Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published April 1, 1988 | public
Journal Article Open

Trichloroethylene Biodegradation by a Methane-Oxidizing Bacterium


Trichloroethylene (TCE), a common groundwater contaminant, is a suspected carcinogen that is highly resistant to aerobic biodegradation. An aerobic, methane-oxidizing bacterium was isolated that degrades TCE in pure culture at concentrations commonly observed in contaminated groundwater. Strain 46-1, a type I methanotrophic bacterium, degraded TCE if grown on methane or methanol, producing CO2 and water-soluble products. Gas chromatography and 14C radiotracer techniques were used to determine the rate, methane dependence, and mechanism of TCE biodegradation. TCE biodegradation by strain 46-1 appears to be a cometabolic process that occurs when the organism is actively metabolizing a suitable growth substrate such as methane or methanol. It is proposed that TCE biodegradation by methanotrophs occurs by formation of TCE epoxide, which breaks down spontaneously in water to form dichloroacetic and glyoxylic acids and one-carbon products.

Additional Information

Copyright © 1988 by the American Society for Microbiology. Received 5 October 1987/Accepted 6 January 1988 Research was supported by the Oak Ridge National Laboratory Director's Research and Development Fund; by the Y-12 Plant Remedial Action Project, U.S. Department of Energy, under contract DE-AC05-840R21400 with Martin Marietta Energy Systems, Inc.; and by U.S. Department of Energy grant DE-FG02-85ER13386 to M.E. Lidstrom. We thank D.P. Allison, M.C. Rorvik, and T. Fassel for electron micrography and D.M. Genung, K.S. Ironsides, N.M. Ferguson, A.R. Herndon, and T.J. Phelps for technical assistance. H.I. Adler, L.W. Barnthouse, T.L. Donaldson, S.E. Lindberg, G.S. Sayler, G.W. Strandberg, L.E. Toran, V. Tripathi, B.T. Walton, and D.C. White reviewed this manuscript and provided helpful suggestions. John Bartmess of The University of Tennessee and Susan Henry of Stanford University provided thoughtful discussion concerning the mechanism of TCE breakdown.


Files (1.4 MB)
Name Size Download all
1.4 MB Preview Download

Additional details

August 22, 2023
October 16, 2023