The effect of terpenes on the biodegradation of polychlorinated biphenyls by Pseudomonas stutzeri

The effect of two terpenes, carvone and limonene, on the biodegradation of DELOR 103, a commercial mixture of polychlorinated biphenyls (PCBs), by Pseudomonas stutzeri, an isolate from long-term PCB-contaminated soil, was studied in detail. The addition of both carvone and limonene as potential inducers of the dioxygenase metabolic pathway exerted an enhancing effect on PCB biodegradation when glycerol and xylose were used as carbon sources, whereas no such effect could be determined with biphenyl and glucose as substrates. Promising biodegradation values were determined with xylose as carbon source and carvone as terpene inducer. In this system, 30–70% of the congeners were degraded in the presence of 10 mg l−1 and 20 mg l−1 carvone, respectively, irrespective of the used concentration, whereas only 7–37% of individual PCB congeners were eliminated from the system without terpene addition.