Microbial Hydrocarbon Co-oxidation: I. Oxidation of Mono- and Dicyclic Hydrocarbons by Soil Isolates of the Genus

Nocardia cultures, isolated from soil by use of n -paraffins as the sole carbon source, have been shown to bring about significant oxidation of several methyl-substituted mono- and dicyclic aromatic hydrocarbons. Oxygen uptake by washed cell suspensions was not a reliable indicator of oxidation. Under co-oxidation conditions in shaken flasks, o - and p -xylenes were oxidized to their respective mono-aromatic acids, o -toluic and p -toluic acids. In addition, a new fermentation product, 2, 3-dihydroxy- p -toluic acid, was found in the p -xylene oxidation system. Of 10 methyl-substituted naphthalenes tested (1-methyl, 2-methyl, 1, 3-dimethyl, 1, 4-dimethyl, 1, 5-dimethyl, 1, 8-dimethyl, 1, 6-dimethyl, 2, 3-dimethyl, 2, 6-dimethyl, 2, 7-dimethyl), only those containing a methyl group in the β position were oxidized at this position to the mono acid.