ABSTRACT
Aerobic methane oxidizing bacteria (methanotrophs) can use methane as carbon source and energy source, eliminating 10%-20% of global methane. Methanotrophs can also effectively synthesize valuable methane-derived products. This article introduced the methane oxidizing mechanism of methanotrophs, and summarized the practical application and research hotspots of methanotrophs in the field of methane emission reduction in the landfill, ventilation air methane mitigation in coal mines, valuable chemicals biosynthesis, as well as oil and gas reservoir exploration. Main factors influencing the pollutant removal and the biosynthesis efficiency in various applications were also discussed. Based on the study of large-scale cultivation of methanotrophs, some measures to benefit the application and promotion of aerobic methane oxidizing biotechnology were proposed. This includes investigating the effect of intermediate metabolites on methanotrophs activity and population structure, and exploiting economical and efficient alternative culture media and culture techniques.
Subject(s)
Biotechnology , Carbon , Culture Media/chemistry , Methane/metabolism , Methylococcaceae/metabolism , Oxidation-ReductionABSTRACT
Methanotroph microorganisms oxidize methane in four steps, producing methanol, formaldehyde, formate intermediers and eventually degrade methane to carbon dioxide and water. It is possible to separate the pathway into four steps in the cell free extract or after partial purification of the various enzymes. The key enzyme is a metalloenzyme, methane monooxygenase (MMO) which catalyses the oxidation of methane to methanol. MMO is also capable of biodegrading exceptionally harmful and stable chlorinated hydrocarbons. Produced by various industrial activities, most chlorinated hydrocarbons are toxic, potential and/or proven carcinogens and their decomposition challenges water treatment technologies.