Trichloroethylene (TCE) and tetrachloroethylene (PCE) are degraded by BAV1 microbe
In 2003, researchers at Georgia Tech recently discovered a microbe, which they named BAV1) capable of degrading TCE and PCE, two of the halogenated solvents most frequently targeted for bioremediation, into the harmless byproducts of ethene and inorganic chloride. Head researcher Frank Loeffler suspects that the bacteria originally evolved consuming the low levels of naturally occurring chlorinated compounds; however he discovered the bacteria near a dry cleaning facility that had dumped PCE for many years. In sites where PCE and TCE are dumped BAV1 is usually found in levels too low to make a significant remediation impact. However, researchers were able to greatly augment BAV1’s natural bioremediation potential by employing two different bioremediation techniques: biostimulation and bioaugmentation. Biostimulation involved adding lactate and nutrients to the contaminated plot to stimulate the growth of BAV1. Bioaugmentation, involved adding a culture containing high numbers of BAV1 along with the nutrients. Both strategies proved successful, and the bioaugmentation technique was successful in remediating a contaminated water supply in six weeks (biostimulation takes longer).
BAV1 is currently marketed by the bioremediation technology company Regenisis under the product name Bio-Dechlor Inoculum. Bio-Dechlor Inoculum contains a suite of Dehalococcoide species that perform dehalogenation of contaminants in situ. BAV1 plays a crucial role because it is able to degrade recalcitrant intermediate compounds (such as vinyl chloride) directly. All other species of Dehalococcoide cometabolize vinyl chloride, a much slower process, but BAV1 is able to use vinyl chloride as a growth substrate and electron acceptor. Bio-Dechlor Inoculum has proven successful at remediating halogenated solvent contaminated sites.
Sources: Kahn, 2003 and www.regenisis.com
Phytoremediation Studies from the USGS Toxic Substances Hydrology Program
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