Abstract
The biodegradation of polychlorinated biphenyls (PCBs) has been studied extensively as these compounds are toxic to living organisms. The recent development of a genome-based analysis demonstrated that PCB degraders have various metabolic genes for degrading xenobiotics. The presence of many putative genes coding for oxygenases suggested that these degraders have increased their catabolic versatility. The analysis of crystal structures has also progressed in the past few years, and the analysis of reaction intermediates has revealed reaction mechanisms. These results can be applied to the creation of new catalytic functions by extending the substrate specificity of enzymes. A thermophilic PCB degrader was isolated and characterized. There are still difficulties with using PCB degraders for bioremediation. Physiological as well as ecological studies which clarify suitable conditions for degradation should be done for the development of PCB degradation in contaminated soil and sediments.
