Dichlorobiphenyl degradation by an uncharacterized Pseudomonas species, strain CPE1, in a fixed film bioreactor

A biofilm of the polychlorobiphenyl degrading Pseudomonas sp. CPE1 strain, developed on frosted glass beads, was found to be capable of extensively dechlorinating dichlorobiphenyls in an aerobic fixed bed bioreactor continuously fed with biphenyl. CPE1 biofilm displayed the capability of degrading chlorobenzoic acids, the main metabolites of dichlorobiphenyl degradation, that CPE1 strain had never degraded in the state of suspended cells. It was not possible to isolate from the bioreactor broth any microorganisms capable of such degradation activity. Thus, the dichlorobiphenyl mineralization capability displayed by the biofilm system can be ascribed either to CPE1 or CPE1 biovariants which exhibited new metabolic activities as a consequence of the immobilization process.