Microbes turn nuclear waste into electricity

Posted by Kate Taylor

Researchers at Michigan State University have developed a new strain of a microbe which can efficiently clean up nuclear waste and other toxic metals while generating electricity.

Uranium contamination can be produced at any step in the production of nuclear fuel. And while it's been known for some time that Geobacter can immobilize uranium, the UM team has discovered that the secret to the decontamination process is nanowires - hair-like appendages found on the outside of Geobacters. It's been able to tailor the organism accordingly.

"Geobacter bacteria are tiny micro-organisms that can play a major role in cleaning up polluted sites around the world," says MSU microbiologist Gemma Reguera.

"Our findings clearly identify nanowires as being the primary catalyst for uranium reduction. They are essentially performing nature's version of electroplating with uranium, effectively immobilizing the radioactive material and preventing it from leaching into groundwater."

The nanowires also shield Geobacter and allow the bacteria to thrive in a toxic environment, she added.

In a test, researchers injected acetate into contaminated groundwater. Since this is Geobacter's favorite food, it stimulated the growth of the Geobacter community already in the soil, which in turn, worked to remove the uranium.

Reguera and her team of researchers were able to genetically engineer a Geobacter strain with enhanced nanowire production. The modified version improved the efficiency of the bacteria's ability to immobilize uranium proportionally to the number of nanowires, while subsequently improving its viability as a catalytic cell.

Reguera has filed patents to build on her research. It could lead to the development of microbial fuel cells capable of generating electricity while cleaning up after environmental disasters, she says.