MINNEAPOLIS-ST. PAUL -- Bacteria that stand up to high-level radiation have been engineered to attack pollutants commonly found at radioactive waste sites. The bacteria, the product of work led by University of Minnesota biochemist Larry Wackett, could be further engineered to completely clean up organic solvents at waste sites. The work is published in the October issue of Nature Biotechnology.
The bacteria don't naturally "eat" pollutants, but Wackett inserted genes that enabled the bacteria to attack--but not completely digest--solvents such as toluene and chlorobenzene, which are commonly used as carrier fluids for radioactive materials. Wackett said that with the addition of more genes, the bacteria may be engineered to completely digest the solvents, which can cause severe environmental damage. And there are plenty of solvents to digest: In the United States alone, approximately 3,000 nuclear waste sites still await cleanup.
The bacteria, named Deinococcus radiodurans, were discovered about 20 years ago in a can of irradiated meat, said Wackett.
"When exposed to radiation, the bacteria suffer chromosomal breakage and other damage," he explained, "but they thrive because they have tremendous repair mechanisms." In experiments conducted with colleagues Mike Daly and Ken Minton of the Uniformed Services University of the Health Sciences in Bethesda, Md., Wackett found that bacteria placed in a high-energy gamma-ray field were able to attack the pollutants with the same efficiency as did bacteria subjected to no radiation. Wackett said he and his colleagues are studying the genome of D. radiodurans to learn exactly how its metabolic machinery works. That information will be used to engineer the additional genes necessary to enable the organism to completely digest pollutants.
Materials provided by University Of Minnesota. Note: Content may be edited for style and length.
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