| methanobrevibacter millerae | species | archaea | bacteria | species | 230361 |
| methanobrevibacter olleyae | species | archaea | bacteria | species | 294671 |
| methanobrevibacter ruminantium m1 | no rank | archaea | bacteria | no rank | 634498 |
| methanobrevibacter smithii | species | archaea | bacteria | species | 2173 |
| methanobrevibacter sp. | no rank | archaea | bacteria | species | 66852 |
| methanobrevibacter sp. cirg-gmbb01 | no rank | archaea | bacteria | species | 645278 |
| methanobrevibacter sp. cirg-gmbb02 | no rank | archaea | bacteria | species | 645279 |
| methanobrevibacter thaueri | species | archaea | bacteria | species | 190975 |