Transformation of o-Xylene to o-Methyl Benzoic Acid by a Dentrifying Enrichment Culture Using Toluene as The Primary Substrate

A highly enriched denitrifying mixed culture transformed o-xylene cometabolically along with toluene by methyl group oxidation. o-Methyl benzaldehyde and o-methyl benzoic acid accumulated transiently as metabolic products of o-xylene transformation. Transformation of o-methyl benzyl alcohol and o-methyl benzaldehyde occurred independently of toluene degradation and resulted in the formation of a compound coeluting with o-methyl benzoic acid on a gas chromatograph. The cometabolic relationship between toluene and o-xylene could be attributed to a mechanism linked to the initial oxidation of the methyl group.