Pollutant-eating bacteria not so rare

Dioxane, a chemical in wide industrial use, has an enemy in naturally occurring bacteria that remove it from the environment.

Researchers at Rice University have found that these bacteria are more abundant at spill sites than once thought. They are designing tools to help environmental engineers determine the best way to clean up a contaminated site.

A Rice-led team discovered soluble di-iron mono-oxygenase (SDIMO) genes in bacteria thriving in contaminated Alaskan groundwater. The genes produce enzymes that degrade dioxane – specifically, the common form known as 1,4-Dioxane – into harmless substances.

The work may lead to the creation of biomarker-based forensic tools to detect SDIMO-carrying bacteria at dioxane-polluted sites, according to Pedro Alvarez, the George R. Brown Professor and chair of Rice's Civil and Environmental Engineering Department.

Dioxane can get into the ground in accidental spills of 1,1,1-trichloroethane (TCA). Dioxane is used to stabilize TCA, an industrial solvent, and often serves as a solvent itself.

"This contaminant has been flying under the radar," said Alvarez, who also serves on the Environmental Protection Agency's science advisory board. "It is a suspected carcinogen, but for a contaminant to be important or of emerging concern, it has to pose a threat to a large number of people or impact large areas."