Bacteria that bind toxic metals: Are they the future
of nuclear waste cleanup?
|
August 26, 2005
by
Gina M. Buss Researchers in Germany have found a way to use
bacteria which are able to accumulate toxic metals and survive in nuclear
waste as a way of cleaning up toxic dumps. |
230,000 tons of nuclear waste: that’s
how much toxic metal can accumulate after 30 years of mining uranium - and
that’s just one waste pile. With all the nuclear waste production throughout the
world, this toxic metal is literally “piling up” in more and more places, and is
encroaching on inhabited areas.
During the process of generating nuclear
power and nuclear weapons, radionuclides like uranium are discharged into the
environment. These metals pose a serious ecological and health threat and
usually contaminate the soil, sediment, and waters surrounding the waste piles.
Conventional methods of cleaning up these toxic wastes are often
expensive and not very effective. The environment is in dire need of a novel
approach to waste clean-up and researchers in Germany may have the answer.
A recent study from the Institutes of Radiochemistry and Nuclear Physics
in Dresden outlines a way of using bioremediation as a means for eliminating
nuclear waste. Bioremediation is a process that uses microorganisms to return an
environment back to its original condition after it has been exposed to
contaminants.
Nuclear waste piles, such as the one in southeast Germany
that’s highlighted in the
study, are a reservoir for certain strains of
bacteria. These bacteria have evolved special mechanisms to survive in this
waste that would normally be toxic to other types of microorganisms.
The
strain Bacillus sphaericus has evolved a crystalline surface layer (S-layer)
that covers the outside of the cell. This layer is more than a protective
barrier to the bacteria, it serves to accumulate high amounts of toxic metals
such as uranium, lead, copper, aluminum, and cadmium.
Researchers are
currently seeking out ways to exploit the bacteria’s strategies. New technology
is incorporating the S-layer structure onto silicon wafers, metals, polymers,
nanoclusters, and bioceramic discs. All of these products could be used to
remove metals from contaminated water and soil.
Additionally, these
technologies could be used to recover precious metals such as platinum and
palladium from industrial waste sites and recycle them for making electronic
products.
Bacteria may be the template for new technology aimed at
nuclear waste removal. The time may be near when synthetic S-layer discs can be
placed in contaminated areas and act as sponges, cleaning up a big toxic mess.
Reference:
Pollman K, Raff J, Merroun M, Fahmy K, and
Selenska-Pobell S.
Biotechnology Advances. 2005. Article in press.
by Gina M. Buss, Copyright 2005 PhysOrg.com
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