The Burly Bacteria

Researchers have mapped out the complete gene pattern of one of the toughest bacteria known -- a bug that may be used to clean up atomic waste and radiaoactive spills.

In a study appearing in the latest edition of the journal Science, researchers report the complete sequencing of the genes in a bacteria called Deinococcus radiodurans, an organism that is able to survive and thrive in environments of extreme heat, cold, poison and radiation.

Michael J. Daly, a co-author of the study, said that having the complete genetic sequence "is like turning on a light" in a dark room for scientists who are trying to find ways to clean up polluted and radioactive dump sites.

"We've already been working with this organism, but having the gene sequence will make it go much faster," said Daly, a genetic researcher at the Uniformed Services University of the Health Sciences in Bethesda, Maryland. He is a military researcher who is developing biological ways of cleaning up radioactive and toxic wastes.

Deinococcus radiodurans is a member of a small group of microbes able to survive and reproduce in environments that would be instantly lethal for most organisms. The red-colored bacterium can survive 1.5 million rads of gamma radiation, about 3,000 times the lethal dose for humans. It can also be dried to the crispy state of a potato chip and then be revived. It also survives high doses of ultraviolet radiation that would kill most everything else.

"This organism could even survive a surge of atomic blast radiation," Daly said.

Daly said researchers now hope to harness the remarkably resilient microbe (which poses no threat to humans or other organisms) to clean up radioactive and chemically toxic dumps and spills. He said 10 million cubic yards of radioactive wastes in this country have contaminated about 70 million cubic yards of soil and some 1 trillion gallons of ground water.

Conventional cleanup methods would cost up to $300 billion, he said, but doing the job with Deinococcus radiodurans could cut those costs by 90 percent.

Daly said genes introduced into the microbe would allow it to metabolize toxic wastes, such as toluene, and to transform heavy metals that are radioactive.

The action of the microbe will not neutralize the radiation in metals, he said, but the bug could make waste less toxic and less soluble so that it does not dissolve and move into ground water.