 6 −290 4CO2/butyrate 20 −280 3CO2/propionate 7 −280 6CO2/hexane 8 −250 CO2/CH4 8 −244 SO42-/HS- 8 −217 glycine/acetate+NH3 2 −10 fumarate/succinate 2 +33 NO2-/NH3 6 +330 NO3-/NH3 8 +360 NO3-/ NO2- 2 +430 2NO3-/N2 10 +760 O2/2H2O 4 +818 H2O2/2H2O 2 +1350

Table 1: Reduction potentials at pH 7, 25°C, 1 M solutes (1 bar gases) except H+ [8].