Polychlorinated biphenyls (PCBs) are a mixture of 209 individual chlorinated compounds commonly known as PCB congeners. These compounds are hydrophobic and are persistent in the environment. Their use was banned in the US a few decades ago because of harmful health effects. Therefore, detection of PCBs in environmental samples is increasingly important. To that end, we have developed a two-step simple and sensitive method for the detection of total PCBs. Specifically, our method involves dechlorination of PCBs to biphenyl followed by detection of biphenyl using a whole cell sensing system as the detection system. The whole cell sensing system consists of cells of the strain Pseudomonas pseudoalcaligenes KF707 harboring plasmid pSD7000. Plasmid pSD7000 contains the gene of lacZ, a reporter protein under the control of the bph operon. The detection is achieved through the emission of light afforded by the expression of reporter protein triggered by the presence of biphenyl. Due to the fact that this operon is activated only by few PCB congeners, a chemical dechlorination method was employed to convert all PCBs to biphenyl, and thus all the PCBs present in a given sample are able to be detected. The results showed that PCB congeners were rapidly (30 min) and efficiently (>98.5%) dechlorinated to biphenyl using a Mg/K2PdCl6 catalyst, and the biphenyl could be subsequently quantified using the whole cell sensing system. This hybrid analytical method that combines classical dechlorination with novel biosensing methods may find applications in the on-site monitoring of PCBs contamination levels.
|Number of pages||12|
|Journal||Toxicological and Environmental Chemistry|
|State||Published - Jul 2005|
Bibliographical noteFunding Information:
We thank the National Institute of Environmental Health Sciences (Grant P42 ES 07380 to S. D. and E. D.) for the support of this research. We also thank Dr. K. Furukawa for supplying the Pseudomonas pseudoalcaligenes KF707 strain. J. F. is a National Science Foundation Pre-doctoral Fellow and a NSF-IGERT Fellow.
- Polychlorinated biphenyl
- Whole cell sensing system
- bph operon
ASJC Scopus subject areas
- Environmental Chemistry
- Health, Toxicology and Mutagenesis