Genome Editing in Methanotrophic Bacteria: Potential Targets and Available Tools

Aerobic methanotrophic bacteria are prokaryotic microorganisms possessing methane monooxygenases, unique enzymes that determine their ability to utilize methane (CH4) as a growth substrate. This metabolic capability makes methanotrophs attractive objects for biotechnological applications aimed at utilizing methane for production of microbial cell protein and various target metabolites. The current raise of interest to these biotechnologies is driven by high availability of methane, which is a major component of natural gas, as well as of the biogas produced in anaerobic fermentation processes. Since aerobic methanotrophs oxidize methane at the ambient temperature and pressure, they represent natural cell factories for converting CH4 into various value-added products. Further development of biotechnologies based on methane utilization requires application of genome editing techniques to obtain producer strains with improved characteristics. For a long time, the progress in metabolic engineering of methanotrophs was hampered by their specific metabolic properties and the difficulties of handling these bacteria. Here, we present an overview of the latest achievements in the field of metabolic engineering of methanotrophic bacteria and identify the potential targets as well as the currently available tools for genome editing of these microorganisms. These techniques open up the possibility of constructing strains with biotechnologically relevant characteristics and conducting in-depth research of the metabolic features of aerobic methanotrophs.