Microorganisms can be harnessed to remove primary pollutants including chlorinated ethenes (e.g., TCE and VC) and heavy metals (e.g., U(VI) and Cr(VI)) from various environmental settings. One of the biological reactions employed to remove chlorinated ethenes from soil or groundwater environment is cometabolism by methanotrophs, i.e., the organisms that utilize methane as the energy and carbon source. Methanotrophic cometabolism is mediated by methane monooxygenases, the enzymes methanotrophs express to mediate methane turnover to methanol, in a reaction that requires methane to serve as the growth substrate. Cometabolic biodegradation have been overlooked for years, mainly due to the relative cumbersomeness of its practical application compared to reductive dechlorination (using Dehalococcoides spp.); however, recent discoveries of unconventional methanotrophs have expanded applicability of cometabolic bioremediation. In our lab, we are developing cometabolic biodegradation technology using these 'unconventional' methanotrophs for implementation in the environments where reductive dechlorination is not applicable.