THE BACTERIAL OXIDATION OF AROMATIC COMPOUNDS I

Abstract

Studies on the oxidation of aromatic substrates by Pseudomonas fluorescens. conducted by the technique of simultaneous adaptation, suggest that catechol is a common intermediate in the oxidation of phenol and of the members of the oxidative reaction chain that includes mandelic and benzoic acids, and that protocathechuic (3,4-dihydroxybenzoic) acid is an intermediate in the oxidation of p-hydroxybenzoic acid. The data further show that protocatechuic acid is not an intermediate in the oxidation of mandelic acid, benzoic acid and phenol, and that catechol is not an intermediate in the oxidation of p-hydroxybenzoic acid; consequently, the oxidative pathways passing through these 2 intermediates must merge, if they do so at all, at a later point. Additional polyphenolic compounds tested as possible intermediates included 2,3-dihydroxybenzoic acid, 2,3,4-and 3,4,5-trihydroxybenzoic acids, phloroglucinol, pyrogallol and hydroxyhydroquinone. The data obtained indicate that none of these compounds plays an intermediate role in the oxidation of the above-mentioned primary substrates.