Details zur Publikation

Referenztyp Zeitschriften
DOI / URL Link
Titel (primär) Mechanistic dichotomy in bacterial trichloroethene dechlorination revealed by carbon and chlorine isotope effects
Autor Lihl, C.; Douglas, L.M.; Franke, S.; Pérez-de-Mora, A.; Meyer, A.H.; Daubmeier, M.; Edwards, E.A.; Nijenhuis, I.; Sherwood Lollar, B.; Elsner, M.;
Journal / Serie Environmental Science & Technology
Erscheinungsjahr 2019
Department ISOBIO;
Band/Volume 53
Heft 8
Sprache englisch;
POF III (gesamt) T41;
Supplements https://pubs.acs.org/doi/suppl/10.1021/acs.est.8b06643/suppl_file/es8b06643_si_001.pdf
Abstract Tetrachloroethene (PCE) and trichloroethene (TCE) are significant groundwater contaminants. Microbial reductive dehalogenation at contaminated sites can produce nontoxic ethene but often stops at toxic cis-1,2-dichloroethene (cis-DCE) or vinyl chloride (VC). The magnitude of carbon relative to chlorine isotope effects (as expressed by ΛC/Cl, the slope of δ13C versus δ37Cl regressions) was recently recognized to reveal different reduction mechanisms with vitamin B12 as a model reactant for reductive dehalogenase activity. Large ΛC/Cl values for cis-DCE reflected cob(I)alamin addition followed by protonation, whereas smaller ΛC/Cl values for PCE evidenced cob(I)alamin addition followed by Cl elimination. This study addressed dehalogenation in actual microorganisms and observed identical large ΛC/Cl values for cis-DCE (ΛC/Cl = 10.0 to 17.8) that contrasted with identical smaller ΛC/Cl for TCE and PCE (ΛC/Cl = 2.3 to 3.8). For TCE, the trend of small ΛC/Cl could even be reversed when mixed cultures were precultivated on VC or DCEs and subsequently confronted with TCE (ΛC/Cl = 9.0 to 18.2). This observation provides explicit evidence that substrate adaptation must have selected for reductive dehalogenases with different mechanistic motifs. The patterns of ΛC/Cl are consistent with practically all studies published to date, while the difference in reaction mechanisms offers a potential answer to the long-standing question of why bioremediation frequently stalls at cis-DCE.
ID 21857
dauerhafte UFZ-Verlinkung https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=21857
Lihl, C., Douglas, L.M., Franke, S., Pérez-de-Mora, A., Meyer, A.H., Daubmeier, M., Edwards, E.A., Nijenhuis, I., Sherwood Lollar, B., Elsner, M. (2019):
Mechanistic dichotomy in bacterial trichloroethene dechlorination revealed by carbon and chlorine isotope effects
Environ. Sci. Technol. 53 (8), 4245 - 4254