Bioremediating chloroethene contamination

The widely used chlorinated solvents tetrachloroethene (PCE) and trichloroethene (TCE) are among the most abundant groundwater pollutants. Once in the environment, both biogeochemical- and microbial-driven processes transform these compounds into other highly toxic and environmentally persistent substances, such as dichloroethenes and the carcinogenic vinyl chloride. In the July 3 Nature, Jianzhong He and colleagues at the Georgia Institute of Technology isolate a novel bacterium that metabolizes chloroethene-derived contaminants, converting them in harmless products (Nature, 424:62-65, July 3, 2003).

Jianzhong et al. analyzed a microcosm obtained from chloroethene-impacted sites, a microbial culture able of dechlorinating PCE to nontoxic ethene. This led to the isolation of a novel, disc-shaped organism called BAV1 that utilized dichloroethenes and vinyl chloride as growth-supporting electron acceptors under strictly anaerobic conditions, transforming the toxins to ethene and inorganic chloride. Reductive dechlorination was dependent on hydrogen as electron donor. They then used 16S rRNA gene-based tools and ascertained ...