The Next Big Thing #3: Eats Dry-Cleaning Fluid for Breakfast
Posted by Richard Conniff on December 27, 2013
It sometimes seems as if the entire world is irreversibly contaminated with industrial chemicals. Groundwater, for instance, is widely tainted with the industrial solvent trichloroethylene (TCE) and the dry-cleaning fluid tetrachloroethylene (PCE). Microbes may be our best hope for cleaning up the mess. When researchers first discovered in the 1990s that chlorine-hungry bacterial species in the Dehalococcoides genus could break TCE and PCE down into harmless ethane—the same gas used to ripen fruit—it sounded too good to be true. In the first test case, researchers injected a beer-keg’s worth of bacterial culture into the heavily contaminated groundwater beneath Kelly Air Force Base in Texas. Monitoring of wells showed the progress of the bacteria as they quickly spread through the polluted area—and after just 115 days, the PCE problem there was fixed. Dehalococcoides treatment, combined with a little molasses or lactose as a feedstock, is now a standard commercial cleanup technology. Other researchers are also working on bacterial methods to clean up mercury and other heavy metals, mining wastes, and 500 million gallons of North American groundwater contaminated with uranium.