US scientists find bacteria that cleans polluted groundwater at uranium ore sites

15 June 2015 (Last Updated June 15th, 2015 18:30)

Scientists at Rutgers University in the US have discovered bacteria that can help to clean polluted groundwater at uranium ore processing sites.

caution: radioactive material, uranium processing, colorado

Scientists at Rutgers University in the US have discovered bacteria that can help to clean polluted groundwater at uranium ore processing sites where nuclear weapons are made.

A team of scientists and collaborators discovered the bacteria in soil at an old uranium ore mill in Rifle, Colorado located almost 200 miles west of Denver, and used during the peak of nuclear weapons production.

Scientists are carrying out a research to see if microorganisms can lock-up uranium that had been released into the soil many years ago, and currently makes well water in the area unsafe to drink.

Scientists have found a bacterium from a common class known as betaproteobacteria that breathes uranium.

The bacterium can drive the chemical reactions that provide life-giving energy by breathing either oxygen or uranium.

School of Environmental and Biological Sciences professor of marine and coastal science Lee Kerkhof said: "After the newly discovered bacteria interact with uranium compounds in water, the uranium becomes immobile.

"It is no longer dissolved in the groundwater and therefore can't contaminate drinking water brought to the surface."

"After the newly discovered bacteria interact with uranium compounds in water, the uranium becomes immobile."

According to Kerkhof, who leads the Rutgers team working with US Department of Energy researchers, the way the reduced uranium produced by the microorganism ultimately behaves in the subsurface environment is yet to be known.

The uranium-breathing bacterium was isolated in the lab when the team recognised that uranium in samples from the Rifle site could be toxic to microorganisms and humans.

By adding the right amounts of dissolved uranium back to the samples where uranium had become immobilised, researchers looked for signs of bacterial activity.

Upon finding the optimal uranium concentrations, the scientists were able to isolate the novel strain.

The research is part of a US Department of Energy programme.


Image: Sign at shuttered uranium mill in Rifle, Colorado, warns onlookers of hazards that remain from Cold War era nuclear weapons production. Photo: courtesy of Bill Gillette, US. National Archives and Records Administration.