How bacteria "inhale" toxic metals and "exhale" oxygen

Washington, March 17 (ANI): Using a unique combination of microscopes, researchers at Ohio State University in the US were able to see how some common soil bacteria "inhale" toxic metals and "exhale" them in a non-toxic form, namely, oxygen.

The researchers were able to glimpse how the Shewanella oneidensis bacterium breaks down metal to chemically extract oxygen.

The study 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.

The bacteria might one day be used to clean up toxic chemicals left over from nuclear weapons production decades ago.

With better knowledge of the bacterium's abilities, scientists might one day engineer a Shewanella that would remediate nuclear waste more efficiently.

"For instance, if you could enhance this bacterium's ability to reduce uranium by having it make more of these key proteins, that could perhaps be one way to clean up these sites that are contaminated," Lower said.

The danger at such waste sites is that the toxic metals are soluble, and so can leak into the local water supply.

But, these bacteria naturally convert the metals into an insoluble form. Though the metals would remain in place, they would be stable solids instead of unstable liquids.

According to Lower, "Whether the bacteria are buried in the soil or underwater, they can rely on metals to get the energy they need. 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," he added. (ANI)