Capturing methane with recombinant soluble methane monooxygenase and recombinant methyl-coenzyme M reductase

Abstract

Methane capture via oxidation is considered one of the 'Holy Grails' of catalysis (Tucci and Rosenzweig, 2024). Methane is also a primary greenhouse gas that has to be reduced by 1.2 billion metric tonnes in 10 years to decrease global warming by only 0.23°C (He and Lidstrom, 2024); hence, new technologies are needed to reduce atmospheric methane levels. In Nature, methane is captured aerobically by methanotrophs and anaerobically by anaerobic methanotrophic archaea; however, the anaerobic process dominates. Here, we describe the history and potential of using the two remarkable enzymes that have been cloned with activity for capturing methane: aerobic capture via soluble methane monooxygenase and anaerobic capture via methyl-coenzyme M reductase. We suggest these two enzymes may play a prominent, sustainable role in addressing our current global warming crisis.

FIGURE 1

Capturing atmospheric methane from livestock, industry and landfills. For the aerobe‐producing recombinant sMMO, methane could be converted to methanol. For the recombinant Mcr system, the methanogen performing reversed methanogenesis could convert methane to acetate by capturing both methane and carbon dioxide. Mcr, methyl‐coenzyme M reductase; sMMO, soluble methane monooxygenase.