Bug may help clean up PCB deposits
16 Jan 2002
Researchers from the University of Maryland Biotechnology Institute have discovered a strain of microbes which are capable of breaking down polychlorinated biphenyls.
The bacteria, which live in river mud, are the first microbes reported which can break the strong carbon-chlorine bonds in PCBs.
PCBs, banned since 1979, are toxic and accumulate in living tissues. Using bacteria to break them down has been a goal of researchers for some time, as the molecules are extremely stable and difficut to decompose safely. The Maryland team's discovery is the first that can break the bond in the 'ortho' position characteristic of PCBs.
The researchers, from UMBI's centre for marine biotechnology (COMB) and the Medical University of South Carolina, used a DNA screening method to identify the bacterium, which appears to live off PCBs. Reporting their work in a recent issue of the journal Environmental Microbiology, the team explains that as PCBs are poorly soluble in water, they tend to settle at the bottom of rivers and adsorb onto sediment particles.
'This first identification of a PCB-dechlorinating, anaerobic bacterium is important for bioremediation methods and for developing molecular probes to monitor PCB degrading degradation,' says COMB microbiologist Kevin Sowers. It could also help scientists identify more PCB-eating species, he adds.
