Transformation of hydroxylated derivatives of 2,5-dichlorobiphenyl and 2,4,6-trichlorobiphenyl by Burkholderia xenovorans LB400

• Published in: Environmental science and pollution research international Vol. 21; no. 10; pp. 6346 - 6353
• Main Authors: Tehrani, Rouzbeh, Lyv, Monica M, Van Aken, Benoit
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.05.2014; Springer Berlin Heidelberg; Springer Nature B.V
• Subjects: Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; bacteria; Biodegradation; Biotransformation; biphenyl; Burkholderia; Burkholderia - metabolism; Carbon; Carbon sources; Chlorine; Chlorobenzoates - metabolism; Contaminants; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental Pollutants - metabolism; Experiments; Gene expression; genes; Genetic transformation; Hydroxylation; Metabolites; PCB; PCB mixtures in a complex world; pollution; Polychlorinated biphenyls; Polychlorinated Biphenyls - metabolism; Sediments; Toxicity; Waste Water Technology; Water Management; Water Pollution Control; Borja Spain; Spain; Biodegradation; Hydroxylated polychlorinated biphenyls; LB400; Biphenyl pathway; Trichlorobiphenyl; Dichlorobiphenyl
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-013-1629-6

The polychlorinated biphenyl (PCB)-degrading bacterium, Burkholderia xenovorans LB400, was capable of transforming three hydroxylated derivatives of 2,5-dichlorobiphenyl (2,5-DCB) (2′-hydroxy- (2′-OH-), 3′-OH-, and 4′-OH-2,5-DCB) when biphenyl was used as the carbon source (i.e., biphenyl pathway-inducing condition), although only 2′-OH-2,5-DCB was transformed when the bacterium was growing on succinate (i.e., condition non-inductive of the biphenyl pathway). On the contrary, hydroyxlated derivatives of 2,4,6-trichlorobiphenyl (2,4,6-TCB) (2′-OH-, 3′-OH-, and 4′-OH-2,4,6-TCB) were not significantly transformed by B. xenovorans LB400, regardless of the carbon source used. Gene expression analyses showed a clear correlation between the transformation of OH-2,5-DCBs and expression of genes of the biphenyl pathway. The PCB metabolite, 2,5-dichlorobenzoic acid (2,5-DCBA), was produced following the transformation of OH-2,5-DCBs. 2,5-DCBA was not further transformed by B. xenovorans LB400. The present study is significant because it provides evidence that PCB-degrading bacteria are capable of transforming hydroxylated derivatives of PCBs, which are increasingly considered as a new class of environmental contaminants.