Anaerobic oxidation of aromatic compounds and hydrocarbons.

Aromatic compounds and hydrocarbons have in common a great stability due to resonance energy and inertness of CbondH and CbondC bonds. It has been taken for granted that the metabolism of these compounds obligatorily depends on molecular oxygen. Oxygen is required first to introduce hydroxyl groups into the substrate and then to cleave the aromatic ring. However, newly discovered bacterial enzymes and reactions involved in oxidation of aromatic and hydrocarbon compounds to CO(2) in the complete absence of molecular oxygen have been discovered. Of special interest are two reactions: the reduction of the aromatic ring of benzoyl-coenzyme A and the addition of fumarate to hydrocarbons. These reactions transform aromatic rings and hydrocarbons into products that can be oxidized via more conventional beta-oxidation pathways.