Abstract

Aromatic compounds are widely distributed in nature. They are found as lignin components, aromatic amino acids, and xenobiotic compounds, among others. Microorganisms, mostly bacteria, degrade an impressive variety of such chemical structures. Various aerobic aromatic catabolic pathways have been reported in bacteria, which typically consist of activation of the aromatic ring through oxygenases or CoA ligases and ring cleavage of di- or trihydroxylated intermediates or dearomatized CoA derivatives. We survey almost 900 sequenced bacterial genomes for the presence of genes encoding key enzymes of aromatic metabolic pathways, including ring-cleavage enzymes as well as enzymes activating aromatics or dearomatizing CoA derivatives. The metabolic diversity is discussed from two angles: the spread of such key activities among different bacterial phyla and the overall metabolic potential of members of bacterial genera.