Methanothrix
From Wikipedia, the free encyclopedia
| Methanothrix | |
|---|---|
Scientific classification  | |
| Domain: | Archaea |
| Kingdom: | Methanobacteriati |
| Phylum: | Methanobacteriota |
| Class: | "Methanomicrobia" |
| Order: | Methanosarcinales |
| Family: | Methanosaetaceae |
| Genus: | Methanothrix Huser, Wuhrmann & Zehnder 1983 nom. nov. |
| Type species | |
| Methanothrix soehngenii Huser, Wuhrmann & Zehnder 1983 | |
| Species | |
| |
| Synonyms | |
| |
Methanothrix is a genus of methanogenic archaea within the phylum Methanobacteriota.[1][2] Methanothrix cells were first isolated from a mesophilic sewage digester but have since been found in many anaerobic and aerobic environments.[3][4] Methanothrix were originally understood to be obligate anaerobes that can survive exposure to high concentrations of oxygen,[5][6] but recent studies have shown at least one Candidatus operational taxonomic unit proposed to be in the Methanothrix genus not only survives but remains active in oxic soils.[4] This proposed species, Ca. Methanothrix paradoxum, is frequently found in methane-releasing ecosystems and is the dominant methanogen in oxic soils.
Methanothrix are non-motile rod-shaped cells which connect together to form long filaments.[5][7] These filaments are enclosed in a proteinaceous sheath.[6] Methanothrix species, like their close relative Methanosarcina barkeri, have membranes entirely composed of diphytanylglycerol diethers.[6][8][9]
| 16S rRNA based LTP_06_2022[10][11][12] | 53 marker proteins based GTDB 10-RS226[13][14][15] | ||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
|
Metabolism
Methanothrix species use acetate[16][17] and carbon dioxide[3][18] as carbon substrates.
When using acetate, Methanothrix species use an incomplete citric acid cycle in the oxidative direction.[6][8] After formation of acetyl-CoA, the carbon-carbon bond of acetate is cleaved by a carbon monoxide dehydrogenase/acetyl-CoA synthase enzyme. The methyl moiety is transferred through multiple complexes until it is finally reduced to methane by a methyl-CoM reductase.[17]
Methanothrix species have been observed receiving electrons to reduce carbon dioxide to methane through direct interspecies electron transfer (DIET) with Geobacter species.[3][18][19] Geobacter sulfurreducens transfers electrons into Methanothrix cells using electrically conductive pili.[20]