Biodegradation of mono-hydroxylated PCBs by Burkholderia xenovorans.
Three hydroxylated derivatives of PCBs, 2'-hydroxy-4-chlorobiphenyl (2'-OH-4-CB), 3'-hydroxy-4-chlorobiphenyl (3'-OH-4-CB), and 4'-hydroxy-4-chlorobiphenyl (4'-OH-4-CB), were transformed by the PCB degrader, Burkholderia xenovorans. When the bacterium was growing on biphenyl (biphenyl pathway-inducing conditions), all three hydroxylated isomers were transformed. However, only 2'-OH-4-CB was transformed by the bacterium growing on succinate (conditions non-inductive of the biphenyl pathway). Gene expression analyses showed a strong induction of key genes of the biphenyl pathway (bph) when cells were grown on biphenyl, which is consistent with the transformation of the three isomers by biphenyl-grown cells. When cells were grown on succinate, only exposure to 2'-OH-4-CB resulted in expression of biphenyl pathway genes, which suggests that this isomer was capable of inducing the biphenyl pathway. These results provide the first evidence that bacteria are able to metabolize PCB derivatives hydroxylated on the non-chlorinated ring.
Department of Civil and Environmental Engineering, Temple University, Philadelphia, PA 19122, USA. r.tehrani@temple.edu
Rouzbeh
R
Tehrani
Monica M
MM
Lyv
Rashid
R
Kaveh
Jerald L
JL
Schnoor
Benoit
B
Van Aken
D001711:Biotransformation; D001713:Biphenyl Compounds / Q000378:metabolism; D019117:Burkholderia / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D020869:Gene Expression Profiling; D006900:Hydroxylation; D053858:Metabolic Networks and Pathways / Q000235:genetics; D011078:Polychlorinated Biphenyls / Q000378:metabolism*; D019802:Succinic Acid / Q000378:metabolism
D001713:Biphenyl Compounds; D011078:Polychlorinated Biphenyls; D019802:Succinic Acid; C010574:biphenyl