| Orth | Species | Gene | Name | Description | Fitness | %Id | Cov |
| | Azospirillum sp. SherDot2 | MPMX19_05288 | | Uptake hydrogenase small subunit | insig. | 100 | 100 |
| o | Xanthobacter sp. DMC5 | GFF4444 | | Uptake hydrogenase small subunit | insig. | 90 | 98 |
| o | Variovorax sp. OAS795 | ABID97_RS13685 | | hydrogenase small subunit | insig. | 89 | 90 |
| o | Hydrogenophaga sp. GW460-11-11-14-LB1 | GFF2230 | | Uptake hydrogenase small subunit precursor (EC 1.12.99.6) | insig. | 85 | 91 |
| o | Rhodopseudomonas palustris CGA009 | TX73_004955 | | hydrogenase small subunit | insig. | 75 | 100 |
| o | Salmonella enterica subsp. enterica serovar Typhimurium str. MS1868 | GFF2787 | | Uptake hydrogenase small subunit precursor (EC 1.12.99.6) | insig. | 68 | 99 |
| o | Rhodospirillum rubrum S1H | Rru_A1161 | | Ni-Fe hydrogenase, small subunit (NCBI) | insig. | 76 | 91 |
| o | Escherichia coli ECOR27 | NOLOHH_21715 | hyaA | hydrogenase 1 small subunit | insig. | 69 | 93 |
| o | Escherichia coli ECOR38 | HEPCGN_23360 | hyaA | hydrogenase 1 small subunit | insig. | 69 | 93 |
| o | Escherichia coli BL21 | ECD_00975 | | hydrogenase 1, small subunit | insig. | 69 | 93 |
| o | Escherichia fergusonii Becca | EFB2_03099 | | Hydrogenase-1 small chain | insig. | 69 | 93 |
| o | Escherichia coli ECRC62 | BNILDI_19880 | hyaA | hydrogenase 1 small subunit | insig. | 69 | 93 |
| o | Escherichia coli HS(pFamp)R (ATCC 700891) | OHPLBJKB_02694 | | Hydrogenase-1 small chain | insig. | 69 | 93 |
| o | Escherichia coli Nissle 1917 | ECOLIN_RS05110 | | hydrogenase 1 small subunit | insig. | 69 | 93 |
| o | Escherichia coli BW25113 | b0972 | hyaA | hydrogenase 1, small subunit (NCBI) | insig. | 69 | 93 |
| o | Escherichia coli ECRC100 | OKFHMN_04810 | hyaA | hydrogenase 1 small subunit | cofit | 69 | 93 |
| o | Escherichia coli ECRC101 | MCAODC_24195 | hyaA | hydrogenase 1 small subunit | insig. | 69 | 93 |
| o | Escherichia coli ECRC102 | NIAGMN_23040 | hyaA | hydrogenase 1 small subunit | insig. | 69 | 93 |
| o | Escherichia coli ECRC98 | JDDGAC_08420 | hyaA | hydrogenase 1 small subunit | insig. | 69 | 93 |
| o | Escherichia coli ECRC99 | KEDOAH_22935 | hyaA | hydrogenase 1 small subunit | no data | 69 | 93 |
| | Salmonella enterica subsp. enterica serovar Typhimurium str. MS1868 | GFF2525 | | Uptake hydrogenase small subunit precursor (EC 1.12.99.6) | insig. | 74 | 90 |
| o | Alteromonas macleodii MIT1002 | MIT1002_00274 | | Uptake hydrogenase small subunit precursor | insig. | 49 | 86 |
| o | Shewanella amazonensis SB2B | Sama_1679 | | hydrogen:quinone oxidoreductase (RefSeq) | sig. | 46 | 97 |
| o | Shewanella sp. ANA-3 | Shewana3_1880 | | hydrogenase (NiFe) small subunit HydA (RefSeq) | insig. | 46 | 97 |
| o | Shewanella oneidensis MR-1 | SO2099 | hoxK | quinone-reactive Ni/Fe hydrogenase, small subunit precursor (NCBI ptt file) | sig. | 45 | 97 |
| o | Shewanella loihica PV-4 | Shew_1765 | | hydrogenase (NiFe) small subunit HydA (RefSeq) | insig. | 44 | 97 |
| o | Magnetospirillum magneticum AMB-1 | AMB_RS08350 | | hydrogenase 2 small subunit | insig. | 40 | 99 |
| | Azospirillum brasilense Sp245 | AZOBR_RS20405 | | hydrogenase 2 small subunit | insig. | 44 | 80 |
| o | Dechlorosoma suillum PS | Dsui_3012 | | hydrogenase (NiFe) small subunit HydA | no data | 45 | 83 |
| | Escherichia coli BL21 | ECD_02873 | | hydrogenase 2, small subunit | cofit | 43 | 82 |
| | Escherichia fergusonii Becca | EFB2_00810 | | Hydrogenase-2 small chain | cofit | 43 | 82 |
| | Escherichia coli ECOR27 | NOLOHH_10780 | hybO | hydrogenase 2 small subunit | insig. | 43 | 82 |
| | Escherichia coli ECOR38 | HEPCGN_17865 | hybO | hydrogenase 2 small subunit | insig. | 43 | 82 |
| | Escherichia coli ECRC100 | OKFHMN_19005 | hybO | hydrogenase 2 small subunit | cofit | 43 | 82 |
| | Escherichia coli ECRC101 | MCAODC_09520 | hybO | hydrogenase 2 small subunit | insig. | 43 | 82 |
| | Escherichia coli ECRC102 | NIAGMN_16770 | hybO | hydrogenase 2 small subunit | insig. | 43 | 82 |
| | Escherichia coli ECRC62 | BNILDI_00735 | hybO | hydrogenase 2 small subunit | insig. | 43 | 82 |
| | Escherichia coli ECRC98 | JDDGAC_22640 | hybO | hydrogenase 2 small subunit | insig. | 43 | 82 |
| | Escherichia coli ECRC99 | KEDOAH_09140 | hybO | hydrogenase 2 small subunit | no data | 43 | 82 |
| | Escherichia coli HS(pFamp)R (ATCC 700891) | OHPLBJKB_00702 | | Hydrogenase-2 small chain | insig. | 43 | 82 |
| | Escherichia coli Nissle 1917 | ECOLIN_RS17265 | | hydrogenase 2 small subunit | insig. | 43 | 82 |
| | Escherichia coli BW25113 | b2997 | hybO | hydrogenase 2, small subunit (NCBI) | sig. | 43 | 82 |
| | Salmonella enterica subsp. enterica serovar Typhimurium str. MS1868 | GFF3108 | | Uptake hydrogenase small subunit precursor (EC 1.12.99.6) | insig. | 43 | 82 |
| o | Desulfovibrio vulgaris Miyazaki F | DvMF_0271 | | hydrogenase (NiFe) small subunit HydA (RefSeq) | insig. | 42 | 84 |
| | Dickeya dianthicola 67-19 | HGI48_RS14230 | | hydrogenase 2 small subunit | insig. | 41 | 82 |
| | Dickeya dianthicola ME23 | DZA65_RS14905 | | hydrogenase 2 small subunit | insig. | 41 | 82 |
| | Dickeya dadantii 3937 | DDA3937_RS14255 | | hydrogenase 2 small subunit | insig. | 41 | 82 |
| o | Desulfovibrio vulgaris Hildenborough JW710 | DVU2525 | hynB-2 | periplasmic [NiFe] hydrogenase, small subunit, isozyme 2 (TIGR) | insig. | 43 | 81 |
| | Desulfovibrio vulgaris Hildenborough JW710 | DVU1921 | hynB-1 | periplasmic [NiFe] hydrogenase, small subunit, isozyme 1 (TIGR) | insig. | 42 | 84 |
| | Desulfovibrio vulgaris Miyazaki F | DvMF_1732 | | hydrogenase (NiFe) small subunit HydA (RefSeq) | insig. | 42 | 87 |
| | Desulfovibrio vulgaris Hildenborough JW710 | DVU1917 | hysB | periplasmic [NiFeSe] hydrogenase, small subunit (TIGR) | strong | 36 | 82 |
| | Desulfovibrio vulgaris Miyazaki F | DvMF_0274 | | hydrogenase (NiFe) small subunit HydA (RefSeq) | cofit | 35 | 82 |
| | Variovorax sp. OAS795 | ABID97_RS13585 | | HupU protein | insig. | 27 | 73 |
| | Dechlorosoma suillum PS | Dsui_1153 | | Ni,Fe-hydrogenase I small subunit | insig. | 27 | 71 |
| | Magnetospirillum magneticum AMB-1 | AMB_RS09805 | | uptake hydrogenase | insig. | 26 | 70 |
| | Rhodopseudomonas palustris CGA009 | TX73_004945 | | HupU protein | insig. | 24 | 70 |
| | Xanthobacter sp. DMC5 | GFF2240 | | Periplasmic [NiFeSe] hydrogenase small subunit | insig. | 26 | 76 |
| | Magnetospirillum magneticum AMB-1 | AMB_RS05665 | | NADH ubiquinone oxidoreductase | insig. | 24 | 85 |
| | Hydrogenophaga sp. GW460-11-11-14-LB1 | GFF2209 | | Uptake hydrogenase small subunit precursor (EC 1.12.99.6) | insig. | 26 | 47 |
| | Azospirillum sp. SherDot2 | MPMX19_05299 | | Periplasmic [NiFeSe] hydrogenase small subunit | insig. | 25 | 73 |