Genome hope for clean-up

Chlorinated compounds are notoriously difficult to clean up, and pollution from dry-cleaning fluids and silicon chip production present a particular challenge for waste treatment companies.

Research from The Institute for Genomic Research (TIGR) in Rockville, Maryland, has found what could be an important tool for this: a team led by Rekha Seshadri has deciphered the genome sequence of the only microbe known to degrade tetrachloroethylene and trichloroethylene.

'Because chlorinated solvents have polluted so many water sources, there is a pressing need for new techniques to clean up such pollutants,' says John Heidelberg, an associate investigator at TIGR and a member of the research team.

The microbe studied by the team, Dehalococcides ethenogenes, 'breathes' chlorinated solvents, converting them into non-toxic ethene. It is already in use as a clean-up agent, but the genome sequence could provide valuable information for remediation applications.

The researchers identified genes for 19 different enzymes known as reductive dehalogenases, which remove chlorine from the solvents.

In the long term, the genome could help in designing more effective processes for removing chorinated solvents and compounds, such as vinyl chloride.