Researchers at Michigan State University say the process can be improved and could eventually benefit sites affected by nuclear contamination.
The ability of Geobacter microbes to immobilize uranium has been well documented, but exactly how they achieve the result has been a mystery.
Researchers say they've discovered conductive pili or nanowires -- hair-like appendages found on the outside of Geobacters -- are responsible for the microbes' neutralizing ability, by managing electrical activity.
"Our findings clearly identify nanowires as being the primary catalyst for uranium reduction," MSU microbiologist Gemma Reguera said in a university release. "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 shield Geobacter and allow it to thrive in a toxic environment, she said.
Reguera and colleagues have been able to genetically engineer a Geobacter strain with enhanced nanowire production, which improves its ability to immobilize uranium, MSU said.