TY - JOUR
T1 - CIcR-based biosensing system in the detection of cis-dihydroxylated (chloro-)biphenyls
AU - Feliciano, Jessika
AU - Xu, Shifen
AU - Guan, Xiyuan
AU - Lehmler, Hans Joachim
AU - Bachas, Leonidas G.
AU - Daunert, Sylvia
N1 - Funding Information:
Acknowledgements The project described was supported by grant number P42 ES 07380 from the National Institute of Environmental Health Sciences (NIEHS), NIH and by grant number CHE-9820808 from the National Science Foundation. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NIEHS, NIH. We also thank Dr. A. M. Chakrabarty for supplying the pSMM50R-B′ plasmid and the PRS4020 strain. JF thanks the National Science Foundation for a Predoctoral Fellowship and for a NSF-IGERT Fellowship.
PY - 2006/7
Y1 - 2006/7
N2 - Polychlorinated biphenyls (PCBs) are a group of organic pollutants that are persistent when released into the environment. Among the metabolites of PCBs, dihydroxylated PCBs are also considered as toxic compounds. Various studies have shown that dihydroxylated PCBs affect the reproductive, immune, nervous, and endocrine systems. Detection of these chemicals in environmental and biological samples could provide first-hand information about their levels and lead to a better understanding of their role in toxicity. To that end, we developed a sensing system for the detection of dihydroxylated PCBs based on the clc operon. The Pseudomonas putida clc operon encodes a catabolic pathway for degradation of chlorocatechols, which are major metabolites of a large number of chlorinated compounds. In P. putida, the expression of these genes is regulated by a protein encoded by the gene clcR located upstream from the clcABD genes. We demonstrate here for the first time that dihydroxy PCBs can also induce the clc operon. Our sensing system employs P. putida bacteria harboring a plasmid in which the reporter gene, lacZ, is under the control of the regulatory protein ClcR. Consequently, when exposed to dihydroxy PCBs, the bacteria express β-galactosidase in an amount related to the concentration of the corresponding dihydroxy PCB. Various dihydroxylated PCBs, differing in the number and position of chlorines and in the position of hydroxyls, were tested for their ability to induce expression of β-galactosidase. Detection limits as low as 1×10-6 mol L-1 were obtained for various dihydroxylated PCBs.
AB - Polychlorinated biphenyls (PCBs) are a group of organic pollutants that are persistent when released into the environment. Among the metabolites of PCBs, dihydroxylated PCBs are also considered as toxic compounds. Various studies have shown that dihydroxylated PCBs affect the reproductive, immune, nervous, and endocrine systems. Detection of these chemicals in environmental and biological samples could provide first-hand information about their levels and lead to a better understanding of their role in toxicity. To that end, we developed a sensing system for the detection of dihydroxylated PCBs based on the clc operon. The Pseudomonas putida clc operon encodes a catabolic pathway for degradation of chlorocatechols, which are major metabolites of a large number of chlorinated compounds. In P. putida, the expression of these genes is regulated by a protein encoded by the gene clcR located upstream from the clcABD genes. We demonstrate here for the first time that dihydroxy PCBs can also induce the clc operon. Our sensing system employs P. putida bacteria harboring a plasmid in which the reporter gene, lacZ, is under the control of the regulatory protein ClcR. Consequently, when exposed to dihydroxy PCBs, the bacteria express β-galactosidase in an amount related to the concentration of the corresponding dihydroxy PCB. Various dihydroxylated PCBs, differing in the number and position of chlorines and in the position of hydroxyls, were tested for their ability to induce expression of β-galactosidase. Detection limits as low as 1×10-6 mol L-1 were obtained for various dihydroxylated PCBs.
KW - β-galactosidase
KW - Clc operon
KW - PCB
KW - Reporter gene
KW - Whole-cell biosensor
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U2 - 10.1007/s00216-006-0505-3
DO - 10.1007/s00216-006-0505-3
M3 - Article
C2 - 16791559
AN - SCOPUS:36349002938
VL - 385
SP - 807
EP - 813
JO - Fresenius Zeitschrift fur Analytische Chemie
JF - Fresenius Zeitschrift fur Analytische Chemie
SN - 0016-1152
IS - 5
ER -