THE BACTERIAL OXIDATION OF AROMATIC COMPOUNDS V. C 14

Abstract

Catechol, an intermediate in this dissimilation, was isolated and degraded. Catechol derived from carboxyl-labeled benzoic acid is inactive, while that derived from benzoic acid-1-C14 has the same specific activity as the parent compound. This has been interpreted as proof of the identity of the aromatic nucleus in benzoic acid and in the catechol produced from it. All the radioactivity of the catechol derived from benzoic acid-l_Cl4 is in C atoms 1 and 2, indicating that in the conversion one hydroxyl group of catechol replaces the carboxyl of benzoate while the 2d hydroxyl is attached in ortho juxtaposition. As a result of the complete oxidation of benzoic acid, the radioactivity of the carboxyl group is found almost exlusively in respiratory CO2; that of C atom 1 is largely found in CO2, but a significant percentage appears in the bacterial cells and in the supernatant liquid.