Efficiency of chlorocatechol metabolism in natural and constructed chlorobenzoate and chlorobiphenyl degraders.

Aims: A possibility for the complementation of both ortho- and meta-cleavage pathway for chlorocatechols in one strain and its impact on degradation of chlorobenzoates accumulated during degradation of polychlorinated biphenyls was investigated.

Methods And Results: Genes responsible for ortho-cleavage of chlorocatechols were subcloned into two biphenyl degraders and the activities of chlorocatechol dioxygenases responsible for ortho- and meta-cleavage in these hybrid strains were monitored spectrophotometrically and also electrochemically by ion-selective electrode.

Conclusions: While strain Pseudomonas fluorescens S12/C apparently gained metabolic advantage from this gene manipulation, strain Burkholderia cepacia P166/C did not express better degradation features in comparison with the parental strain.

Characterization of polychlorinated biphenyl-degrading bacteria isolated from contaminated sites in Czechia.

Biphenyl-utilizing polychlorinated biphenyls (PCB)-degrading bacteria were isolated from sites highly contaminated by PCBs, and their degradation abilities were determined using GC for typical commercial PCB mixtures (Delor 103 and Delor 106). Out of twelve strains which utilized biphenyl as a sole source of carbon and energy, strains Pseudomonas alcaligenes KP2 and P. fluorescens KP12, characterized by the BIOLOG identification system and the NEFERM test, were shown to significantly co-metabolize the PCB mixture Delor 103.