Examination of Dechlorinating Anaerobic Microbes in Poly-chlorinated Biphenyl Contaminated Sediments in the Chesapeake Bay

Polychlorinated biphenyls (PCB) are common environmental contaminants that have been linked to many detrimental health conditions in humans and marine life. These industrially produced compounds were ubiquitously used in capacitors, transformers and frequently as coolants. PCBs were prized for their stability and lack of reactivity; however, these same properties allow PCBs to become persistent organic pollutants (POPs) in many environments. A number of different bioremediation strategies have been proposed, but as yet, no one method has been completely successful for PCB removal in the environment. Studying the microbial communities that survive within the PCB containing sediments may allow a better understanding for the anaerobic dehalogenation of these contaminants. In this study sediment samples were collected from eight locations with varying levels of PCB contaminants. Microbial DNA extractions, followed by PCR amplifications were successfully preformed utilizing a previously designed primer set used for amplifying known dechlorinating anaerobes. Restriction length polymorphisms (RFLP) analysis of the constructed clone library has shown that the diversity of this population is quite limited in a number of the Chesapeake Bay sediments. The limited diversification of anaerobes within the sediments may imply that the PCBs are acting as selection factors to facilitate the more adaptive anaerobes. Our future work will be focused on closer examination of the dominate anaerobes. Examination of the microbes associated with PCB dechlorination in contaminated sediments will provide a better understanding of this process in the environment.