In experiments repeated many times on bottom sediments from Baltimore harbor, researchers of UMBI's Center of Marine Biotechnology (COMB) and the Medical University of South Carolina (MUSC), discovered the PCB-degrading bacterium using a rapid, DNA screening method.
For several decades, environmentalists and regulators have been challenged to deal with tons of banned PCBs in the environment, released by industries for over 70 years. "This first identification of a PCB-dechlorinating, anaerobic (without oxygen) bacterium is important for bioremediation efforts and for developing molecular probes to monitor PCB degrading where they are found," says Kevin Sowers, research microbiologist at COMB. The researchers linked PCB dechlorination directly to the growth of the bacterium. It appears to live off the compound.
Jennie Hunter-Cevera, UMBI president and environmental biotechnologist, adds, "This is a great example of how man-made pollution can be handled by microorganisms through their incredible ability to adapt." The report concludes that the UMBI method could be used to identify additional PCB-degrading microbes.
Beginning in the 19th century, PCBs were made from petroleum as insulators for electrical equipment and other electronics. But, in 1979, the federal government banned them because of possible environment and human health hazards. However, all over the world, says Sowers, PCBs are still bound to bottom sediments of many rivers, harbors and bays. "Particles of PCBs persist after many years, because they don't dissolve well in water. They attach to sediment and get covered over," he says. "Unless there is some turnover, a lot of PCBs stay hidd
Contact: Steve Berberich
University of Maryland Biotechnology Institute