Oxidation of alkyl-substituted cyclic hydrocarbons by a Nocardia during growth on n-alkanes.

Nocardia 107-332, a soil isolate, oxidizes short-chain alkyl-substituted cyclic hydrocarbons to cyclic acids while growing on n-alkanes. Cyclic acids are produced also from relatively long-chain alkyl-substituted cyclics such as n-nonylbenzene or n-dodecylbenzene which alone support growth in a mineral-salts medium. omega-Oxidation of the alkyl substituents is followed by beta-oxidation. It is of particular interest that cyclic acids such as cyclohexaneacetic and phenylacetic with C(2) residual carboxylic acid substituents are resistant to further oxidation by the nocardia but cyclic acids with C(1) or C(3) substituents are readily oxidized and utilized for growth. The specificity of microbial oxidations is demonstrated by the conversion of p-isopropyltoluene (p-cymene) to p-isopropylbenzoic acid in n-alkane, growth-supported nocardia cultures.