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. ω-Oxidation of the alkyl substituents is followed by β-oxidation. It is of particular interest that cyclic acids such as cyclohexaneacetic and phenylacetic with C₂ residual carboxylic acid substituents are resistant to further oxidation by the nocardia but cyclic acids with C₁ or C₃ 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.