Thermophilic and thermotolerant aerobic methanotrophs

The review generalizes the modern data on the taxonomic, structural, and functional diversity of aerobic methanotrophs growing at 25-50A degrees C (Methylococcus capsulatus), 30-62A degrees C (Methylocaldum szegediense, Methylocaldum gracile, and Methylocaldum tepidum), and 50-65A degrees C (Methylothermus thermalis), which belong mainly to the Gammaproteobacteria. The specific features of adaptation of these methanotrophs to the temperature influences are considered on the metabolic and genetic levels. The recent sensational reports on the discovery and primary characterization of thermoacidophilic methanotrophs of the phylum Verrucomicrobia surviving at extreme pH (1-2) and temperature (65A degrees C) values, corresponding to extremely low levels of CH4 and O-2 solubility, are analyzed. The possibilities of implementation of the biotechnological potential of thermophilic and thermotolerant methanotrophs are discussed.