- "...field tests so far have been blocked by objections
from environmentalists, who fear that genetic engineering may have harmful
consequences."
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- WASHINGTON -- Scientists
are working to perfect a "superbug" that they think can help
clean up toxic wastes at thousands of radioactive nuclear sites around
the world.
-
- The mighty microbe -- nicknamed "Conan the Bacterium"
-- combines the genes of two bacteria to perform a job neither could do
on its own.
-
- The composite creature "can live quite happily in
an environment with 1 million times the radiation a human cell could tolerate,"
Energy Secretary Spencer Abraham said this month.
-
- Conan works because the radiation-resistant bacterium
(Deinococcus radiodurans) shelters the microbe from lethal rays, while
its partner (Pseudomonas putida) uses its native ability to render poisons
in soil or water harmless.
-
- "Our scientists have shown that it is possible to
combine Conan's radiation-resistance properties with the capabilities of
other microbes," Abraham said. "We are ready to turn it to our
own uses."
-
- The Energy Department estimates that there are about
3,000 sites contaminated with 40 million cubic yards of toxic wastes --
many of them radioactive -- left over from the Cold War.
-
- "Some of these waste sites are really hot -- they're
cooking," said Michael Daly, a biologist at the Uniformed Services
University of the Health Sciences in Bethesda, Md.
-
- Daly and genome wizard Craig Venter, the founder of the
Institute for Genomic Research in Rockville, Md., determined the complete
sequence of the Deinococcus genome in 1999. Daly continues to work on practical
applications of the modified microbe in his laboratory.
-
- One application under development might help cancer patients
resist the unpleasant side effects of radiation therapy.
-
- "It's very exciting," Daly said in a telephone
interview. "There are more things to come that I can't talk about
yet."
-
- The destruction or taming of toxic wastes by biological
engineering is called bioremediation.
-
- For example, Conan can break down the chemical structure
of toluene -- an ingredient in explosives such as TNT -- and leave only
carbon dioxide and water.
-
- "You can't get less toxic than that," Daly
said.
-
- Conan also works on mercury, dangerous pesticides such
as chlorobenzene, and PCBs, which are carcinogenic compounds formerly used
in manufacturing.
-
- Although Conan's technology has been proved in the laboratory,
field tests so far have been blocked by objections from environmentalists,
who fear that genetic engineering may have harmful consequences.
-
- "Some people were appalled that we generated radiation-resistant
microbes that are potentially going to vaporize mercury and put it in the
atmosphere," Daly said.
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- © 2003 Star Telegram and wire service sources. All
Rights Reserved.
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- http://www.dfw.com/mld/dfw/news/nation/7345489.htm
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