SO42–/HSO3 CO2/glucose H+/H2 CO2/methanol NAD+/NADH CO2/acetate S0/H2S CO2/CH4 FAD/FADH Pyruvate/lactate SO32–/H2S Adenosinephosphosulfate/AMP+HSO3– Fumarate/succinate Cytochromebox/red Ubiquinoneox/red DMSO/DMS Fe3+/Fe2+ Cytochromecox/red Chlorobenzoate–/benzoate NO2–/NO Cytochrome a ox/red NO3–/NO2– SeO42–/SeO32– NO3–/12N2 Mn4+/Mn2+ O2/H2O