Table 1.
Features of the three ANME groups
| ANME-1 | ANME-2 | ANME-3 | |
|---|---|---|---|
| Common features | |||
| Habitat | Various anaerobic areas (marine sediments, cold seep, lake sediments, soils, oil field sediments, etc.) | Various anaerobic areas (marine sediments, cold seep, lake sediments, soils, oil field sediments, etc.) | Submarine mud volcanoes and marine methane seep |
| Subgroup | a, b | a, b, c, d | ND |
| Pure culture | No | No | No |
| Features associated with SRB | |||
| Associated SRB | Desulfosarcina and Desulfococcus | Desulfosarcina and Desulfococcus | Desulfobulbus |
| Associated form | Often loose | Often form structured consortia | Often form structured consortia |
| Associated necessity | No | No | No |
| Single-cell form | Often | Yes | Yes |
| Features related to methanogens | |||
| Related methanogen | Methanosarcinales and Methanomicrobiales | Methanosarcinales | Methanococcoides |
| Shape | Often rod shaped (like Methanobacteriales and Methanomicrobiales) | Often coccoid shaped (like Methanosarcinales) | Often coccoid shaped (like Methanosarcinales) |
| Harbour mcrA | Yes | Yes | Yes |
| mcrA subgroup | a, b (identified) | c, d (identified) | f (identified) |
| e (possible) | |||
| Produce methane | Yes | ND | ND |
| Autofluorescent under UV light (like methanogens) | Yes | Yes | Yes |
ANME, anaerobic methanotrophic archaea; ND, not determined; SRB, sulfate-reducing bacteria.