Date of Award
12-2006
Degree Name
Master of Science
Department
Biological Sciences
First Advisor
Dr. Silvia Rossbach
Second Advisor
Dr. John Quensen
Third Advisor
Dr. Karim Essani
Fourth Advisor
Dr. Charles Ide
Access Setting
Masters Thesis-Open Access
Abstract
The Kalamazoo River is contaminated with polychlorinated biphenyls (PCBs) which are neurotoxins and suspected carcinogens. The goal of this study was to isolate, identify, and metabolically characterize PCB degrading strains of aerobic bacteria. Biphenyl enrichments resulted in the isolation of putative PCB degrading strains from different locations along the river. Based on 16S rRNA gene analysis the isolated strains were identified as belonging to the genera of Achromobacter, Acidovorax, Cellulosimicrobium, Paenibacillus, Pseudomonas, and Rhodococcus. These strains were screened for their PCB degrading ability and congener specificity. All of the isolated strains degraded PCBs via the 2,3-dioxygenase pathway. The range of PCBs degraded was limited to mono- to tri-substituted congeners. In addition, the isolated strains oxidized 2,4'-CB but accumulated problematic intermediate metabolites. These results indicate that most of the aerobic-PCB-degrading bacteria isolated in this study from the Kalamazoo River have a moderate potential to degrade the lesser chlorinated PCBs, while one strain (D1) was found to have above average PCB degrading capabilities.
Recommended Citation
Lehmkuhl, Brenton K., "Metabolic and Phenotypic Characterization of Aerobic PCB Degrading Bacteria Isolated from Kalamazoo River Sediments" (2006). Masters Theses. 4552.
https://scholarworks.wmich.edu/masters_theses/4552