Fig. 2

Genome cartoon of three representative candidate sulfate reducers. The cartoon displays metabolic pathways encoded by a Chloroflexi (orange), Desulfobacteraceae (yellow), and Nitrospiraceae (blue) genome. The abbreviations and chemical formulae are as follows: SO₄²⁻, sulfate; Sat, sulfate adenylyltransferase; APS, adenosine 5′-phosphosulfate; AprBA, APS reductase subunits A and B; SO₃²⁻, sulfite; DsrAB, dissimilatory sulfite reductase subunits A and B; PEP, phosphoenolpyruvate; PK, pyruvate orthophosphate dikinase, PW: pyruvate water dikinase; ADH, alcohol dehydrogenase; LDH, lactate dehydrogenase; PDH, pyruvate dehydrogenase; PFOR, pyruvate ferredoxin oxidoreductase; AFOR, acetaldehyde ferredoxin oxidoreductase; ALDH, aldehyde dehydrogenase; ACS, acetate synthetase; HCOO⁻, formate; FDH, formate dehydrogenase; CO₂, carbon dioxide; H₂, hydrogen; Hase, nickel-iron hydrogenase; H⁺, proton; NDH, NADH dehydrogenase; SDH, succinate dehydrogenase; cyt_bd, cytochrome bd; cyt_aa3, aa₃-type cytochrome; TCA, tricarboxylic acid cycle; N₂O, nitrous oxide; NosZ, nitrous oxide reductase; N₂, dinitrogen; NarGHI, nitrate reductase; NirBD, cytoplasmic, ammonia-forming nitrite reductase; NrfAH, membrane-bound, ammonia-forming nitrite reductase; NO₂⁻, nitrite; NH₃, ammonia