cometabolism

Cometabolism is a phenomenon where an enzyme or microorganism degrades a compound that it does not normally use as a source of energy or carbon. This means the enzyme or organism is not gaining any direct benefit from the breakdown of the cometabolized substance. Instead, the degradation occurs because the enzyme or organism is actively metabolizing a different, primary substrate.

This process is often observed in the environment when microorganisms break down pollutants that are not typically found in their natural habitat. For example, certain bacteria that normally degrade simple sugars can, through the action of their existing enzymes, also degrade more complex or toxic compounds like chlorinated solvents. These solvents are not their food source, but the enzymes involved in their primary metabolism can inadvertently modify or break them down.

Cometabolism plays a significant role in the natural attenuation of many environmental contaminants. It can contribute to the removal of recalcitrant pollutants from soil and groundwater. However, it can also lead to the formation of intermediate compounds, some of which may be more or less toxic than the original pollutant. Understanding cometabolism is crucial for bioremediation strategies aimed at cleaning up contaminated sites. Researchers investigate which microorganisms and enzymes are involved and under what conditions cometabolism is most effective.