Anaerobic metabolism of aromatic compounds

Aromatic compounds constitute a class of organic molecules that are of major importance in the global storage and cycling of carbon. While microbial degradation or alteration of aromatic compounds by aerobic microorganisms is well known and major degradative pathways have been elucidated, anoxic degradative pathways are poorly understood. This is partially the result of difficulties in working with anaerobic procedures, but also because the anaerobic metabolism of aromatic compounds was previously thought to be a minor degradative route in nature. Scheline reviewed anaerobic metabolism in the gastrointestinal tract from a pharmacological point of view and includes some information on reactions involving aromatic compounds. Anaerobic degradation of aromatic amino acids has been reviewed by Barker. Ring reduction, co-metabolism of substrates, and interspecies hydrogen transfer result in the anaerobic metabolism of a wide range of substituted aromatic compounds. The activity of anaerobes is important in carbon cycling in anoxic habitats and for the removal of toxic compounds released into the environment.