Cometabolic Bioremediation

Abstract

Cometabolic bioremediation is probably the most underappreciated bioremediation strategy currently available. Cometabolism strategies stimulate only indigenous microbes with the ability to degrade the contaminant and cosubstrate, e.g., methane, propane, toluene, and others. This highly targeted stimulation insures that only those microbes that can degrade the contaminant are targeted, thus reducing amendment costs, well and formation plugging, etc. Cometabolic bioremediation has been used on some of the most recalcitrant contaminants, e.g., PCE, TCE, MTBE, TNT, dioxane, atrazine. Methanotrophs have been demonstrated to produce methane monooxygenase, an oxidase that can degrade over 1000 compounds. Cometabolic bioremediation also has the advantage of being able to degrade contaminants to trace concentrations, since the biodegrader is not dependent on the contaminant for carbon or energy. In the Gulf of Mexico and in the Arctic Tundra, we have recently found that natural attenuation can be a cometabolic process also. Increasingly we are finding that in order to protect human health and the environment that we must remediate to lower and lower concentrations, especially for compounds like endocrine disrupters and trace organics, thus cometabolism may be the best and may be the only possibility that we have to bioremediate some contaminants.