Dual C–Cl isotope fractionation offers potential to assess biodegradation of 1,2-dichloropropane and 1,2,3-trichloropropane by Dehalogenimonas cultures
1,2-dichloropropane (1,2-DCP) and 1,2,3-trichloropropane (1,2,3-TCP) are hazardous chemicals frequently detected in groundwater near agricultural zones due to their historical use in chlorinated fumigant formulations. In this study, we show that the organohalide-respiring bacterium <em style=&quo...
| Authors: | , , , , , |
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| Format: | article |
| Status: | Versión aceptada para publicación |
| Publication Date: | 2024 |
| Country: | España |
| Institution: | Universidad de Barcelona |
| Repository: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/215727 |
| Online Access: | https://hdl.handle.net/2445/215727 |
| Access Level: | Open access |
| Keyword: | Hidrologia d'aigües subterrànies Contaminació de l'aigua Isòtops Groundwater hydrology Water pollution Isotopes |
| Summary: | 1,2-dichloropropane (1,2-DCP) and 1,2,3-trichloropropane (1,2,3-TCP) are hazardous chemicals frequently detected in groundwater near agricultural zones due to their historical use in chlorinated fumigant formulations. In this study, we show that the organohalide-respiring bacterium <em style="color:black">Dehalogenimonas alkenigignens</em><span style="color:black"> strain BRE15M can grow during the dihaloelimination of </span>1,2-DCP and 1,2,3-TCP to propene and allyl chloride, respectively. Our work also provides the first application of dual isotope approach to investigate the anaerobic reductive dechlorination of 1,2-DCP and 1,2,3-TCP. Stable carbon and chlorine isotope fractionation values for 1,2-DCP (Ɛ<sub>C </sub>= -13.6 ± 1.4 ‰ and Ɛ<sub>Cl</sub>= -27.4 ± 5.2 ‰) and 1,2,3-TCP (Ɛ<sub>C </sub>= -3.8 ± 0.6 ‰ and Ɛ<sub>Cl</sub>= -0.8 ± 0.5 ‰) were obtained resulting in distinct dual isotope slopes (Λ<sub>12DCP</sub>= 0.5 ± 0.1, Λ<sub>123TCP</sub>= 4 ± 2). However direct comparison of Λ<sub>C-Cl</sub> among different substrates is not possible and investigation of the C and Cl apparent kinetic isotope effects lead to the hypothesis that <em>concerted </em>dichloroelimination mechanism is more likely for both compounds. In fact, whole cell activity assays using cells suspensions of the <em>Dehalogenimonas</em>-containing culture grown with 1,2-DCP and methyl viologen as electron donor suggest that the same set of reductive dehalogenases was involved in the transformation of 1,2-DCP and 1,2,3-TCP. This study opens the door to the application of isotope techniques for evaluating biodegradation of 1,2-DCP and 1,2,3-TCP, which often co-occur in groundwaters near agricultural fields. |
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