A new variety of microbe capable of eating waste materials at nuclear sites and rendering them less harmful has been developed by scientists in the United States.

The modified microbe, based on Deinococcus radiodurans, can dispose of the toxic heavy metals and organic chemicals commonly found at weapons production sites where normal bacteria cannot survive.

Its development could herald a breakthrough in the expensive and difficult clean-up process of removing radioactive pollution from around nuclear dumping sites.

Most of the waste generated by the world's nuclear weapons industries between 1945 and 1986 was dumped in the ground.

Many of the sites are now disintegrating, leading to the contamination of soil and groundwater and running up an estimated clean-up bill of $300bn in the US alone.

Transferring genes

It is hoped the new superbug, which works in the laboratory but has yet to be tested in the field, will fare better than other pollution-eating bacteria which have died at nuclear sites due to radiation exposure.

Researchers at the Uniformed Services University of the Health Sciences in Maryland created the microbe by transferring genes from one bacterium into the existing radiation-resilient Deinococcus radiodurans bug.

According to the journal Nature, the new bug can convert radioactive mercury compounds into the less harmful elemental form and has the ability to break down organic solvents.

Future efforts are likely to attempt to integrate several other bioremediation functions into the bacterium, creating a kind of superbug capable of making a variety of types of waste less hazardous.