Scientists Seek Indestructible Bugs To Eat Nuclear Waste

["Sandy Perle" <sandyfl@EARTHLINK.NET>]

SAVANNAH RIVER SITE, S.C. (Nov. 16) - Eight years ago, scientists 

using a metal rod here to probe the radioactive depths of a nuclear-

waste tank saw something that shocked them: a slimy, transparent 

substance growing on the end of the rod.



They took the specimen into a concrete-lined vault where technicians 

peered through a 3-foot-thick window and, using robot arms, smeared a 

bit of the specimen into a petri dish. Inside the dish they later 

found a colony of strange orange bacteria swimming around. The 

bacteria had adapted to 15 times the dose of radiation that it takes 

to kill a human being. They lived in what one scientific paper calls 

a "witches' brew" of toxic chemicals.

   

It was a step forward for the U.S. Department of Energy, which has 

been looking for a few good bugs -- in particular, members of an 

emerging family of microbes that scientists call "extremophiles." 

These microbes can survive in some of Earth's most inhospitable 

environments, withstanding enormous doses of radiation, thriving at 

temperatures above boiling, and mingling with toxic chemicals that 

would kill almost anything else.



That makes them a potentially valuable tool in the Energy 

Department's effort to clean up vast amounts of nuclear waste, 

including the Savannah River Site near Augusta, Ga., and the Hanford 

Site near Richland, Wash. The department says it could cost as much 

as $260 billion to clean up its messes with conventional methods, 

which rely heavily on chemical treatment and robots. Using 

extremophiles could slash that bill.



Extremophiles eliminate toxins by ingesting them and breaking them 

down into relatively harmless components. The microbes also can 

reduce the hazard of radioactive wastes by changing them into 

insoluble forms that are much less likely to leak into aquifers and 

streams. Outgoing Energy Secretary Spencer Abraham predicted this 

year that "in the not-too-distant future," extremophiles will be 

cleaning up nuclear waste and munching the pollutants of coal-fired 

power plants, including carbon dioxide, one of the causes of global 

warming. The National Aeronautics and Space Administration thinks if 

it can understand the mechanism that the bugs use to survive 

radiation, it might be able to use it to protect space crews against 

radiation on long voyages. The National Institutes of Health hopes 

the microbes' peculiar powers might help cancer patients survive more-

intensive radiation therapy.



So far, scientists say that the extremophiles they have found in 

nature aren't harmful to humans. Laboratory-engineered modifications 

of these bugs, however, are likely to cause some controversy because 

no one knows what their long-term effects might be.



The berry-shaped bug discovered at the Savannah River Site was 

christened Kineococcus radiotolerans. Scientists have probed 95% of 

its genetic structure. They know what it does and what it eats -- it 

loves malt sugar -- but after 50 years of studying these sorts of 

bugs, they have no idea how they survive. Radiation shatters the 

genetic structures of living things, but extremophiles snap 

themselves back together in a matter of hours.



Christopher Bagwell, a microbiologist here, says Kineococcus has 

shown the ability to break down herbicides, industrial solvents, 

chlorinated compounds and other toxics, all while growing in a 

radioactive environment that shrivels other living things and turns 

glass brown.



Scientists know of at least a dozen extremophiles. The first was 

discovered in 1956 in Corvallis, Ore. Scientists were zapping cans of 

horse meat with high radiation, trying to establish the preservative 

value of food irradiation. One can developed an ominous bulge. 

Inside, the scientists isolated pink bacteria they had never seen 

before.



They gave it the scientific name Deinococcus radiodurans. But 

researchers were so amazed by the bug's resilience that some years 

later, they nicknamed it "Conan the Bacterium," spawning a folklore 

and debate among scientists that continues today. Because the 

microbes endure radiation at levels higher than any natural source, 

some scientists have argued that they must have ridden in on comets. 

Others speculate that they were the Earth's first residents after the 

planet was born in a radioactive explosion.



"Because of the amazing abilities of these organisms, they sort of 

bring out the poet in people," says John R. Battista, a 

microbiologist at Louisiana State University. He says speculation 

about outer space origins is like engaging in "mythology."



Extremophiles have recently been found on barren mountain tops and in 

the frozen plains of Antarctica, Dr. Battista says. He believes they 

are simply harmless, opportunistic creatures that have found a way to 

survive in conditions of severe drought, which, he says, damages 

cells in much the way radiation does. "It just waits until it gets 

dried out and then it gets blown somewhere else."



The original Conan proved to be a wimp among extremophiles. It could 

handle radiation, but not the solvent toluene and other chemicals 

normally found in bomb makers' wastes. So, in 1997, the Energy 

Department started work on a genetically manipulated bug that 

researchers called Super Conan.



Super Conan now lives in a petri dish at the Uniformed Services 

University of the Health Sciences, a U.S. military research facility 

in Bethesda, Md. It can handle nasty chemicals as well as radiation, 

but the researcher who developed it, Michael J. Daly, says the 

government is afraid to let it out.



"We're at a point where we could do some field trials," he says, 

adding that his sponsors at the Energy Department doubt the public is 

ready for the release of this laboratory-engineered bug into the 

environment. It might eat nuclear wastes, but they worry about what 

else might it do, he says.



Rather than confront such touchy matters, the department is confident 

it can find Super Conan's equivalent in nature, says Ari Patrinos, 

the department's director of biological and environmental research. 

He estimates that fewer than 1% of the Earth's bacteria forms have 

been identified: "There are plenty out there for our needs. We just 

have to pick and choose."



That's where Kineococcus comes in. The Savannah River Site, slapped 

together in the early 1950s to keep the U.S. ahead of the Soviet 

Union in the race to produce hydrogen bombs, has 49 underground 

storage tanks containing 35 million gallons of radioactive waste. The 

Energy Department has a much bigger mess at the Hanford site, a World 

War II weapons plant where leaking tanks have contaminated 80 square 

miles of groundwater with radiation and toxic chemicals.



Because the new orange bug made its home in nuclear wastes, no one 

can argue that putting it back there would be unnatural, say the 

scientists here. They believe they can grow kineococcus in petri 

dishes and then inject it into tanks and underground plumes of 

leaking wastes.



But Dr. Bagwell thinks it will take five more years of peering into 

the bug's genes before attempting such experiments. Twenty percent of 

the microbe's genetic structure, he says, involves "unknown 

functions."





----------------------------------------------------------------

Sandy Perle 

Senior Vice President, Technical Operations 

Global Dosimetry Solutions, Inc. 

2652 McGaw Avenue

Irvine, CA 92614



Tel: (949) 296-2306 / (888) 437-1714 Extension 2306 

Fax:(949) 296-1144



Global Dosimetry Website: http://www.dosimetry.com/ 

Personal Website: http://sandy-travels.com/ 



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