Degradation of Ethylbenzene by Pseudomonas putida Harboring OCT Plasmid

We have investigated the utilization of a variety of alkylbenzenes by P. putida strains and found that a strain harboring the OCT plasmid assimilated ethylbenzene. The linkage between the determinant for the degradation of ethylbenzene (Etb⁺ phenotype) and the OCT plasmid was inferred from conjugation experiments. The growth characteristics of the strains carrying mutations in the alk genes of the OCT plasmid which determine the assimilation of /t-alkanes indicated that alkB, alkA, and alkR should be responsible for the degradation of ethylbenzene. The exposure of ethylbenzene to the P. putida strain harboring the CAM-OCT plasmid resulted in the accumulation of β-phenylethyl alcohol. A possible degradation pathway for ethylbenzene including the terminal oxidation of the alkyl side chain was proposed.