G. sulfurreducens, a species of Geobacter bacteria, has an extraordinary ability to remove uranium from contaminated groundwater.
Researchers have been trying to find out how the process works. They suspected that hair-like filaments called pili produced by G. sulfurreducens in certain environments might be the answer.
Earlier this year, researchers had found that the pili on G. sulfurreducens are a type of 'nanowire', because they conduct electricity. The pili help to power the bacterium by transferring electrons produced during the cell's metabolism to external acceptors such as iron, reports Nature.
The species makes use of the pili to offload electrons onto uranium particles, converting them from a form that easily dissolves in water into one that doesn't. The uranium drops out of the water, and it can be more easily removed.
The researchers hope that their findings can help to improve bioremediation - the use of biological organisms to remove pollutants from soil and water.
The study was recently published in Proceedings of the National Academy of Sciences.