Abstract:Burkholderia xenovorans LB400 is a strain of polychlorinated biphenyls degrading bacteria PCBs. This organism also cooxidizes chlorinated biphenyl (CB) congeners containing from one to six chlorine substituents. In recent years, LB400 has become a model organism for study of the biochemistry and molecular biology of CB metabolism in prokaryotes, because of excellent degradability and a broad spectrum of chlorinated biphenyl (CB) congeners. At present, the research on strain LB400 is mainly focused on degradation genes, enzymes and enzymes evolution, while its degradation pathway, substrate range and related mechanism of PCBs have been widely discussed; Furthermore, there are few studies on regulatory genes related to degradation of PCBs. This paper focuses on the degradation of polychlorinated biphenyls, and describes its metabolic pathway, related genes and enzyme system and artificial evolution. we hope to provide a reference for the further study of the application of Burkholderia xenovorans LB400 and other polychlorinated biphenyls degradation strains.