| Role | Gene | Name | |
| Formate dehydrogenase -O, gamma subunit (EC 1.2.1.2) | SO3922 | | |
| | SO4511 | | |
| | SO4515 | | |
| Formate dehydrogenase N alpha subunit (EC 1.2.1.2) | No genes | | |
| Formate dehydrogenase N beta subunit (EC 1.2.1.2) | SO0102 | fdnH | |
| Formate dehydrogenase N gamma subunit (EC 1.2.1.2) | SO0103 | fdnI | |
| Formate dehydrogenase O alpha subunit (EC 1.2.1.2) | No genes | | |
| Formate dehydrogenase O beta subunit (EC 1.2.1.2) | No genes | | |
| Formate dehydrogenase O gamma subunit (EC 1.2.1.2) | No genes | | |
| Formate dehydrogenase O putative subunit | No genes | | |
| Formate dehydrogenase chain D (EC 1.2.1.2) | SO0107 | fdhD | |
| | SO4503 | | |
| Formate dehydrogenase putative subunit (EC 1.2.1.2) | No genes | | |
| Formate dehydrogenase related protein | No genes | | |
| Formate dehydrogenase-O, iron-sulfur subunit (EC 1.2.1.2) | No genes | | |
| Formate dehydrogenase-O, major subunit (EC 1.2.1.2) | SO0988 | | |
| | SO4509 | | |
| | SO4513 | | |
| Formate hydrogenlyase hypothetical subunit | No genes | | |
| Formate hydrogenlyase regulatory protein HycA | No genes | | |
| Formate hydrogenlyase subunit 2 | No genes | | |
| Formate hydrogenlyase subunit 3 | No genes | | |
| Formate hydrogenlyase subunit 3/Multisubunit Na+/H+ antiporter, MnhD subunit | No genes | | |
| Formate hydrogenlyase subunit 4 | No genes | | |
| Formate hydrogenlyase subunit 5 | No genes | | |
| Formate hydrogenlyase subunit 6 | No genes | | |
| Formate hydrogenlyase subunit 7 | No genes | | |
| Formate hydrogenlyase transcriptional activator | SO3059 | | |
| | SO3660 | | |
| Hydrogenase-4 component A (EC 1.-.-.-) | No genes | | |
| Hydrogenase-4 component B (EC 1.-.-.-) | No genes | | |
| Hydrogenase-4 component C (EC 1.-.-.-) | No genes | | |
| Hydrogenase-4 component D (EC 1.-.-.-) | No genes | | |
| Hydrogenase-4 component E (EC 1.-.-.-) | No genes | | |
| Hydrogenase-4 component F (EC 1.-.-.-) | No genes | | |
| Hydrogenase-4 component G (EC 1.-.-.-) | No genes | | |
| Hydrogenase-4 component H (EC 1.-.-.-) | No genes | | |
| Hydrogenase-4 component I (EC 1.-.-.-) | No genes | | |
| Hydrogenase-4 transcriptional activator | No genes | | |
| Hypothetical protein YrhD | No genes | | |
| Hypothetical protein probably related to Formate dehydrogenase function | SO4505 | | |
| NAD-dependent formate dehydrogenase (EC 1.2.1.2) | No genes | | |
| NAD-dependent formate dehydrogenase alpha subunit | No genes | | |
| NAD-dependent formate dehydrogenase beta subunit | No genes | | |
| NAD-dependent formate dehydrogenase delta subunit | No genes | | |
| NAD-dependent formate dehydrogenase gamma subunit | No genes | | |
| Putative formate dehydrogenase iron-sulfur subunit (EC 1.2.1.2) | No genes | | |
| Putative formate dehydrogenase oxidoreductase protein | No genes | | |
| Putative formate dehydrogenase, cytochrome B subunit (EC 1.2.1.2) | No genes | | |
| Putative formate dehydrogenase-specific chaperone | SO4507 | | |
| formate dehydrogenase formation protein FdhE | SO0104 | fdhE | |
| hydrogenase, HycC subunit, putative | No genes | | |
| hydrogenase, group 4, HycE subunit, putative | No genes | | |
| hydrogenase, group 4, HycG subunit, putative | No genes | | |
| tungsten-containing formate dehydrogenase alpha subunit | No genes | | |
| tungsten-containing formate dehydrogenase beta subunit | No genes | | |