 |
Electron
micrograph of a four-cell cluster
of Deinococcus radiodurans.
 |
| Deinococcus
radiodurans growing on agar plates
in the presence of 6000 rads per
hour of radiation. |
A bacterium first discovered in spoiled
beef and believed sterilized by radiation
turned out to be "Conan the Bacterium"
(aka Superbug)—the most radiation-resistant
life form ever found. Deinococcus
radiodurans is highly resistant
to genotoxic chemicals, oxidative
damage, high levels of ionizing and
ultraviolet radiation, and desiccation;
it can survive 3,000 times the radiation
dose that is lethal to humans. The
capability to survive in such extreme
environments is attributed in part
to a unique DNA repair system in combination
with its chromosome copy number and
structure. Researchers supported by
the Office of Science reengineered
the microbe so that it can reduce
toxic metals and partially degrade
harmful solvents while surviving the
high radiations levels typical of
those at DOE waste sites. This was
the first time a microbe has been
engineered to have these remarkable
capabilities. The DNA of this organism
was sequenced with Office of Science
support as well.
Scientific Impact:
This work established both the capability
to engineer additional functions into
D. radiodurans and the persistence
of the added functionality despite
exposure to radiation. Studies of
this microbe will add to understanding
of sensitive enzymes responsible for
monitoring and repairing damage to
DNA caused by radiation and other
agents.
Social Impact: The
astonishing DNA repair capacities
of this organism, as well as the feasibility
of genetically modifying it, are of
interest for cleanup of radioactive
wastes. The techniques used to modify
the microbe could lead to new biological
solutions—rather than traditional,
costly "pump and treat" options—for
cleaning up environmental contamination
resulting from the production of weapons-grade
nuclear materials in years past.
Reference: K. S.
Makarova, L. Aravind, L.Tatusov, Y.
I. Wolf, E. V. Koonin, and M. J. Daly,
"Genome of the extremely radiation
resistant bacterium Deinococcus radiodurans
viewed from the perspective of comparative
genomics," Microbiology and Molecular
Biology Reviews, 65, 44-79 (2001).
H. Brim, S. McFarlan, L. Wackett,
K. W. Minton, M. Zhai, J. Fredrickson,
and M. J. Daly, "Engineering Deinococcus
radiodurans for metal remediation
in radioactive mixed waste environments,"
Nature Biotechnology, 18,
85-90 (2000).
URL: http://www.usnews.com/usnews/issue/000103/daly.htm
ftp://ncbi.nlm.nih.gov/pub/koonin/Deinococcus/
Technical Contact:
Dr. Dan Drell, Life Sciences Division,
Office of Biological and Environmental
Research, 301-903-4742
Press Contact: Jeff
Sherwood, DOE Office of Public Affairs,
202-586-5806
SC-Funding Office:
Office of Biological and Environmental
Research |
