Methanotroph
Their habitats include wetlands, soils, marshes, rice paddies, landfills, aquatic systems (lakes, oceans, streams) and more.
The only facultative methanotrophs isolated to date are members of the genus Methylocella silvestris,[3][4] Methylocapsa aurea[5] and several Methylocystis strains.
[7][8][9] Generally, Type I methanotrophs tend to dominate in cold, anaerobic environments, meaning there is limited oxygen availability, which often have high methane concentrations.
[10] Type II methanotrophs tend to be more tolerant of stress and dominate in methane limited environments and acidic pHs.
[9] This table helps illuminate that methanotrophs that favor extreme environments, like hydrothermal vents, tend to uptake methane via the Calvin-Benson-Bassham Cycle (CBB).
"Candidatus Methylomirabilis oxyfera" belongs to the phylum NC10 bacteria, and can catalyze nitrite reduction through an "intra-aerobic" pathway, in which internally produced oxygen is used to oxidise methane.
Some specific methanotrophs can reduce nitrate,[19] nitrite,[20] iron,[21] sulfate,[22] or manganese ions and couple that to methane oxidation without syntrophic partner.
The exact mechanism is still a topic of debate but the most widely accepted theory is that the archaea use the reversed methanogenesis pathway to produce carbon dioxide and another, unknown intermediate, which is then used by the sulfate-reducing bacteria to gain energy from the reduction of sulfate to hydrogen sulfide and water.
[26] In 2010 a new bacterium Candidatus Methylomirabilis oxyfera from the phylum NC10 was identified that can couple the anaerobic oxidation of methane to nitrite reduction without the need for a syntrophic partner.
In wastewater treatment plants, the application of a mix of methanotrophic bacteria has the potential to reduce costs and increase overall efficiency at removing nitrogen and byproducts.
[27] Depending upon environmental conditions, these methanotrophs can also produce biomolecules during the wastewater treatment process that are useful for a wide range of applications.
