[5][6] Some of the molecules that are cometabolically degraded by bacteria are xenobiotic, persistent compounds, such as PCE, TCE, and MTBE, that have harmful effects on several types of environments.
[6] Reductive dehalogenation often results in the partial dechlorination of the PCE, giving rise to toxic compounds such as TCE, DCE, and vinyl chloride.
Pseudomonas st. OX1 can degrade PCE under aerobic conditions by using toluene-o-xylene monooxygenase (ToMO), an enzyme they produce to derive energy and carbon from toluene and several other aromatic compounds.
[6] However, the difficulties and high costs of maintaining the growth-substrates of the organisms capable of cometabolising these hazardous compounds and providing them an aerobic environment have led to the limited field-scale application of cometabolism for pollutant solvent degradation.
Recently, this method of remediation has been proposed to be improved by the substitution of the synthetic aromatic growth-substrates (e.g. toluene) of these bacteria with cheap, non-toxic plant secondary metabolites.