COLUMBUS, Ohio -- Researchers are studying some common soil bacteria that "inhale" toxic metals and "exhale" them in a non-toxic form.
The bacteria might one day be used to clean up toxic chemicals left over from nuclear weapons production decades ago.
Using a unique combination of microscopes, researchers at Ohio State University and their colleagues were able to glimpse how the Shewanella oneidensis bacterium breaks down metal to chemically extract oxygen.
The study, published online this week in the journal Applied and Environmental Microbiology, provides the first evidence that Shewanella maneuvers proteins within the bacterial cell into its outer membrane to contact metal directly. The proteins then bond with metal oxides, which the bacteria utilize the same way we do oxygen.
The process is called respiration, and it's how living organisms make energy, explained Brian Lower, assistant professor in the School of Environment and Natural Resources at Ohio State. We use the oxygen we breathe to release energy from our food. But in nature, bacteria don't always have access to oxygen.
"Whether the bacteria are buried in the soil or underwater, they can rely on metals to get the energy they need," Lower said. "It's an ancient form of respiration."
"This kind of respiration is fascinating from an evolutionary standpoint, but we're also interested in how we can use the bacteria to remediate nasty compounds such as uranium, technetium, and chromium."
The last two are byproducts of plutonium. The United States Department of Energy is sponsoring the work in order to uncover new methods for treating waste from nuclear weapons production in the 1960s and '70s.
Shewanella is naturally present in the soil, and can in fact be found at nuclear waste sites such as the Hanford site in the state of Washington, Lower explained.
With better knowledge of the bacterium's abilities, scientis
|Contact: Brian Lower|
Ohio State University