Narrator: This is Science Today. Biochemical engineers at the University of California, Irvine are working to clean up contaminated sites by genetically engineering bacteria to degrade toxic compounds. Dr. Thomas Wood's laboratory at UC Irvine, is focusing on the bacteria near plant roots.

Wood: We're trying to encourage the bacteria to degrade trichloroethylene into carbon dioxide, which is chloride ions by giving these bacteria an additional gene that allows them to degrade this compound.

Narrator: And with trichloroethylene, a faster process is crucial since slow degradation results in a compound which is even more toxic.

Wood: What we're trying to do is prevent the trichloroethylene - the pollutant - from getting into the groundwater. Now, over the world, there are wells that have been contaminated and decommissioned because they have trichloroethylene and there are estimates that if you drink over your lifetime one part per million of trichloroethylene, about thirty-two people out of every hundred thousand would get cancer. So it's not something you want to drink routinely.

Narrator: For Science Today, I'm Larissa Branin.