MICROBIAL-DEGRADATION OF POLYCHLORINATED-BIPHENYLS IN AQUATIC ENVIRONMENTS

Two bacterial strains belonging to the genus Pseudomonas were isolated from a lake sediment by using p-chlorobiphenyl as a sole carbon source. Metabolic degradation of various polychlorinated biphenyls (PCBs) was investigated. Some of PCBs were converted to chlorinated benzoic acids, and total mineralization was observed for monochlorinated and monobrominated biphenyls. Biodegradation kinetics was studied in shake cultures and in soil, both in the presence and absence of an alternative carbon source. The results showed that PCBs degrade better in the presence of another substrate, and that the solubility of PCBs in water and the desorption rate from soil plays a significant part in determining the degradation rate.