Physiology and Biochemistry of the Aerobic Methane Oxidizing Bacteria

Methanotrophic bacteria grow aerobically using methane as a source of carbon and energy. They are widespread in the environment and play an important role in oxidizing methane in the environment, thereby mitigating the effects of global warming by this potent greenhouse gas. Methane monooxygenases (MMOs), which are the enzymes that catalyze the oxidation of methane, especially, the catalytically versatile soluble MMO, can cooxidize a wide range of hydrocarbons and chlorinated hydrocarbons, and have great potential as biocatalysts for bioremediation and biocatalysis. Methanotrophs can also be used to make single-cell protein from methane. Recent isolation of novel groups of thermophilic, acidophilic methanotrophs has revealed that these bacteria can even grow under extreme environmental conditions. The availability of genome sequences of several methanotrophs now opens up possibilities of postgenomic studies to investigate the regulation of methane oxidation in the laboratory and in the environment.