Oxidation of phenylacetic acid by Penicillium chrysogenum

Abstract

Phenylacetic acid (PA) is oxidized completely to CO2 by mycelial suspensions of a mutant of P. chrysogenum Q 176. The oxidative activity of such suspensions was greatest when the parent culture had achieved 75% of its max. growth, the total respiratory activity being highest at this time. Respiration in presence of phenylacetic acid increased over the pH range 5.6-8.4. Benzaldehyde was characterized as a product of PA oxidation. Similar suspensions oxidized benzoic, hydrocinnamic, DL-mandelic, DL- and D-hydratropic, p-hydroxyphenylacetic, p-hydroxybenzoic and benzylformic acids and benzyl alcohol, but not beta-phenylisobutyric acid. Benzaldehyde was isolated after biological oxidation of DL-mandelic acid or benzyl alcohol: acetophenone was obtained by oxidation of hydratropic acid. Benzoylformic acid does not yield benzaldehyde in the presence of the mold. The oxidation of phenylacetic acid is inhibited by mercuric or iodoacetate ions.