Mathematical clean up

Cornell researchers hope to learn how certain bacteria that break down pollutants do their job and then to make them more effective in cleaning up toxic wastes.

Bacteria called Dehalococcoides ethenogenes, discovered in Ithaca sewage sludge in 1997 by James Gossett, Cornell professor of civil and environmental engineering, and isolated and studied by Stephen Zinder, Cornell professor of microbiology, are now in wide use to detoxify such carcinogenic chemicals as perchloroethylene (PCE) and trichloroethylene (TCE). They do this by removing chlorine atoms from molecules and leaving less-toxic compounds behind.

But D. ethenogenes strains work well at some sites and not so well at others, and nobody knows for sure why. In fact, very little is understood about how these organisms live and breathe. Normal laboratory procedures haven't provided enough answers, because the bacteria are hard to grow in a petri dish, said Ruth Richardson, Cornell assistant professor of civil and environmental engineering, who is following up on Gossett's and Zinder's work, in continued collaboration with them.