Microbiology and Molecular Ecology at Aberdeen, MD
The Microbiology and Molecular Ecology group (NRP/Reston), in cooperation with the USGS Maryland District office, is examining the fate of chlorinated hydrocarbons, formed during munitions production, which contaminate the wetlands and ground water at Aberdeen Proving ground. Changes in the microbial community during the degradation of tetrachloroethane and its breakdown products has been studied in amended microcosms using TRFLP (terminal restriction fragment length polymorphism), a technique that provides a "fingerprint" of community composition. MICROCOSMS (sediments enclosed in a glass bottle) are monitored for changes in chemistry as well as microbial composition.
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Photo shows Michelle M. Lorah, Ph.D. of the USGS MD District office (June 2000) holding a freshly extracted peeper (piezometer) used to analyze the composition of sediment pore waters |  |
Michelle M. Lorah and Dave Kempisky doing field analyses during June 2000 piezometer sampling |
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The field personnel must wear HAZMAT suits because of the highly toxic nature of chlorinated hydrocarbons |
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Power Point Presentations (these may not work in all browsers)
"DNA fingerprints" in Microcosm Sediment show community changes over time
Links
Aberdeen
Publication - WRIR 03-4119
Preliminary Assessment of
Microbial Communities and
Biodegradation of Chlorinated Volatile Organic Compounds in Wetlands at
Cluster
13, Lauderick Creek Area, Aberdeen Proving Ground, Maryland
By Michelle
M. Lorah, Mary A. Voytek, and Tracey A. Spencer.
Anaerobic Degradation of 1,1,2,2-Tetrachloroethane and Association with Microbial Communities in a Freshwater Tidal Wetland, Aberdeen Proving Ground, Maryland: Laboratory Experiments and Comparisons to Field Data.
By Michelle M. Lorah, Mary A. Voytek, Julie D. Kirshtein, and Elizabeth J. (Phillips) Jones
Jones, E.J.P., Voytek, M.A., Lorah, M.M., and Kirshtein, J.D., 2006, Characterization of a microbial consortium capable of rapid and simultaneous dechlorination of 1,1,2,2-tetrachloroethane and chlorinated ethane and ethene intermediates: Bioremediation Journal, v. 10, p. 153-168. (on-line abstract of journal article)
Microbial Consortium that dechlorinates 1,1,2,2 Tetrachloroethane and all its daughter products
This consortium of bacteria and methanogens has been developed in our U.S. Geological Survey lab at Reston, VA. This consortium, in development since 2002, was started using Aberdeen sediment, and enriched and grown in a medium with chlorinated compounds as terminal electron acceptors. The culture was scaled up by Geosyntec in Guelph, Canada for use in a field test at Aberdeen Proving Ground. The microbial consortium was deployed in a permeable layer of soil materials that was constructed over a "hot spot" of chlorinated compound discharge in the wetland. The field test will be monitored for its effectiveness in removing chlorinated compounds and preventing the release of these toxic compounds in the waters of West Branch Canal Creek, a tidal wetland. A report describing the development and composition of this exciting new consortium is in preparation.
right: construction of the biomat in the field test for treatment of chlorinated compounds. |
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The microbes were sprayed into a layer of the biomat. Testing has shown that the microbes recover rapidly from aerobic exposure. The dechlorination process is anaerobic resulting in more reduced products such as ethene and ethane. |
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Photos
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