Previous Article | Next Article ![]()
Applied and Environmental Microbiology, July 1999, p. 3108-3113, Vol. 65, No. 7
Section of Microbiology, Cornell University,
Ithaca, New York 14853-8101
Received 23 October 1998/Accepted 27 April 1999
"Dehalococcoides ethenogenes" 195 can reductively
dechlorinate tetrachloroethene (PCE) completely to ethene (ETH). When
PCE-grown strain 195 was transferred (2% [vol/vol] inoculum) into
growth medium amended with trichloroethene (TCE),
cis-dichloroethene (DCE), 1,1-DCE, or 1,2-dichloroethane
(DCA) as an electron acceptor, these chlorinated compounds were
consumed at increasing rates over time, which indicated that growth
occurred. Moreover, the number of cells increased when TCE, 1,1-DCE, or
DCA was present. PCE, TCE, 1,1-DCE, and cis-DCE were
converted mainly to vinyl chloride (VC) and then to ETH, while DCA was
converted to ca. 99% ETH and 1% VC. cis-DCE was used at
lower rates than PCE, TCE, 1,1-DCE, or DCA was used. When PCE-grown
cultures were transferred to media containing VC or
trans-DCE, products accumulated slowly, and there was no
increase in the rate, which indicated that these two compounds did not
support growth. When the intermediates in PCE dechlorination by strain
195 were monitored, TCE was detected first, followed by
cis-DCE. After a lag, VC, 1,1-DCE, and
trans-DCE accumulated, which is consistent with the
hypothesis that cis-DCE is the precursor of these
compounds. Both cis-DCE and 1,1-DCE were eventually
consumed, and both of these compounds could be considered intermediates
in PCE dechlorination, whereas the small amount of
trans-DCE that was produced persisted. Cultures grown on
TCE, 1,1-DCE, or DCA could immediately dechlorinate PCE, which indicated that PCE reductive dehalogenase activity was constitutive when these electron acceptors were used.
0099-2240/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.
Reductive Dechlorination of Chlorinated Ethenes and
1,2-Dichloroethane by "Dehalococcoides
ethenogenes" 195

*
Corresponding author. Mailing address: Section of
Microbiology, Wing Hall, Cornell University, Ithaca, NY 14853-8101. Phone: (607) 255-2415. Fax: (607) 255-3904. E-mail:
shz1{at}cornell.edu.
Present address: McKinsey & Company, 28010 Madrid, Spain.
This article has been cited by other articles:
| J. Bacteriol. | Microbiol. Mol. Biol. Rev. | Eukaryot. Cell | All ASM Journals |
|---|