Methylomonas methanica is a species of Gram‑negative, aerobic methanotrophic bacteria belonging to the family Methylococcaceae within the order Methylococcales of the class Gammaproteobacteria. The organism is an obligate methane‑oxidizing bacterium (methanotroph) that utilizes methane as its sole carbon and energy source, employing the enzyme particulate methane mono‑oxygenase (pMMO) to catalyze the initial oxidation of methane to methanol.
Taxonomy
- Domain: Bacteria
- Phylum: Proteobacteria
- Class: Gammaproteobacteria
- Order: Methylococcales
- Family: Methylococcaceae
- Genus: Methylomonas
- Species: Methylomonas methanica
Morphology and Physiology
Cells are typically short rods or coccoid, measuring 1–2 µm in length. They are motile by means of a polar flagellum. The organism is obligately aerobic, requiring oxygen as the terminal electron acceptor for growth. In addition to methane, M. methanica can grow on methanol, which is produced intracellularly during methane oxidation. The bacterium possesses internal membrane systems enriched with pMMO, characteristic of Type I methanotrophs.
Ecology and Habitat
Methylomonas methanica has been isolated from a variety of aquatic and terrestrial environments where methane is present, including freshwater lakes, wetlands, and methane‑rich soils. Its presence contributes to the biological consumption of methane, thereby influencing global methane budgets and mitigating greenhouse gas emissions.
Type Strain
The type strain of M. methanica is designated as NCIMB 11130 (also catalogued as ATCC 33146). This strain serves as the reference for phenotypic and genotypic characterisation of the species.
Genomic Information
Whole‑genome sequences for the type strain have been deposited in public databases, revealing genes encoding the pMMO complex, methanol dehydrogenase, and pathways for formaldehyde assimilation via the ribulose‑monophosphate (RuMP) cycle, consistent with Type I methanotroph metabolism.
Significance
Methylomonas methanica is of interest in environmental microbiology and biotechnology. Its capacity for methane oxidation is studied for potential applications in biofiltration of methane emissions and the bioconversion of methane to value‑added products such as methanol and biopolymers.
References
(References to primary taxonomic descriptions, genome announcements, and ecological studies are available in peer‑reviewed literature; specific citations are omitted here for brevity.)
