Chlorinated chemicals perform a host of societally useful functions, but they also have a dark side. Once their use life has ended, such agents often become environmental contaminants, sometimes resistant to bioremediation.
In a series of new studies, Anca Delgado, a researcher at Arizona State University's Biodesign Institute, examines unique groups of microorganisms, capable of converting hazardous chlorinated chemicals like trichloroetheene (TCE) into ethene, a benign end product of microbial biodegradation.
The research was conducted as part of her doctorate work under the guidance of associate professor Rosa Krajmalnik-Brown at Biodesign's Swette Center for Environmental Biotechnology. Results of the most recent of three studies appear in the current, advanced online edition of the journal PLOS ONE.
The new studies explore the metabolic activities of a group of microbes known as Dehalococcoides, and propose strategies to improve their effectiveness for environmental cleanup projects involving chlorinated chemicals.
"Dehalococcoides have been officially on the scientific map since 1997," Delgado says, noting that they remain the only microorganisms of their kind, and therefore of great importance for bioremediation. "In close to 20 years we have not discovered other bacteria that can perform reductive dechlorination of chemicals like TCE all the way to ethene."
Trichloroethene focus of the current studies is one of the most ubiquitous chlorinated chemicals. Approximately 60 percent of the U.S. National Priorities List Superfund sites and roughly 20 percent of the national groundwater sources are contaminated with chlorinated solvents, such as TCE. TCE is a sweet-smelling, non-flammable liquid halocarbon that was widely used in the past century because of its properties as an effective industrial solvent, with applications ranging from dry cleaning to the cleaning and degreasing of an enormo
|Contact: Joseph Caspermeyer|
Arizona State University