metilotrófica

Metilotrófica describes a biological group of organisms that derive carbon and energy from one‑carbon (C1) compounds, primarily methanol, formaldehyde, methylamine or methane. The term stems from the Greek *methyl* (meth-) and the Latin suffix *-trophic* (feeding). These microorganisms include bacteria, archaea and a few unicellular eukaryotes that possess specialized enzymes to oxidise and assimilate C1 substrates.

There are two main categories. Obligate metilotróficas cannot grow on multi‑carbon compounds and rely entirely on C1 sources for both carbon skeletons and reducing power. Facultative species can switch between C1 and conventional sugars, adjusting their metabolism according to substrate availability. Key examples of obligates are the marine bacterium *Methylobacterium extorquens* and the archaeon *Methanobacterium* spp., whereas *Pseudomonas putida* and *Hyphomicrobium* spp. are common facultative metilotróficas.

The assimilation pathways differ among groups. The ribulose monophosphate (RuMP) cycle, used by *Methylobacterium*, condenses formaldehyde with ribulose‑5‑phosphate to form hexoses. The serine pathway, typical of many methylotrophic bacteria, converts formaldehyde to glycine and then to serine, which enters central metabolism. Methanogens oxidise methane to CO₂ via the methanogenesis pathway, capturing energy in the form of methyl group transfer reactions that generate ATP and reduced coenzymes.

Ecologically, metilotróficas play a crucial role in the global carbon cycle. They convert volatile C1 compounds emitted from plants and the ocean into biomass and eventually to CO₂, acting as natural filters that reduce greenhouse gas emissions. In industrial settings, engineered metilotróficas are exploited for bioconversions: production of single‑cell proteins, bioplastics, and bioremediation of methanol spills. Current research focuses on metabolic engineering to enhance yield, expand substrate ranges, and develop sustainable bioprocesses for commodity chemicals.