| gracilibacillus | 9 | genus | bacteria | | 74385 |
| gordonibacter | 1 | genus | bacteria | | 644652 |
| goodfellowiella | 2 | genus | bacteria | | 334857 |
| goniodes colchici | 2 | species | invertebrates | | 915406 |
| goniocotes chrysocephalus | 1 | species | invertebrates | | 915405 |
| gongylonema verrucosum | 1 | species | | helminths | |
| gongylonema sumani | -3 | species | | helminths | |
| gongylonema monnigi | -3 | species | | helminths | |
| gongylonema ingluvicola | 5 | species | | helminths | |
| gongylonema crami | -3 | species | | helminths | |
| glycomyces | 8 | genus | bacteria | | 58113 |
| gluconacetobacter | 29 | genus | bacteria | | 89583 |
| gloeotrichia | 16 | genus | bacteria | | 92939 |
| gloeothece | 22 | genus | bacteria | | 28070 |
| gloeocapsa | 26 | genus | bacteria | | 102231 |
| gloeobacter | 21 | genus | bacteria | | 33071 |
| glaciibacter | 1 | genus | bacteria | | 501022 |
| glaciecola | 12 | genus | bacteria | | 89404 |
| gilvibacter | 1 | genus | bacteria | | 379070 |
| gillisia | 5 | genus | bacteria | | 244698 |
| giesbergeria | 1 | genus | bacteria | | 352449 |
| geovibrio | 5 | genus | bacteria | | 46200 |
| geotoga | 1 | genus | bacteria | | 28233 |
| geothrix | 18 | genus | bacteria | | 44675 |
| geothermobacterium | 2 | genus | bacteria | | 169299 |
| geothermobacter | 3 | genus | bacteria | | 213223 |
| geosporobacter | 2 | genus | bacteria | | 390805 |
| georgenia | 4 | genus | bacteria | | 154116 |
| geopsychrobacter | 1 | genus | bacteria | | 271087 |
| geoglobus | 4 | genus | bacteria | | 190818 |
| geogemma | -3 | genus | bacteria | | 383690 |
| geobacter | 75 | genus | bacteria | | 28231 |
| geobacillus | 27 | genus | bacteria | | 129337 |
| geoalkalibacter | 2 | genus | bacteria | | 392332 |
| gemmatimonas | 5 | genus | bacteria | | 173479 |
| gemmata | 24 | genus | bacteria | | 113 |
| geminicoccus | 1 | genus | bacteria | | 489140 |
| gemella haemolysans | 15 | species | bacteria | bacteria | 1379 |
| gelria | 4 | genus | bacteria | | 189326 |
| gelidibacter | 10 | genus | bacteria | | 49279 |
| geitlerinema | 11 | genus | bacteria | | 63132 |
| gastrodiscus aegyptiacus | 3 | species | | helminths | |
| garciella | 3 | genus | bacteria | | 218204 |
| gallionella | 30 | genus | bacteria | | 96 |
| gallicola | 5 | genus | bacteria | | 162290 |
| gaetbulibacter | 4 | genus | bacteria | | 311207 |
| fusibacter | 2 | genus | bacteria | | 76008 |
| fusarium polyphialidicum | 4 | species | plants | fungi | 44410 |
| fusarium cf. solani hpf3 | -3 | species | plants | fungi | 765550 |
| furvibacter | -3 | genus | bacteria | | 404998 |
| fulvivirga | 1 | genus | bacteria | | 396811 |
| fulvimonas | 7 | genus | bacteria | | 155196 |
| fulvimarina | 4 | genus | bacteria | | 217510 |
| fulvibacter | 1 | genus | bacteria | | 426598 |
| fucophilus | 2 | genus | bacteria | | 177411 |
| fructobacillus | 2 | genus | bacteria | | 559173 |
| frondihabitans | 5 | genus | bacteria | | 447237 |
| frigoribacterium | 6 | genus | bacteria | | 96492 |
| friedmanniella | 9 | genus | bacteria | | 53387 |
| freyana anatina | 1 | species | invertebrates | | 61600 |
| frateuria | 15 | genus | bacteria | | 70411 |
| frankia | 53 | genus | bacteria | | 1854 |
| formosa | 58 | genus | bacteria | | 225842 |
| formivibrio | 5 | genus | bacteria | | 83764 |
| fodinicola | 1 | genus | bacteria | | 435913 |
| fluviicola | 2 | genus | bacteria | | 332102 |
| flexithrix | 6 | genus | bacteria | | 70992 |
| flexistipes | 7 | genus | bacteria | | 2351 |
| flectobacillus | 19 | genus | bacteria | | 101 |
| flavococcus | -3 | genus | bacteria | | 263574 |
| flavisolibacter | 2 | genus | bacteria | | 398041 |
| flaviramulus | 1 | genus | bacteria | | 369400 |
| flammeovirga | 3 | genus | bacteria | | 59739 |
| flagellimonas | 2 | genus | bacteria | | 444459 |
| fischerella | 23 | genus | bacteria | | 1190 |
| filomicrobium | 6 | genus | bacteria | | 119044 |
| filobacillus | 6 | genus | bacteria | | 160794 |
| filimonas | 1 | genus | bacteria | | 649460 |
| filibacter | 3 | genus | bacteria | | 34100 |
| filaroides hirthi | 10 | species | | helminths | |
| fibrobacter | 44 | genus | bacteria | | 832 |
| fervidococcus | 1 | | | | |
| fervidobacterium | 19 | genus | bacteria | | 2422 |
| fervidicola | 1 | genus | bacteria | | 555078 |
| ferrovum | 4 | genus | bacteria | | 416212 |
| ferroplasma | 22 | genus | bacteria | | 74968 |
| ferroglobus | 7 | genus | bacteria | | 54260 |
| ferritrophicum | 1 | genus | bacteria | | 370406 |
| ferrithrix | 1 | genus | bacteria | | 643949 |
| ferrimonas | 4 | genus | bacteria | | 44011 |
| ferrimicrobium | 6 | genus | bacteria | | 121038 |
| ferribacterium | 4 | genus | bacteria | | 88875 |
| fastidiosipila | 1 | genus | bacteria | | 236752 |
| fangia | 1 | genus | bacteria | | 482136 |
| fabibacter | 2 | genus | bacteria | | 446458 |
| exilispira | 1 | genus | bacteria | | 568400 |
| eupenidiella venezuelensis | -3 | species | plants | fungi | 1431930 |
| euhalothece | 8 | genus | bacteria | | 65097 |
| eudoraea | 10 | genus | bacteria | | 446680 |
| eudiplodinium maggii | 11 | species | invertebrates | protozoa | 47892 |