Facultative methanotrophs – diversity, genetics, molecular ecology and biotechnological potential: a mini-review

Abstract

Methane-oxidizing bacteria (methanotrophs) play a vital role in reducing atmospheric methane emissions, and hence mitigating their potent global warming effects. A significant proportion of the methane released is thermogenic natural gas, containing associated short-chain alkanes as well as methane. It was one hundred years following the description of methanotrophs that facultative strains were discovered and validly described. These can use some multi-carbon compounds in addition to methane, often small organic acids, such as acetate, or ethanol, although Methylocella strains can also use short-chain alkanes, presumably deriving a competitive advantage from this metabolic versatility. Here, we review the diversity and molecular ecology of facultative methanotrophs. We discuss the genetic potential of the known strains and outline the consequent benefits they may obtain. Finally, we review the biotechnological promise of these fascinating microbes.

Redox Zone and Trophic State as Drivers of Methane-Oxidizing Bacterial Abundance and Community Structure in Lake Sediments

“…Future research will reveal whether members of Methylocystis are involved in methane oxidation, e.g. coupled to metal reduction, as was previously shown for members of Methylosinus, a sister genus of Methylocystis (Zheng et al, 2020), or even subside on substrates other than methane, such as acetate or ethanol as was previously shown for (however aerobic) members of this genus (Haque et al, 2020;Oshkin et al, 2020).…”

Methanotrophs: Discoveries, Environmental Relevance, and a Perspective on Current and Future Applications

“…Strikingly, Verrucomicrobial methanotrophs and specific proteobacterial methanotrophs (e.g., Methylocella) rely on lanthanide metals for the second step of methanol oxidation as the catalytic driving force in MDHs from the XoxF family (Pol et al, 2014;Farhan Ul Haque et al, 2019;Smith and Wrighton, 2019). For a detailed review on the diversity of sDIMO methanotrophs, see Farhan Ul Haque et al (2020).…”

Crucial Role of the Chaperonin GroES/EL for Heterologous Production of the Soluble Methane Monooxygenase from Methylomonas methanica MC09

“…[12,14,15] Many genomes of methanotrophs have been sequenced in recent years, and many uncharacterized sMMOs have been identified in γ-proteobacteria and α-proteobacteria. [16] In particular, halotolerant sMMOs may have interesting features in terms of activity, reaction conditions and stability for biotechnological applications.…”