Abstract

PCBs are recalcitrant due their chemical stability and hydrophobicity. In PCB-contaminated sediments, biologically-mediated dechlorination results in reduced toxicity and less bioaccumulation. In the environment, however, these compounds biodegrade slowly and incompletely, making intrinsic bioremediation less desirable for the management of PCB-contaminated sites. We have been working on a technology to stimulate the in situ reductive dechlorination of PCBs in contaminated sediment. Presently, the total number of PCB-dechlorinating microbes in natural samples cannot be quantified; therefore, we cannot determine whether enrichment and/or stimulation techniques result in the growth of dechlorinating bacteria in the environment. If these organisms are identified, molecular-based techniques could be developed to determine which organisms are present at a particular site and how their numbers change with time. In addition, without PCB-dechlorinating bacterial isolates or highly enriched and defined dechlorinating microbial cultures, our Understanding of the physiology of PCB-dechlorination (e.g., growth and biodegradation rates, nutritional needs, etc.) is limited, and thus our efforts to engineer a sediment bioremediation system are significantly hampered. In this proposed research we will: (1) develop highly enriched PCB-dechlorinating cultures (2-3 populations) or obtain PCB-dechlorinating isolates from Baltimore Harbor, Hudson River, Palos Verdes, and Waukegon Harbor sediment and identify the dechlorinators present, and (2) investigate the H2 affinity and threshold, electron donor specificity, electron acceptor specificity, and PCB congener specificity of these organisms.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of Environmental Health Sciences (NIEHS)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21ES012810-02
Application #
6803962
Study Section
Special Emphasis Panel (ZES1-SET-A (R1))
Program Officer
Thompson, Claudia L
Project Start
2003-09-30
Project End
2007-07-31
Budget Start
2004-08-01
Budget End
2007-07-31
Support Year
2
Fiscal Year
2004
Total Cost
$183,197
Indirect Cost

  Institution

Name
University of Minnesota Twin Cities
Department
Engineering (All Types)
Type
Schools of Engineering
DUNS #
555917996
City
Minneapolis
State
MN
Country
United States
Zip Code
55455