Stable carbon isotope fractionation in chlorinated ethene degradation by bacteria expressing three toluene oxygenases.

Clingenpeel, Scott R. and Moan, Jaina L and McGrath, Danielle M and Hungate, Bruce A. and Watwood, Mary E. (2012) Stable carbon isotope fractionation in chlorinated ethene degradation by bacteria expressing three toluene oxygenases. Frontiers in microbiology, 3. p. 63. ISSN 1664-302X

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Abstract

One difficulty in using bioremediation at a contaminated site is demonstrating that biodegradation is actually occurring in situ. The stable isotope composition of contaminants may help with this, since they can serve as an indicator of biological activity. To use this approach it is necessary to establish how a particular biodegradation pathway affects the isotopic composition of a contaminant. This study examined bacterial strains expressing three aerobic enzymes for their effect on the (13)C/(12)C ratio when degrading both trichloroethene (TCE) and cis-1,2-dichloroethene (c-DCE): toluene 3-monoxygenase, toluene 4-monooxygenase, and toluene 2,3-dioxygenase. We found no significant differences in fractionation among the three enzymes for either compound. Aerobic degradation of c-DCE occurred with low fractionation producing δ(13)C enrichment factors of -0.9 ± 0.5 to -1.2 ± 0.5, in contrast to reported anaerobic degradation δ(13)C enrichment factors of -14.1 to -20.4‰. Aerobic degradation of TCE resulted in δ(13)C enrichment factors of -11.6 ± 4.1 to -14.7 ± 3.0‰ which overlap reported δ(13)C enrichment factors for anaerobic TCE degradation of -2.5 to -13.8‰. The data from this study suggest that stable isotopes could serve as a diagnostic for detecting aerobic biodegradation of TCE by toluene oxygenases at contaminated sites.

Item Type:	Article
Publisher’s Statement:	Creative Commons Attribution License.
ID number or DOI:	10.3389/fmicb.2012.00063
Keywords:	table carbon isotope; trichloroethene; cis-1,2-dichloroethene; toluene oxygenase; aerobic biodegradation
Subjects:	Q Science > QH Natural history Q Science > QR Microbiology
NAU Depositing Author Academic Status:	Faculty/Staff
Department/Unit:	College of Engineering, Forestry, and Natural Science > Biological Sciences Research Centers > Merriam-Powell Center for Environmental Research
Date Deposited:	07 Oct 2015 22:06
URI:	http://openknowledge.nau.edu/id/eprint/669

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