Carbon isotope fractionation during aerobic biodegradation of trichloroethene by Burkholderia cepacia G4: a tool to map degradation mechanisms

Barth, J.A.C., Slater, G., Schuth, C., Bill, M., Downey, A., Larkin, M. and Kalin, R.M. (2002) Carbon isotope fractionation during aerobic biodegradation of trichloroethene by Burkholderia cepacia G4: a tool to map degradation mechanisms. Applied and Environmental Microbiology, 68(4), pp. 1728-1734. (doi: 10.1128/AEM.68.4.1728-1734.2002)

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Publisher's URL: http://dx.doi.org/10.1128/AEM.68.4.1728-1734.2002

Abstract

The strain Burkholderia cepacia G4 aerobically mineralized trichloroethene (TCE) to CO2 over a time period of similar to20 h. Three biodegradation experiments were conducted with different bacterial optical densities at 540 nm (OD(540)s) in order to test whether isotope fractionation was consistent. The resulting TCE degradation was 93, 83.8, and 57.2% (i.e., 7.0, 16.2, and 42.8% TCE remaining) at OD(540)s of 2.0, 1.1, and 0.6, respectively. ODs also correlated linearly with zero-order degradation rates (1.99, 1.11, and 0.64 mumol h(-1)). While initial nonequilibrium mass losses of TCE produced only minor carbon isotope shifts (expressed in per mille delta C- 13(VPDB)), they were 57.2, 39.6, and 17.0parts per thousand between the initial and final TCE levels for the three experiments, in decreasing order of their OD(540)s. Despite these strong isotope shifts, we found a largely uniform isotope fractionation. The latter is expressed with a Rayleigh enrichment factor, E, and was -18.2 when all experiments were grouped to a common point of 42.8% TCE remaining. Although, decreases of epsilon to -20.7 were observed near complete degradation, our enrichment factors were significantly more negative than those reported for anaerobic dehalogenation of TCE. This indicates typical isotope fractionation for specific enzymatic mechanisms that can help to differentiate between degradation pathways.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:UNSPECIFIED
Authors: Barth, J.A.C., Slater, G., Schuth, C., Bill, M., Downey, A., Larkin, M., and Kalin, R.M.
Subjects:Q Science > QR Microbiology
G Geography. Anthropology. Recreation > GE Environmental Sciences
College/School:College of Science and Engineering > Scottish Universities Environmental Research Centre
Journal Name:Applied and Environmental Microbiology
Publisher:American Society for Microbiology
ISSN:0099-2240
ISSN (Online):1098-5336
Copyright Holders:© Copyright American Society for Microbiology.
First Published:First published in Applied and Environmental Microbiology 68(4):1728-1734
Publisher Policy:Reproduced in accordance with the copyright policy of the publisher

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