''Candidatus "''Methylomirabilis oxyfera" is a
candidate
A candidate, or nominee, is the prospective recipient of an award or honor, or a person seeking or being considered for some kind of position; for example:
* to be elected to an office — in this case a candidate selection procedure occurs.
* t ...
species of
Gram-negative bacteria belonging to the
NC10 phylum, characterized for its capacity to couple
anaerobic methane oxidation
Anaerobic means "living, active, occurring, or existing in the absence of free oxygen", as opposed to aerobic which means "living, active, or occurring only in the presence of oxygen." Anaerobic may also refer to:
* Anaerobic adhesive, a bonding a ...
with nitrite reduction in
anoxic
The term anoxia means a total depletion in the level of oxygen, an extreme form of hypoxia or "low oxygen". The terms anoxia and hypoxia are used in various contexts:
* Anoxic waters, sea water, fresh water or groundwater that are depleted of diss ...
environments.
To acquire oxygen for methane oxidation, ''M. oxyfera'' utilizes an intra-aerobic pathway through the reduction of nitrite (NO
2) to dinitrogen (N
2) and oxygen.
Enrichment
Enriched ''Ca. "M. oxyfera"'' cells have been identified as primarily having a unique polygonal cell shape through the use of electron microscopy techniques. Unlike
methanotroph
Methanotrophs (sometimes called methanophiles) are prokaryotes that metabolize methane as their source of carbon and chemical energy. They are bacteria or archaea, can grow aerobically or anaerobically, and require single-carbon compounds to su ...
ic
Pseudomonadota
Pseudomonadota (synonym Proteobacteria) is a major phylum of Gram-negative bacteria. The renaming of phyla in 2021 remains controversial among microbiologists, many of whom continue to use the earlier names of long standing in the literature. The ...
, ''Ca. "M. oxyfera"'' cells lack intracytoplasmic membranes when grown under laboratory conditions.
The optimum growth ranges for ''Ca. "M. oxyfera"'' is between pH 7-8 and 25-30 °C.
''Ca. "M. oxyfera"''cell envelopes are Gram-negative and are generally 0.25–0.5 μm in diameter and 0.8–1.1 μm in length.
Methane oxidation
''Ca. "M. oxyfera"'' has the capacity to
disproportionate
In chemistry, disproportionation, sometimes called dismutation, is a redox reaction in which one compound of intermediate oxidation state converts to two compounds, one of higher and one of lower oxidation states. More generally, the term can ...
nitric oxide into oxygen and nitrogen gas. This intermediate oxygen is then used in the oxidation of methane into carbon dioxide.
Overall reactions
Nitrogen oxide dismutation:
:
Methane oxidation:
:
Environmental significance
''Ca. "M. oxyfera"'' has been identified in several environments including rice paddy soil in China, multiple river and lake sediments,
and wastewater sludge in The Netherlands.
''Ca. "M. oxyfera"'' is predicted to inhabit environments with high concentrations of nitrogen and methane, near boundaries that separate oxic and anoxic zones. It is suggested that ''Ca. "M. oxyfera"'' and similar organisms contribute to the global carbon and nitrogen cycles. These organisms may also play a role in reducing the nutrient loads within freshwater ecosystems that have been contaminated with fertilizers.
See also
*
List of bacterial orders
This article lists the orders of the Bacteria. The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI)
and the phylogeny is based on 16S ...
*
List of bacteria genera This article lists the genera of the bacteria. The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI). However many taxonomic names are ...
References
{{Bacteria classification, state=collapsed
Gram-negative bacteria
Candidatus taxa