1
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Palau J, Trueba-Santiso A, Yu R, Mortan SH, Shouakar-Stash O, Freedman DL, Wasmund K, Hunkeler D, Marco-Urrea E, Rosell M. Dual C-Br Isotope Fractionation Indicates Distinct Reductive Dehalogenation Mechanisms of 1,2-Dibromoethane in Dehalococcoides- and Dehalogenimonas-Containing Cultures. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:1949-1958. [PMID: 36700533 PMCID: PMC9910042 DOI: 10.1021/acs.est.2c07137] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 12/03/2022] [Accepted: 12/28/2022] [Indexed: 06/17/2023]
Abstract
Brominated organic compounds such as 1,2-dibromoethane (1,2-DBA) are highly toxic groundwater contaminants. Multi-element compound-specific isotope analysis bears the potential to elucidate the biodegradation pathways of 1,2-DBA in the environment, which is crucial information to assess its fate in contaminated sites. This study investigates for the first time dual C-Br isotope fractionation during in vivo biodegradation of 1,2-DBA by two anaerobic enrichment cultures containing organohalide-respiring bacteria (i.e., either Dehalococcoides or Dehalogenimonas). Different εbulkC values (-1.8 ± 0.2 and -19.2 ± 3.5‰, respectively) were obtained, whereas their respective εbulkBr values were lower and similar to each other (-1.22 ± 0.08 and -1.2 ± 0.5‰), leading to distinctly different trends (ΛC-Br = Δδ13C/Δδ81Br ≈ εbulkC/εbulkBr) in a dual C-Br isotope plot (1.4 ± 0.2 and 12 ± 4, respectively). These results suggest the occurrence of different underlying reaction mechanisms during enzymatic 1,2-DBA transformation, that is, concerted dihaloelimination and nucleophilic substitution (SN2-reaction). The strongly pathway-dependent ΛC-Br values illustrate the potential of this approach to elucidate the reaction mechanism of 1,2-DBA in the field and to select appropriate εbulkC values for quantification of biodegradation. The results of this study provide valuable information for future biodegradation studies of 1,2-DBA in contaminated sites.
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Affiliation(s)
- Jordi Palau
- Grup
MAiMA, SGR Mineralogia Aplicada, Geoquímica i Geomicrobiologia,
Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat
de Ciències de la Terra, Institut de Recerca de l’Aigua
(IdRA), Universitat de Barcelona (UB), Martí Franquès s/n, Barcelona08028, Spain
| | - Alba Trueba-Santiso
- Departament
d’Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona (UAB), Carrer de les Sitges s/n, Bellaterra08193, Spain
| | - Rong Yu
- Synterra
Corporation, Greenville, South Carolina29601, United States
| | - Siti Hatijah Mortan
- Departament
d’Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona (UAB), Carrer de les Sitges s/n, Bellaterra08193, Spain
| | | | - David L. Freedman
- Department
of Environmental Engineering and Earth Sciences, Clemson University, Clemson, South Carolina29634, United States
| | - Kenneth Wasmund
- Division
of Microbial Ecology, Centre for Microbiology and Environmental Systems
Science, University of Vienna, ViennaA-1030, Austria
| | - Daniel Hunkeler
- Centre
for Hydrogeology and Geothermics, University
of Neuchâtel, Neuchâtel2000, Switzerland
| | - Ernest Marco-Urrea
- Departament
d’Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona (UAB), Carrer de les Sitges s/n, Bellaterra08193, Spain
| | - Monica Rosell
- Grup
MAiMA, SGR Mineralogia Aplicada, Geoquímica i Geomicrobiologia,
Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat
de Ciències de la Terra, Institut de Recerca de l’Aigua
(IdRA), Universitat de Barcelona (UB), Martí Franquès s/n, Barcelona08028, Spain
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2
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Ouyang WY, Kümmel S, Adrian L, Zhu YG, Richnow HH. Carbon and hydrogen stable isotope fractionation of sulfamethoxazole during anaerobic transformation catalyzed by Desulfovibrio vulgaris Hildenborough. CHEMOSPHERE 2023; 311:136923. [PMID: 36349587 DOI: 10.1016/j.chemosphere.2022.136923] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 10/11/2022] [Accepted: 10/16/2022] [Indexed: 06/16/2023]
Abstract
The fate of antibiotics in aquatic environments is of high concern and approaches are needed to assess the transformation of antibiotics in wastewater treatment plants. Here we used the model organism Desulfovibrio vulgaris Hildenborough to analyze compound specific isotope fractionation associated with anaerobic transformation of the antibiotic sulfamethoxazole (SMX). The results show that the rearrangement of the isoxazole ring in SMX is leading to significant carbon and hydrogen isotopic fractionation (εC = -5.8 ± 0.7‰, εH = -34 ± 9‰) during anaerobic transformation. The observed carbon isotopic fractionation is significantly higher than the values reported for aerobic degradation (εC = -0.6 ± 0.1‰) or abiotic reactions (εC = -0.8 to -4.8‰ for photolysis, εC = -0.8 to -2.2‰ for advanced oxidation). This indicates that carbon isotope fractionation can be used as a parameter to differentiate reaction mechanisms of SMX transformation. The corresponding apparent kinetic isotope effect (AKIEC) for anaerobic transformation of SMX was 1.029 ± 0.003, suggesting that the mechanism for anaerobic transformation is distinct from the mechanism reported for microbial aerobic degradation (AKIEC = 1.006 ± 0.001). In addition, dual-element (C-H) isotope analysis of SMX was performed in the present study, which was achieved by utilizing gas chromatography (GC) as the separation method instead of routine liquid chromatography. This dual-element isotope analysis resulted in a Λ value of 4.5 ± 2.2. Overall, compound specific isotope analysis can be a feasible tool to monitor the mitigation of SMX in wastewater treatment plants.
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Affiliation(s)
- Wei-Ying Ouyang
- Helmholtz Centre for Environmental Research - UFZ, Isotope Biogeochemistry, Leipzig, Germany; Chair of Geobiotechnology, Technische Universität Berlin, Berlin, Germany
| | - Steffen Kümmel
- Helmholtz Centre for Environmental Research - UFZ, Isotope Biogeochemistry, Leipzig, Germany
| | - Lorenz Adrian
- Chair of Geobiotechnology, Technische Universität Berlin, Berlin, Germany; Helmholtz Centre for Environmental Research - UFZ, Environmental Biotechnology, Leipzig, Germany
| | - Yong-Guan Zhu
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, China
| | - Hans H Richnow
- Helmholtz Centre for Environmental Research - UFZ, Isotope Biogeochemistry, Leipzig, Germany; Isodetect GmbH, Leipzig, Germany.
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3
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Phillips E, Bulka O, Picott K, Kümmel S, Edwards E, Nijenhuis I, Gehre M, Dworatzek S, Webb J, Lollar BS. Investigation of Active Site Amino Acid Influence on Carbon and Chlorine Isotope Fractionation during Reductive Dechlorination. FEMS Microbiol Ecol 2022; 98:6608266. [PMID: 35700008 DOI: 10.1093/femsec/fiac072] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 05/23/2022] [Accepted: 06/09/2022] [Indexed: 11/13/2022] Open
Abstract
Reductive dehalogenases (RDases) are corrinoid-dependent enzymes that reductively dehalogenate organohalides in respiratory processes. By comparing isotope effects in biotically-catalyzed reactions to reference experiments with abiotic corrinoid-catalysts, compound-specific isotope analysis (CSIA) has been shown to yield valuable insights into enzyme mechanisms and kinetics, including RDases. Here, we report isotopic fractionation (ε) during biotransformation of chloroform (CF) for carbon (εC = -1.52 ± 0.34‰) and chlorine (εCl = -1.84 ± 0.19‰), corresponding to a ΛC/Cl value of 1.13 ± 0.35. These results are highly suppressed compared to isotope effects observed both during CF biotransformation by another organism with a highly similar RDase (> 95% sequence identity) at the amino acid level, and to those observed during abiotic dehalogenation of CF. Amino acid differences occur at four locations within the two different RDases' active sites, and this study examines whether these differences potentially affect the observed εC, εCl, and ΛC/Cl. Structural protein models approximating the locations of the residues elucidate possible controls on reaction mechanisms and/or substrate binding efficiency. These four locations are not conserved among other chloroalkane reducing RDases with high amino acid similarity (> 90%), suggesting that these locations may be important in determining isotope fractionation within this homologous group of RDases.
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Affiliation(s)
- Elizabeth Phillips
- Department of Earth Sciences, University of Toronto, 22 Ursula Franklin Street, Toronto, Ontario M5S 3B1, Canada
| | - Olivia Bulka
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada
| | - Katherine Picott
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada
| | - Steffen Kümmel
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Elizabeth Edwards
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario M5S 3E5, Canada
| | - Ivonne Nijenhuis
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Matthias Gehre
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
| | | | | | - Barbara Sherwood Lollar
- Department of Earth Sciences, University of Toronto, 22 Ursula Franklin Street, Toronto, Ontario M5S 3B1, Canada
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Chen S, Ma L, Wang Y. Kinetic isotope effects of C and N indicate different transformation mechanisms between atzA- and trzN-harboring strains in dechlorination of atrazine. Biodegradation 2022; 33:207-221. [PMID: 35257297 DOI: 10.1007/s10532-022-09977-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 02/18/2022] [Indexed: 11/02/2022]
Abstract
Compound-specific stable isotope analysis provides an alternative method to insight into the biotransformation mechanisms of diffuse organic pollutants in the environment, e.g., the endocrine disruptor herbicide atrazine. Biotic hydrolysis process catalyzed by chlorohydrolase AtzA and TrzN plays an important role in the detoxification of atrazine, while the catalytic mechanism of AtzA is still speculative. To investigate the catalytic mechanism of AtzA and answer whether both enzymes catalyze hydrolytic dechlorination of atrazine by the same mechanism, in this study, apparent kinetic isotope effects (AKIE) for carbon and nitrogen were observed by three atzA-harboring bacterial isolates and their membrane-free extracts. The AKIEs obtained from atzA-harboring bacterial isolates (AKIEC = 1.021 ± 0.010, AKIEN = 0.992 ± 0.003) were statistically different from that of trzN-harboring strains (AKIEC = 1.040 ± 0.006, AKIEN = 0.983 ± 0.006), confirming the different activation mechanisms of atrazine preceding to nucleophilic aromatic substitution of Cl atom in actual enzymatic reaction catalyzed by AtzA and TrzN, despite the limitation of variable dual-element isotope plots. The lower degree of normal carbon and inverse nitrogen isotope fractionation observed from atzA-harboring strains, suggesting AtzA catalyzing hydrolytic dechlorination of atrazine by coordination of Cl and one aromatic N to the Fe2+ drawing electron density from carbon-chlorine bond that facilitating the nucleophilic attack, rather than in TrzN case that protonation of aromatic N increasing nucleophilic substitution of Cl atom. This study suggests considering the potential influences of phylogenetic diversity of bacterial isolates and evolution of enzymes on the applications of CSIA method in future study.
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Affiliation(s)
- Songsong Chen
- College of Architecture and Urban Planning, Tongji University, 1239, Siping Road, Shanghai, 200092, People's Republic of China
| | - Limin Ma
- College of Environmental Science and Engineering, Tongji University, 1239, Siping Road, Shanghai, 200092, People's Republic of China.
| | - Yuncai Wang
- College of Architecture and Urban Planning, Tongji University, 1239, Siping Road, Shanghai, 200092, People's Republic of China.
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5
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Soder-Walz JM, Torrentó C, Algora C, Wasmund K, Cortés P, Soler A, Vicent T, Rosell M, Marco-Urrea E. Trichloromethane dechlorination by a novel Dehalobacter sp. strain 8M reveals a third contrasting C and Cl isotope fractionation pattern within this genus. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 813:152659. [PMID: 34954170 DOI: 10.1016/j.scitotenv.2021.152659] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 12/17/2021] [Accepted: 12/20/2021] [Indexed: 06/14/2023]
Abstract
Trichloromethane (TCM) is a pollutant frequently detected in contaminated aquifers, and only four bacterial strains are known to respire it. Here, we obtained a novel Dehalobacter strain capable of transforming TCM to dichloromethane, which was denominated Dehalobacter sp. strain 8M. Besides TCM, strain 8M also completely transformed 1,1,2-trichloroethane to vinyl chloride and 1,2-dichloroethane. Quantitative PCR analysis for the 16S rRNA genes confirmed growth of Dehalobacter with TCM and 1,1,2-trichloroethane as electron acceptors. Carbon and chlorine isotope fractionation during TCM transformation was studied in cultured cells and in enzymatic assays with cell suspensions and crude protein extracts. TCM transformation in the three studied systems resulted in small but significant carbon (εC = -2.7 ± 0.1‰ for respiring cells, -3.1 ± 0.1‰ for cell suspensions, and - 4.1 ± 0.5‰ for crude protein extracts) and chlorine (εCl = -0.9 ± 0.1‰, -1.1 ± 0.1‰, and - 1.2 ± 0.2‰, respectively) isotope fractionation. A characteristic and consistent dual CCl isotope fractionation pattern was observed for the three systems (combined ΛC/Cl = 2.8 ± 0.3). This ΛC/Cl differed significantly from previously reported values for anaerobic dechlorination of TCM by the corrinoid cofactor vitamin B12 and other Dehalobacter strains. These findings widen our knowledge on the existence of different enzyme binding mechanisms underlying TCM-dechlorination within the genus Dehalobacter and demonstrates that dual isotope analysis could be a feasible tool to differentiate TCM degraders at field studies.
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Affiliation(s)
- Jesica M Soder-Walz
- Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona (UAB), Carrer de les Sitges s/n, Bellaterra, Spain
| | - Clara Torrentó
- Grup MAiMA, Mineralogia Aplicada, Geoquímica i Geomicrobiologia, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Institut de Recerca de l'Aigua (IdRA), Universitat de Barcelona (UB), c/ Martí Franquès s/n, 08028 Barcelona, Spain
| | - Camelia Algora
- Laboratory of Environmental Microbiology, Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 14220, Praha 4, Czech Republic
| | - Kenneth Wasmund
- Division of Microbial Ecology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna 1010, Austria
| | - Pilar Cortés
- Departament de Genètica i de Microbiologia, Facultat de BioCiències, Universitat Autònoma de Barcelona, 08193, Bellaterra, Barcelona, Spain
| | - Albert Soler
- Grup MAiMA, Mineralogia Aplicada, Geoquímica i Geomicrobiologia, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Institut de Recerca de l'Aigua (IdRA), Universitat de Barcelona (UB), c/ Martí Franquès s/n, 08028 Barcelona, Spain
| | - Teresa Vicent
- Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona (UAB), Carrer de les Sitges s/n, Bellaterra, Spain
| | - Mònica Rosell
- Grup MAiMA, Mineralogia Aplicada, Geoquímica i Geomicrobiologia, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Institut de Recerca de l'Aigua (IdRA), Universitat de Barcelona (UB), c/ Martí Franquès s/n, 08028 Barcelona, Spain.
| | - Ernest Marco-Urrea
- Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona (UAB), Carrer de les Sitges s/n, Bellaterra, Spain
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6
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Chen P, Liu H, Xing Z, Wang Y, Zhang X, Zhao T, Zhang Y. Cometabolic degradation mechanism and microbial network response of methanotrophic consortia to chlorinated hydrocarbon solvents. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 230:113110. [PMID: 34971998 DOI: 10.1016/j.ecoenv.2021.113110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 12/17/2021] [Accepted: 12/18/2021] [Indexed: 06/14/2023]
Abstract
The cometabolism mechanism of chlorinated hydrocarbon solvents (CHSs) in mixed consortia remains largely unknown. CHS biodegradation characteristics and microbial networks in methanotrophic consortia were studied for the first time. The results showed that all CHSs can efficiently be degraded via cometabolism with a maximum degradation rate of 4.8 mg/(h·gcell). Chloroalkane and chloroethylene were more easily degraded than chlorobenzenes by methanotrophic consortia, especially nonfully chlorinated aliphatic hydrocarbons, which were converted to Cl- with a production rate of 0.29-0.36 mg/(h·gcell). In addition, the microecological response results indicated that Methylocystaceae (49.0%), Methylomonas (65.3%) and Methylosarcina (41.9%) may be the major functional degraders in methanotrophic consortia. Furthermore, the results of the microbial correlation network suggested that interactive relationships constructed by type I methanotrophs and heterotrophs determined biodegradability. Additionally, PICRUSt analysis showed that CHSs could increase the relative abundance of CHS degradation genes and reduce the relative abundance of methane oxidation genes, which was in good agreement with the experimental results.
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Affiliation(s)
- Peipei Chen
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, China
| | - Hao Liu
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, China
| | - Zhilin Xing
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, China.
| | - Yongqiong Wang
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, China
| | - Xiaoping Zhang
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, China
| | - Tiantao Zhao
- School of Chemistry and Chemical Engineering, Chongqing University of Technology, Chongqing 400054, China
| | - Yunru Zhang
- School of Pharmacy and Bioengineering, Chongqing University of Technology, Chongqing 400054, China
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7
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Wang G, Liu Y, Wang X, Dong X, Jiang N, Wang H. Application of dual carbon-bromine stable isotope analysis to characterize anaerobic micro-degradation mechanisms of PBDEs in wetland bottom-water. WATER RESEARCH 2022; 208:117854. [PMID: 34800854 DOI: 10.1016/j.watres.2021.117854] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Revised: 11/05/2021] [Accepted: 11/06/2021] [Indexed: 06/13/2023]
Abstract
Polybrominated diphenyl ethers (PBDEs), one kind of persistent organic pollutants, were widely detected in coastal wetlands. Microbial reductive debromination is one of the most important attenuation processes for PBDEs in anaerobic environment, whereas the underlying reaction mechanisms remain elusive. Dual-element stable isotope analysis was recently recognized to distinguish different reaction mechanism for degradation of organic pollutants. In this study, the dual carbon-bromine isotope effects associated with the anaerobic microbial degradation were first investigated to characterize the reaction mechanisms for BDE-47 and BDE-153. Presence of lower brominated congeners indicated stepwise debromination as the main degradation pathway, with the preferential removal of bromine in para position > meta/ortho position. The pronounced isotope fractionation was observed for both carbon and bromine, with similar carbon (εC) and bromine isotope enrichment factor (εBr) between BDE-47 (εC = -5.98‰, εBr = -2.44‰) and BDE-153 (εC = -5.57‰, εBr = -2.06‰) during the microbial degradation. Compared to εC and εBr, the correlation of carbon and isotope effects (ΛC/Br = Δδ81Br/Δδ13C) was almost the same between BDE-47 (0.436) and BDE-153 (0.435), indicating the similar reaction mechanism. The calculated carbon and bromine apparent kinetic isotope effects (AKIEC and AKIEBr) were 1.0773 and 1.0098 for BDE-47 and 1.0716 and 1.0125 for BDE-153, within range reported for degradation of halogenated compounds following nucleophilic substitution. Combination analysis of degradation products, ΛC/Br and AKIE, all the results pointed to that the anaerobic reductive debromination of BDE-47 and BDE-153 followed the nucleophilic aromatic substitution, with the addition of cofactor to the benzene ring concomitant with dissociation of carbon-bromine bond via the inner-sphere electron transfer, and the cleavage of C-Br bond was the rate-determining step. This study contributed to the development of dual carbon-bromine isotope analysis as a robust approach to probe the fate of PBDEs in contaminated sites.
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Affiliation(s)
- Guoguang Wang
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China
| | - Yu Liu
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China; Environmental Information Institute, Dalian Maritime University, Dalian 116026, China.
| | - Xu Wang
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China
| | - Xu Dong
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China
| | - Na Jiang
- College of Environmental Science and Engineering, Dalian Maritime University, Dalian 116026, China
| | - Haixia Wang
- Navigation College, Dalian Maritime University, Dalian 116026, China
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8
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Gilevska T, Sullivan Ojeda A, Kümmel S, Gehre M, Seger E, West K, Morgan SA, Mack EE, Sherwood Lollar B. Multi-element isotopic evidence for monochlorobenzene and benzene degradation under anaerobic conditions in contaminated sediments. WATER RESEARCH 2021; 207:117809. [PMID: 34741903 DOI: 10.1016/j.watres.2021.117809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 08/10/2021] [Accepted: 10/22/2021] [Indexed: 06/13/2023]
Abstract
Industrial chemicals are frequently detected in sediments due to a legacy of chemical spills. Globally, site remedies for groundwater and sediment decontamination include natural attenuation by in situ abiotic and biotic processes. Compound-specific isotope analysis (CSIA) is a diagnostic tool to identify, quantify, and characterize degradation processes in situ, and in some cases can differentiate between abiotic degradation and biodegradation. This study reports high-resolution carbon, chlorine, and hydrogen stable isotope profiles for monochlorobenzene (MCB), and carbon and hydrogen stable isotope profiles for benzene, coupled with measurements of pore water concentrations in contaminated sediments. Multi-element isotopic analysis of δ13C and δ37Cl for MCB were used to generate dual-isotope plots, which for 2 locations at the study site resulted in ΛC/Cl(130) values of 1.42 ± 0.19 and ΛC/Cl(131) values of 1.70 ± 0.15, consistent with theoretical calculations for carbon-chlorine bond cleavage (ΛT = 1.80 ± 0.31) via microbial reductive dechlorination. For benzene, significant δ2H (122‰) and δ13C (6‰) depletion trends, followed by enrichment trends in δ13C (1.6‰) in the upper part of the sediment, were observed at the same location, indicating not only production of benzene due to biodegradation of MCB, but subsequent biotransformation of benzene itself to nontoxic end-products. Degradation rate constants calculated independently using chlorine isotopic data and carbon isotopic data, respectively, agreed within uncertainty thus providing multiple lines of evidence for in situ contaminant degradation via reductive dechlorination and providing the foundation for a novel approach to determine site-specific in situ rate estimates essential for the prediction of remediation outcomes and timelines.
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Affiliation(s)
- Tetyana Gilevska
- Department of Earth Sciences, University of Toronto, Toronto, ON M5S 3B1, Canada; CNRS/EOST, ITES UMR 7063, Earth and Environment Institute of Strasbourg (ITES), University of Strasbourg, Strasbourg, 67084, France
| | - Ann Sullivan Ojeda
- Department of Earth Sciences, University of Toronto, Toronto, ON M5S 3B1, Canada; Department of Geosciences, Auburn University, Auburn, AL 36849, United States
| | - Steffen Kümmel
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research, UFZ, Leipzig, 04318, Germany
| | - Matthias Gehre
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research, UFZ, Leipzig, 04318, Germany
| | - Edward Seger
- The Chemours Company, Wilmington, DE 19810, United States
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9
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Ojeda AS, Zheng J, Phillips E, Sherwood Lollar B. Implications of regression bias for multi-element isotope analysis for environmental remediation. Talanta 2021; 226:122113. [PMID: 33676669 DOI: 10.1016/j.talanta.2021.122113] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 01/07/2021] [Accepted: 01/09/2021] [Indexed: 11/24/2022]
Abstract
Measuring changes in the stable isotope ratios of multiple elements (e.g. Δδ13C, Δδ37Cl, and Δδ2H) during the (bio)transformation of environmental contaminants has provided new insights into reaction mechanisms and tools to optimize remediation efforts. Dual-isotope analysis, wherein changes in one isotopic system are plotted against another (to derive an interpretational parameter expressed as Λ), is a key tool in multi-element isotopic assessment. To date, most dual-isotope analyses use ordinary linear regression (OLR) for the calculation, which can be subject to regression attenuation and thus an inherent artifact that depresses slope values, expressed as Λ. Here, a series of Monte Carlo simulations were constructed to represent common data conditions and variations within dual-isotope data to test the degree of bias when deriving Λ using OLR compared to an alternative regression technique, the York method. The degree of bias was quantified compared to the modeled or "true" Λ value. For all simulations, the York method provided the least bias in slope estimates (<1%) over all data conditions tested. In contrast, OLR produced unbiased estimates only under a limited set of conditions, which was validated through a mathematical model proof. Both the mathematical model and simulations show that bias of at least 5% in OLR occurs when the extent of enrichment in the x-variable (XM) is equal to or less than ≈15 times the 1σ precision in the isotope measurement (σX), for both Cl/C and C/H plots. The results give practitioners tools to evaluate whether bias is present in data and to estimate the extent to which this negatively impacts the interpretations and predictions of remediation potential for new and previously published datasets. This study demonstrates that integration of such robust statistical tools is essential for dual-isotope interpretations widely used in contaminant hydrogeology but relevant to other disciplines including environmental chemistry and ecology.
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Affiliation(s)
| | - Jingyi Zheng
- Auburn University, Department of Mathematics and Statistics, Auburn, AL, 36849, USA
| | - Elizabeth Phillips
- University of Toronto, Department of Earth Sciences, Toronto, ON, M5S 3B1, Canada
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10
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Gafni A, Gelman F, Ronen Z, Bernstein A. Variable carbon and chlorine isotope fractionation in TCE co-metabolic oxidation. CHEMOSPHERE 2020; 242:125130. [PMID: 31669996 DOI: 10.1016/j.chemosphere.2019.125130] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 10/12/2019] [Accepted: 10/14/2019] [Indexed: 06/10/2023]
Abstract
Identifying co-metabolic TCE oxidation in polluted groundwater is challenging due to lack of indicative by-products. This challenge may theoretically be resolved if the oxidation process can be characterized by a distinct dual isotope enrichment. In this work, we aimed to explore the carbon and chlorine isotope effects associated with TCE oxidation by a variety of oxygenases. These included pure strains and enrichment cultures of methane, toluene and ammonia oxidizers, as well as experiments with crude extracts. Isotope effects determined for TCE oxidation by toluene and ammonia oxidizers were mostly in line with expected values for epoxidation mechanism (ϵ13C -11.0 ± 0.7 to -24.8 ± 0.2‰ and ϵ37Cl +0.9 ± 0.5 to +1.0 ± 0.4‰), whereas, the methanotrophs resulted in distinctively different isotope effects (ϵ13C -2.4 ± 0.4 to -3.4 ± 0.8‰ and ϵ37Cl -1.8 ± 0.2 to -2.9 ± 0.9‰). It is suggested that in TCE oxidation by methanotrophs, substrate binding rather than bond cleavage is rate limiting, leading to this unexpected isotope effect. On the environmental level, our results imply that the oxidative process can be differentiated if catalyzed by toluene and ammonia oxidizers or by methanotrophs. Additionally, the oxidative process can be distinguished from the reductive one. However, using dual isotope analysis in the field may result in an under-estimation of the overall co-metabolic process if methanotrophs are to be excluded due to low isotope effects.
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Affiliation(s)
- Almog Gafni
- Zuckerberg Institute for Water Research, Department of Environmental Hydrology and Microbiology, Ben-Gurion University of the Negev, Sede Boqer Campus, 8499000, Israel
| | - Faina Gelman
- Geological Survey of Israel, 32 Yesha'ayahu Leibowitz St, Jerusalem, 9692100, Israel
| | - Zeev Ronen
- Zuckerberg Institute for Water Research, Department of Environmental Hydrology and Microbiology, Ben-Gurion University of the Negev, Sede Boqer Campus, 8499000, Israel
| | - Anat Bernstein
- Zuckerberg Institute for Water Research, Department of Environmental Hydrology and Microbiology, Ben-Gurion University of the Negev, Sede Boqer Campus, 8499000, Israel.
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11
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Knossow N, Siebner H, Bernstein A. Isotope Fractionation (δ 13C, δ 15N) in the Microbial Degradation of Bromoxynil by Aerobic and Anaerobic Soil Enrichment Cultures. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:1546-1554. [PMID: 31986047 DOI: 10.1021/acs.jafc.9b07653] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Bromoxynil is an increasingly applied nitrile herbicide. Under aerobic conditions, hydration, nitrilation, or hydroxylation of the nitrile group commonly occurs, whereas under anaerobic conditions reductive dehalogenation is common. This work studied the isotope effects associated with these processes by soil cultures. The aerobic soil enrichment culture presented a significant increase in Stenotrophomonas, Pseudomonas, Chryseobacterium, Achromobacter, Azospirillum, and Arcticibacter, and degradation products indicated that nitrile hydratase was the dominant degradation route. The anaerobic culture was dominated by Proteobacteria and Firmicutes phyla with a significant increase in Dethiosulfatibacter, and degradation products indicated reductive debromination as a major degradation route. Distinct dual-isotope trends (δ13C, δ15N) were determined for the two routes: a strong inverse nitrogen isotope effect (εN = 10.56 ± 0.36‰) and an insignificant carbon isotope effect (εC = 0.37 ± 0.36‰) for the aerobic process versus a negligible effect for both elements in the anaerobic process. These trends differ from formerly reported trends for the photodegradation of bromoxynil and enable one to distinguish between the processes in the field.
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Affiliation(s)
- Nadav Knossow
- Zuckerberg Institute for Water Research, Department of Environmental Hydrology and Microbiology , Ben-Gurion University of the Negev , Sede Boqer Campus , Sede Boqer 8499000 , Israel
| | - Hagar Siebner
- Zuckerberg Institute for Water Research, Department of Environmental Hydrology and Microbiology , Ben-Gurion University of the Negev , Sede Boqer Campus , Sede Boqer 8499000 , Israel
| | - Anat Bernstein
- Zuckerberg Institute for Water Research, Department of Environmental Hydrology and Microbiology , Ben-Gurion University of the Negev , Sede Boqer Campus , Sede Boqer 8499000 , Israel
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12
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Büsing J, Buchner D, Behrens S, Haderlein SB. Deciphering the Variability of Stable Isotope (C, Cl) Fractionation of Tetrachloroethene Biotransformation by Desulfitobacterium strains Carrying Different Reductive Dehalogenases Enzymes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:1593-1602. [PMID: 31880148 DOI: 10.1021/acs.est.9b05606] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Kinetic isotope effects have been used successfully to prove and characterize organic contaminant transformation on various scales including field and laboratory studies. For tetrachloroethene (PCE) biotransformation, however, causes for the substantial variability of reported isotope enrichment factors (ε) are still not deciphered (εC = -0.4 to -19.0‰). Factors such as different reaction mechanisms and masking of isotope fractionation by either limited intracellular mass transfer or rate-limitations within the enzymatic multistep reaction are under discussion. This study evaluated the contribution of these factors to the magnitude of carbon and chlorine isotope fractionation of Desulfitobacterium strains harboring three different PCE-transforming enzymes (PCE-RdhA). Despite variable single element isotope fractionation (εC = -5.0 to -19.7‰; εCl = -1.9 to -6.3‰), similar slopes of dual element isotope plots (ΛC/Cl values of 2.4 ± 0.1 to 3.6 ± 0.1) suggest a common reaction mechanism for different PCE-RdhAs. Cell envelope properties of the Desulfitobacterium strains allowed to exclude masking effects due to PCE mass transfer limitation. Our results thus revealed that different rate-limiting steps (e.g., substrate channel diffusion) in the enzymatic multistep reactions of individual PCE-RdhAs rather than different reaction mechanisms determine the extent of PCE isotope fractionation in the Desulfitobacterium genus.
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Affiliation(s)
- Johannes Büsing
- Center for Applied Geoscience , University of Tübingen , 72074 Tübingen , Germany
| | - Daniel Buchner
- Center for Applied Geoscience , University of Tübingen , 72074 Tübingen , Germany
| | - Sebastian Behrens
- Department of Civil, Environmental, and Geo-Engineering , University of Minnesota , Minneapolis , Minnesota 55455 , United States
| | - Stefan B Haderlein
- Center for Applied Geoscience , University of Tübingen , 72074 Tübingen , Germany
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13
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Chen S, Zhang K, Jha RK, Ma L. Impact of atrazine concentration on bioavailability and apparent isotope fractionation in Gram-negative Rhizobium sp. CX-Z. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 257:113614. [PMID: 31761577 DOI: 10.1016/j.envpol.2019.113614] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 11/10/2019] [Accepted: 11/10/2019] [Indexed: 06/10/2023]
Abstract
Compound-specific stable isotope analysis of micropollutants has become an established method for the qualitative and quantitative assessment of biodegradation in the field. However, many of environmental factors may have an influence on the observed isotope fractionation. Herein, we investigate the impact of substrate concentration on the observed enrichment factor derived from Rayleigh plot of batch laboratory experiments conducted to measure the atrazine carbon isotope fractionation of Rhizobium sp. CX-Z subjected to the different initial concentration level of atrazine. The Rayleigh plot (changes in bulk concentration vs. isotopic composition) derived from batch experiments shown divergence from the linear relation towards the end of degradation, confirming bioavailability of atrazine changed along with the decay of substrate concentration, consequently, influenced the isotope fractionation and lowered the observed enrichment factor. When microbial degradation is coupled to a mass transfer step limiting the bioavailability of substrate, the observed enrichment factor displays a dependence on initial atrazine concentration. Observed enrichment factors (ε) (absolute value) derived from the low concentration (i.e. 9.5 μM) are below 3.5‰ to the value of -5.4‰ determined at high bioavailability (membrane-free cells). The observed enrichment factor depended significantly on the atrazine concentration, indicating the concentration level and the bioavailability of a substrate in realistic environments should be considered during the assessment of microbial degradation or in situ bioremediation based on compound-specific stable isotope analysis (CSIA) method.
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Affiliation(s)
- Songsong Chen
- State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Kai Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092, China
| | - Rohit Kumar Jha
- State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092, China
| | - Limin Ma
- State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
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14
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Liu Y, Wu L, Kohli P, Kumar R, Stryhanyuk H, Nijenhuis I, Lal R, Richnow HH. Enantiomer and Carbon Isotope Fractionation of α-Hexachlorocyclohexane by Sphingobium indicum Strain B90A and the Corresponding Enzymes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:8715-8724. [PMID: 31266304 DOI: 10.1021/acs.est.9b01233] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Chiral organic contaminants, like α-hexachlorocyclohexane (α-HCH), showed isotope fractionation and enantiomer fractionation during biodegradation. This study aims to understand the correlation between these two processes. Initial tests of α-HCH degradation by six Sphingobium strains (with different LinA variants) were conducted. Results showed variable enantiomer selectivity over the time course. In contrast, constant enantiomer selectivity was observed in experiments employing (i) cell suspensions, (ii) crude extracts, or (iii) LinA1 and LinA2 enzymes of strain B90A for α-HCH degradation in enzyme activity assay buffer. The average value of enantioselectivity (ES) were -0.45 ± 0.03 (cell suspensions), -0.60 ± 0.05 (crude extracts), and 1 (LinA1) or -1 (LinA2). The average carbon isotope enrichment factors (εc) of (+)α- and (-)α-HCH were increased from cells suspensions (-6.3 ± 0.1‰ and -2.3 ± 0.03‰) over crude extracts (-7.7 ± 0.4‰ and -3.4 ± 0.02‰) to purified enzymes (-11.1 ± 0.3‰ and -3.8 ± 0.2‰). The variability of ES and the εc were discussed based on the effect of mass transport and degradation rates. Our study demonstrates that enantiomer and isotope fractionation of α-HCH are two independent processes and both are affected by underlying reactions of individual enzymes and mass transport to a different extent.
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Affiliation(s)
- Yaqing Liu
- Department of Isotope Biogeochemistry , Helmholtz Centre for Environmental Research-UFZ , Permoserstraße 15 , 04318 Leipzig , Germany
| | - Langping Wu
- Department of Isotope Biogeochemistry , Helmholtz Centre for Environmental Research-UFZ , Permoserstraße 15 , 04318 Leipzig , Germany
| | - Puneet Kohli
- Molecular Biology Laboratory, Department of Zoology , University of Delhi , Delhi - 110007 , India
| | - Roshan Kumar
- Molecular Biology Laboratory, Department of Zoology , University of Delhi , Delhi - 110007 , India
| | - Hryhoriy Stryhanyuk
- Department of Isotope Biogeochemistry , Helmholtz Centre for Environmental Research-UFZ , Permoserstraße 15 , 04318 Leipzig , Germany
| | - Ivonne Nijenhuis
- Department of Isotope Biogeochemistry , Helmholtz Centre for Environmental Research-UFZ , Permoserstraße 15 , 04318 Leipzig , Germany
| | - Rup Lal
- Molecular Biology Laboratory, Department of Zoology , University of Delhi , Delhi - 110007 , India
| | - Hans-Hermann Richnow
- Department of Isotope Biogeochemistry , Helmholtz Centre for Environmental Research-UFZ , Permoserstraße 15 , 04318 Leipzig , Germany
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15
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Liu J, Lin H, Dong Y, Li B. Elucidating the biodegradation mechanism of tributyl phosphate (TBP) by Sphingomonas sp. isolated from TBP-contaminated mine tailings. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 250:284-291. [PMID: 30999205 DOI: 10.1016/j.envpol.2019.03.127] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 03/29/2019] [Accepted: 03/30/2019] [Indexed: 05/22/2023]
Abstract
Tributyl phosphate (TBP) is recognised as a global environmental contaminant because of its wide use in floatation reagents, nuclear fuel reprocessing and plasticisers. This contaminant is hardly degraded by hydrolysis in the environment due to its special physicochemical properties. In this study, one TBP-degrading strain was isolated from TBP-contaminated abandoned mine tailings, and 16S rRNA identification revealed that the strain belonged to the genus Sphingomonas. Results validated that the strain could utilise TBP as the sole carbon source, and vitamin was not the essential factor for its growth. Liquid chromatography time-of-flight mass spectrometry analysis identified di-n-butyl phosphate (DnBP) and mono-n-butyl phosphate (MnBP) as the intermediate metabolites for TBP biodegradation. No obvious change in carbon and hydrogen isotope composition was observed in biodegradation processes (cell suspension and crude extract degradation), which indicated that the first irreversible bond cleavage did not involve carbon or hydrogen. Hence, the TBP degradation scheme by Sphingomonas sp. proposed that the first irreversible step of TBP transferred to DnBP would lead to PO bond cleavage. This study combined the identification of products and isotope fractionation in substrates to investigate the transformation mechanism, thereby providing an eco-friendly and cost-effective way for the in situ bioremediation of TBP-contaminated sites by the isolated TBP degradation strain.
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Affiliation(s)
- Jia Liu
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, PR China; Beijing Key Laboratory on Resource-oriented Treatment of Industrial Pollutants, Beijing, 100083, China
| | - Hai Lin
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, PR China; Beijing Key Laboratory on Resource-oriented Treatment of Industrial Pollutants, Beijing, 100083, China.
| | - Yingbo Dong
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, PR China; Beijing Key Laboratory on Resource-oriented Treatment of Industrial Pollutants, Beijing, 100083, China
| | - Bing Li
- School of Energy and Environmental Engineering, University of Science and Technology Beijing, Beijing, 100083, PR China; Beijing Key Laboratory on Resource-oriented Treatment of Industrial Pollutants, Beijing, 100083, China
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16
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Chen S, Zhang K, Jha RK, Chen C, Yu H, Liu Y, Ma L. Isotope fractionation in atrazine degradation reveals rate-limiting, energy-dependent transport across the cell membrane of gram-negative rhizobium sp. CX-Z. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 248:857-864. [PMID: 30856501 DOI: 10.1016/j.envpol.2019.02.078] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 02/12/2019] [Accepted: 02/22/2019] [Indexed: 05/22/2023]
Abstract
In the biological mass transfer of organic contaminants like atrazine, the cellular membrane limits bioavailability of pesticides. We aimed to illustrate the roles of cellular membrane physiology and substrate uptake (e.g., passive diffusion and energy-dependent transport) on the limitations of bioavailability in atrazine biodegradation by Gram-negative strain Rhizobium sp. CX-Z. Compound-specific stable isotope analysis revealed energy-dependent transport across cellular membrane led to bioavailability limitations in atrazine biotransformation. Carbon isotope fractionation (ε(C) = -1.8 ± 0.3‰) was observed and significantly smaller in atrazine biodegradation by Rhizobium sp. CX-Z than that expected in acid hydrolysis (ε(C) = -4.8 ± 0.4‰) and hydrolysis by the pure enzyme TrzN (ε(C) = -5.0 ± 0.2‰). However, isotope fractionation was restored in membrane-free cells of Rhizobium sp. CX-Z (ε(C) = -5.4 ± 0.2‰) where no cellular membrane limits substrate uptake. When respiratory chain was inhibited by rotenone, the pseudo-first order kinetic rate constants (0.08 ± 0.03 h-1, 0.09 ± 0.03 h-1) was observed to be statistically less than in the control group (0.23 ± 0.02 h-1, 0.33 ± 0.02 h-1), demonstrating that energy-dependent transport dominated atrazine transfer across the cellular membrane. Therefore, our results revealed energy-dependent transport across cellular membrane existing in Gram-negative strain Rhizobium sp. CX-Z determines bioavailability of atrazine in biotransformation process even at high concentration.
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Affiliation(s)
- Songsong Chen
- State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China
| | - Kai Zhang
- State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai, 200092, China
| | - Rohit Kumar Jha
- State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai, 200092, China
| | - Chong Chen
- State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai, 200092, China
| | - Haiyan Yu
- State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai, 200092, China
| | - Ying Liu
- State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai, 200092, China
| | - Limin Ma
- State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, PR China.
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17
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Schilling IE, Hess R, Bolotin J, Lal R, Hofstetter TB, Kohler HPE. Kinetic Isotope Effects of the Enzymatic Transformation of γ-Hexachlorocyclohexane by the Lindane Dehydrochlorinase Variants LinA1 and LinA2. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:2353-2363. [PMID: 30674184 DOI: 10.1021/acs.est.8b04234] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Compound-specific isotope analysis (CSIA) can provide insights into the natural attenuation processes of hexachlorocyclohexanes (HCHs), an important class of persistent organic pollutants. However, the interpretation of HCH stable isotope fractionation is conceptually challenging. HCHs exist as different conformers that can be converted into each other, and the enzymes responsible for their transformation discriminate among those HCH conformers. Here, we investigated the enzyme specificity of apparent 13C- and 2H-kinetic isotope effects (AKIEs) associated with the dehydrochlorination of γ-HCH (lindane) by two variants of the lindane dehydrochlorinases LinA1 and LinA2. While LinA1 and LinA2 attack γ-HCH at different trans-1,2-diaxial H-C-C-Cl moieties, the observed C and H isotope fractionation was large, typical for bimolecular eliminations, and was not affected by conformational mobility. 13C-AKIEs for transformation by LinA1 and LinA2 were the same (1.024 ± 0.001 and 1.025 ± 0.001, respectively), whereas 2H-AKIEs showed minor differences (2.4 ± 0.1 and 2.6 ± 0.1). Variations of isotope effects between LinA1 and LinA2 are small and in the range reported for different degrees of C-H bond cleavage in transition states of dehydrochlorination reactions. The large C and H isotope fractionation reported here for experiments with pure enzymes contrasts with previous observations from whole cell experiments and suggests that specific uptake processes by HCH-degrading microorganisms might modulate the observable HCH isotope fractionation at contaminated sites.
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Affiliation(s)
- Iris E Schilling
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf , Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics , ETH Zürich , CH-8092 Zürich , Switzerland
| | - Ramon Hess
- Institute of Biogeochemistry and Pollutant Dynamics , ETH Zürich , CH-8092 Zürich , Switzerland
| | - Jakov Bolotin
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf , Switzerland
| | - Rup Lal
- Department of Zoology , University of Delhi , Delhi 110007 , India
| | - Thomas B Hofstetter
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf , Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics , ETH Zürich , CH-8092 Zürich , Switzerland
| | - Hans-Peter E Kohler
- Eawag, Swiss Federal Institute of Aquatic Science and Technology , CH-8600 Dübendorf , Switzerland
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18
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Ehrl B, Kundu K, Gharasoo M, Marozava S, Elsner M. Rate-Limiting Mass Transfer in Micropollutant Degradation Revealed by Isotope Fractionation in Chemostat. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:1197-1205. [PMID: 30514083 PMCID: PMC6365907 DOI: 10.1021/acs.est.8b05175] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 12/03/2018] [Accepted: 12/05/2018] [Indexed: 05/05/2023]
Abstract
Biodegradation of persistent micropollutants like pesticides often slows down at low concentrations (μg/L) in the environment. Mass transfer limitations or physiological adaptation are debated to be responsible. Although promising, evidence from compound-specific isotope fractionation analysis (CSIA) remains unexplored for bacteria adapted to this low concentration regime. We accomplished CSIA for degradation of a persistent pesticide, atrazine, during cultivation of Arthrobacter aurescens TC1 in chemostat under four different dilution rates leading to 82, 62, 45, and 32 μg/L residual atrazine concentrations. Isotope analysis of atrazine in chemostat experiments with whole cells revealed a drastic decrease in isotope fractionation with declining residual substrate concentration from ε(C) = -5.36 ± 0.20‰ at 82 μg/L to ε(C) = -2.32 ± 0.28‰ at 32 μg/L. At 82 μg/L ε(C) represented the full isotope effect of the enzyme reaction. At lower residual concentrations smaller ε(C) indicated that this isotope effect was masked indicating that mass transfer across the cell membrane became rate-limiting. This onset of mass transfer limitation appeared in a narrow concentration range corresponding to about 0.7 μM assimilable carbon. Concomitant changes in cell morphology highlight the opportunity to study the role of this onset of mass transfer limitation on the physiological level in cells adapted to low concentrations.
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Affiliation(s)
- Benno
N. Ehrl
- Institute
of Groundwater Ecology, Helmholtz Zentrum
München, Ingolstädter
Landstrasse 1, 85764 Neuherberg, Germany
| | - Kankana Kundu
- Institute
of Groundwater Ecology, Helmholtz Zentrum
München, Ingolstädter
Landstrasse 1, 85764 Neuherberg, Germany
| | - Mehdi Gharasoo
- Institute
of Groundwater Ecology, Helmholtz Zentrum
München, Ingolstädter
Landstrasse 1, 85764 Neuherberg, Germany
| | - Sviatlana Marozava
- Institute
of Groundwater Ecology, Helmholtz Zentrum
München, Ingolstädter
Landstrasse 1, 85764 Neuherberg, Germany
| | - Martin Elsner
- Institute
of Groundwater Ecology, Helmholtz Zentrum
München, Ingolstädter
Landstrasse 1, 85764 Neuherberg, Germany
- Chair
of Analytical Chemistry and Water Chemistry, Technical University of Munich, Marchioninistrasse 17, 81377 Munich, Germany
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19
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Chen G, Han J, Mu Y, Yu H, Qin L. Two-stage chromium isotope fractionation during microbial Cr(VI) reduction. WATER RESEARCH 2019; 148:10-18. [PMID: 30343194 DOI: 10.1016/j.watres.2018.09.034] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 09/17/2018] [Accepted: 09/18/2018] [Indexed: 06/08/2023]
Abstract
Chromium isotope fractionation analysis is a promising approach for the assessment of microbial Cr(VI) reduction in groundwater. Understanding the mechanisms and other parameters that control Cr isotope fractionation factors (between the product Cr(III) and reactant Cr (VI)) in microbial Cr(VI) reduction is critical to this application. To date, such studies are very limited. Here, the influence of critical factors on observed Cr isotope fractionation during Cr(VI) reduction by Shewanella oneidensis MR-1 under various conditions was investigated. The Cr(VI) concentration and Cr isotope ratio measurements were conducted on unreacted Cr(VI) remaining in solution to determine Cr isotope fractionation factors. The changes in ambient environmental conditions (e.g., pH, temperature) have limited influence on Cr isotope fractionation factors. However, as a result of Cr(VI) consumption as the experiments proceed, the change in bioavailability of Cr(VI) has a significant impact on Cr isotope fractionation factors. For example, in temperature-controlled experiments, Cr isotope fractionation showed two-stage behavior: during Stage I, the values of ε were -2.81 ± 0.19‰ and -2.60 ± 0.14‰ at 18 °C and 34 °C, respectively; during Stage II, as Cr(VI) reduction progressed, Cr isotope fractionation was significantly masked, and the ε values decreased to -0.98 ± 0.49‰ and -1.01 ± 0.11‰ at 18 °C and 34 °C, respectively. Similar two-stage isotope fractionation behaviors were observed in pH-controlled experiments (pH = 6.0 and 7.2) and in experiments with and without the addition of a competing electron acceptor (nitrate). Masking of isotope fractionation in Stage II indicated restrictions on the bioavailability of Cr(VI) and mass-transfer limitations. This study provides an explanation for the variation in Cr isotope fractionation factors during microbial Cr(VI) reduction in the environment, furthering the viability of Cr isotope ratio analysis as an approach in understanding Cr biogeochemical cycling.
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Affiliation(s)
- Guojun Chen
- CAS Key Laboratory of Crust-Mantle Materials and Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, China
| | - Juncheng Han
- CAS Key Laboratory for Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei, 230026, China
| | - Yang Mu
- CAS Key Laboratory for Urban Pollutant Conversion, Department of Chemistry, University of Science & Technology of China, Hefei, 230026, China
| | - Huimin Yu
- CAS Key Laboratory of Crust-Mantle Materials and Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, China
| | - Liping Qin
- CAS Key Laboratory of Crust-Mantle Materials and Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, China; State Key Laboratory of Geological Processes and Mineral Resources, University of Geosciences, Beijing, China.
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20
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Hermon L, Denonfoux J, Hellal J, Joulian C, Ferreira S, Vuilleumier S, Imfeld G. Dichloromethane biodegradation in multi-contaminated groundwater: Insights from biomolecular and compound-specific isotope analyses. WATER RESEARCH 2018; 142:217-226. [PMID: 29885622 DOI: 10.1016/j.watres.2018.05.057] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 05/25/2018] [Accepted: 05/30/2018] [Indexed: 06/08/2023]
Abstract
Dichloromethane (DCM) is a widespread and toxic industrial solvent which often co-occurs with chlorinated ethenes at polluted sites. Biodegradation of DCM occurs under both oxic and anoxic conditions in soils and aquifers. Here we investigated in situ and ex situ biodegradation of DCM in groundwater sampled from the industrial site of Themeroil (France), where DCM occurs as a major co-contaminant of chloroethenes. Carbon isotopic fractionation (εC) for DCM ranging from -46 to -22‰ were obtained under oxic or denitrifying conditions, in mineral medium or contaminated groundwater, and for laboratory cultures of Hyphomicrobium sp. strain GJ21 and two new DCM-degrading strains isolated from the contaminated groundwater. The extent of DCM biodegradation (B%) in the aquifer, as evaluated by compound-specific isotope analysis (δ13C), ranged from 1% to 85% applying DCM-specific εC derived from reference strains and those determined in this study. Laboratory groundwater microcosms under oxic conditions showed DCM biodegradation rates of up to 0.1 mM·day-1, with concomitant chloride release. Dehalogenase genes dcmA and dhlA involved in DCM biodegradation ranged from below 4 × 102 (boundary) to 1 × 107 (source zone) copies L-1 across the contamination plume. High-throughput sequencing on the 16S rrnA gene in groundwater samples showed that both contaminant level and terminal electron acceptor processes (TEAPs) influenced the distribution of genus-level taxa associated with DCM biodegradation. Taken together, our results demonstrate the potential of DCM biodegradation in multi-contaminated groundwater. This integrative approach may be applied to contaminated aquifers in the future, in order to identify microbial taxa and pathways associated with DCM biodegradation in relation to redox conditions and co-contamination levels.
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Affiliation(s)
- L Hermon
- Université de Strasbourg, CNRS, GMGM UMR 7156, Department of Microbiology, Genomics and the Environment, Strasbourg, France; BRGM, Geomicrobiology and Environmental Monitoring Unit, Orléans, France
| | - J Denonfoux
- Service Recherche, Développement et Innovation-Communautés Microbiennes, GenoScreen Lille, France
| | - J Hellal
- BRGM, Geomicrobiology and Environmental Monitoring Unit, Orléans, France
| | - C Joulian
- BRGM, Geomicrobiology and Environmental Monitoring Unit, Orléans, France
| | - S Ferreira
- Service Recherche, Développement et Innovation-Communautés Microbiennes, GenoScreen Lille, France
| | - S Vuilleumier
- Université de Strasbourg, CNRS, GMGM UMR 7156, Department of Microbiology, Genomics and the Environment, Strasbourg, France
| | - G Imfeld
- Université de Strasbourg, CNRS/EOST, LHyGeS UMR 7517, Laboratory of Hydrology and Geochemistry of Strasbourg, Strasbourg, France.
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21
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Chen G, Shouakar-Stash O, Phillips E, Justicia-Leon SD, Gilevska T, Sherwood Lollar B, Mack EE, Seger ES, Löffler FE. Dual Carbon-Chlorine Isotope Analysis Indicates Distinct Anaerobic Dichloromethane Degradation Pathways in Two Members of Peptococcaceae. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:8607-8616. [PMID: 29975517 DOI: 10.1021/acs.est.8b01583] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Dichloromethane (DCM) is a probable human carcinogen and frequent groundwater contaminant and contributes to stratospheric ozone layer depletion. DCM is degraded by aerobes harboring glutathione-dependent DCM dehalogenases; however, DCM contamination occurs in oxygen-deprived environments, and much less is known about anaerobic DCM metabolism. Some members of the Peptococcaceae family convert DCM to environmentally benign products including acetate, formate, hydrogen (H2), and inorganic chloride under strictly anoxic conditions. The current study applied stable carbon and chlorine isotope fractionation measurements to the axenic culture Dehalobacterium formicoaceticum and to the consortium RM comprising DCM degrader Candidatus Dichloromethanomonas elyunquensis. Degradation-associated carbon and chlorine isotope enrichment factors (εC and εCl) of -42.4 ± 0.7‰ and -5.3 ± 0.1‰, respectively, were measured in D. formicoaceticum cultures. A similar εCl of -5.2 ± 0.1‰, but a substantially lower εC of -18.3 ± 0.2‰, were determined for Ca. Dichloromethanomonas elyunquensis. The εC and εCl values resulted in distinctly different dual element C-Cl isotope correlations (ΛC/Cl = Δδ13C/Δδ37Cl) of 7.89 ± 0.12 and 3.40 ± 0.03 for D. formicoaceticum and Ca. Dichloromethanomonas elyunquensis, respectively. The distinct ΛC/Cl values obtained for the two cultures imply mechanistically distinct C-Cl bond cleavage reactions, suggesting that members of Peptococcaceae employ different pathways to metabolize DCM. These findings emphasize the utility of dual carbon-chlorine isotope analysis to pinpoint DCM degradation mechanisms and to provide an additional line of evidence that detoxification is occurring at DCM-contaminated sites.
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Affiliation(s)
- Gao Chen
- Center for Environmental Biotechnology, Department of Civil and Environmental Engineering, and Department of Microbiology , University of Tennessee , Knoxville , Tennessee 37996 , United States
| | - Orfan Shouakar-Stash
- Isotope Tracer Technologies Inc. (IT2) , Waterloo , Ontario N2 V 1Z5 , Canada
- Department of Earth and Environmental Sciences , University of Waterloo , Waterloo , Ontario N2L 3G1 , Canada
- School of Engineering , University of Guelph , Guelph , Ontario N1G 2W1 , Canada
| | - Elizabeth Phillips
- Department of Earth Sciences , University of Toronto , Toronto , Ontario M5S 3B1 , Canada
| | - Shandra D Justicia-Leon
- School of Biology , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Tetyana Gilevska
- Department of Earth Sciences , University of Toronto , Toronto , Ontario M5S 3B1 , Canada
| | | | - E Erin Mack
- DuPont Corporate Remediation Group , E. I. DuPont de Nemours and Company , Wilmington , Delaware 19805 , United States
| | - Edward S Seger
- The Chemours Company , Wilmington , Delaware 19899 , United States
| | - Frank E Löffler
- Center for Environmental Biotechnology, Department of Civil and Environmental Engineering, and Department of Microbiology , University of Tennessee , Knoxville , Tennessee 37996 , United States
- Oak Ridge National Laboratory (UT-ORNL) Joint Institute for Biological Sciences (JIBS) and Biosciences Division , University of Tennessee and Oak Ridge National Laboratory , Oak Ridge , Tennessee 37831 , United States
- Department of Biosystems Engineering and Soil Science , University of Tennessee , Knoxville , Tennessee 37996 , United States
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22
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Liu N, Ding L, Li H, Zhang P, Zheng J, Weng CH. Stable carbon isotope fractionation of chlorinated ethenes by a microbial consortium containing multiple dechlorinating genes. BIORESOURCE TECHNOLOGY 2018; 261:133-141. [PMID: 29656226 DOI: 10.1016/j.biortech.2018.04.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 04/02/2018] [Accepted: 04/04/2018] [Indexed: 06/08/2023]
Abstract
The study aimed to determine the possible contribution of specific growth conditions and community structures to variable carbon enrichment factors (Ɛ-carbon) values for the degradation of chlorinated ethenes (CEs) by a bacterial consortium with multiple dechlorinating genes. Ɛ-carbon values for trichloroethylene, cis-1,2-dichloroethylene, and vinyl chloride were -7.24% ± 0.59%, -14.6% ± 1.71%, and -21.1% ± 1.14%, respectively, during their degradation by a microbial consortium containing multiple dechlorinating genes including tceA and vcrA. The Ɛ-carbon values of all CEs were not greatly affected by changes in growth conditions and community structures, which directly or indirectly affected reductive dechlorination of CEs by this consortium. Stability analysis provided evidence that the presence of multiple dechlorinating genes within a microbial consortium had little effect on carbon isotope fractionation, as long as the genes have definite, non-overlapping functions.
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Affiliation(s)
- Na Liu
- College of Environment and Resources, Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China
| | - Longzhen Ding
- College of Environment and Resources, Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China
| | - Haijun Li
- Sichuan University of Science & Engineering, Sichuan, China
| | - Pengpeng Zhang
- College of Environment and Resources, Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China
| | - Jixing Zheng
- College of Environment and Resources, Key Laboratory of Groundwater Resources and Environment, Ministry of Education, Jilin University, Changchun 130021, China
| | - Chih-Huang Weng
- Department of Civil and Ecological Engineering, I-Shou University, Kaohsiung City 84008, Taiwan.
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23
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Ehrl B, Gharasoo M, Elsner M. Isotope Fractionation Pinpoints Membrane Permeability as a Barrier to Atrazine Biodegradation in Gram-negative Polaromonas sp. Nea-C. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:4137-4144. [PMID: 29495658 PMCID: PMC6331012 DOI: 10.1021/acs.est.7b06599] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Biodegradation of persistent pesticides like atrazine often stalls at low concentrations in the environment. While mass transfer does not limit atrazine degradation by the Gram-positive Arthrobacter aurescens TC1 at high concentrations (>1 mg/L), evidence of bioavailability limitations is emerging at trace concentrations (<0.1 mg/L). To assess the bioavailability constraints on biodegradation, the roles of cell wall physiology and transporters remain imperfectly understood. Here, compound-specific isotope analysis (CSIA) demonstrates that cell wall physiology (i.e., the difference between Gram-negative and Gram-positive bacteria) imposes mass transfer limitations in atrazine biodegradation even at high concentrations. Atrazine biodegradation by Gram-negative Polaromonas sp. Nea-C caused significantly less isotope fractionation (ε(C) = -3.5 ‰) than expected for hydrolysis by the enzyme TrzN (ε(C) = -5.0 ‰) and observed in Gram-positive Arthrobacter aurescens TC1 (ε(C) = -5.4 ‰). Isotope fractionation was recovered in cell-free extracts (ε(C) = -5.3 ‰) where no cell envelope restricted pollutant uptake. When active transport was inhibited with cyanide, atrazine degradation rates remained constant demonstrating that atrazine mass transfer across the cell envelope does not depend on active transport but is a consequence of passive cell wall permeation. Taken together, our results identify the cell envelope of the Gram-negative bacterium Polaromonas sp. Nea-C as a relevant barrier for atrazine biodegradation.
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Affiliation(s)
- Benno
N. Ehrl
- Institute
of Groundwater Ecology, Helmholtz Zentrum
München, Ingolstädter
Landstrasse 1, 85764 Neuherberg, Germany
| | - Mehdi Gharasoo
- Institute
of Groundwater Ecology, Helmholtz Zentrum
München, Ingolstädter
Landstrasse 1, 85764 Neuherberg, Germany
| | - Martin Elsner
- Institute
of Groundwater Ecology, Helmholtz Zentrum
München, Ingolstädter
Landstrasse 1, 85764 Neuherberg, Germany
- Chair
of Analytical Chemistry and Water Chemistry, Technical University of Munich, Marchioninistrasse 17, 81377 Munich, Germany
- E-mail: . Tel.: +49 89 2180-78232
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24
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Leitner S, Reichenauer TG, Watzinger A. Impact of sorption processes on PCE concentrations in organohalide-respiring aquifer sediment samples. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 615:1061-1069. [PMID: 29751409 DOI: 10.1016/j.scitotenv.2017.09.225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 09/20/2017] [Accepted: 09/21/2017] [Indexed: 06/08/2023]
Abstract
The evaluation of groundwater contaminant e.g. tetrachloroethene (PCE) degradation processes requires complete quantification of and pathway analysis of the groundwater contaminant under investigation. For example the reduction of PCE concentrations in the groundwater by unknown dissolution and/or sorption processes will impede interpretation of the fate and behaviour of such contaminants. In the present study PCE dissolution and sorption processes during anaerobic microbial degradation of chlorinated ethenes were investigated. For this purpose, microcosms were prepared using sediment samples from a PCE-contaminated aquifer, which in previous studies had demonstrated anaerobic organohalide respiration of PCE. Solid/water distribution coefficients (kd) of PCE were determined and validated by loss-on-ignition (LOI) and PCE sorption experiments. The determined kd magnitudes indicated methodological congruency, yielding values for sediment samples within a range of 1.15±0.02 to 5.93±0.34L·kg-1. The microcosm experiment showed lower PCE concentrations than expected, based on spiked PCE and observed anaerobic microbial degradation processes. Nevertheless the amount of PCE spike added was completely recovered albeit in the form of lower chlorinated metabolites. A delay due to dissolution processes was not responsible for this phenomenon. Sorption to sediments could only partially explain the reduction of PCE in the water phase. Accordingly, the results point to reversible sorption processes of PCE, possibly onto bacterial cell compartments and/or exopolymeric substances.
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Affiliation(s)
- Simon Leitner
- AIT Austrian Institute of Technology GmbH, Center for Energy, Environmental Resources and Technologies, Konrad-Lorenz-Straße 24, 3430 Tulln, Austria
| | - Thomas G Reichenauer
- AIT Austrian Institute of Technology GmbH, Center for Energy, Environmental Resources and Technologies, Konrad-Lorenz-Straße 24, 3430 Tulln, Austria
| | - Andrea Watzinger
- AIT Austrian Institute of Technology GmbH, Center for Energy, Environmental Resources and Technologies, Konrad-Lorenz-Straße 24, 3430 Tulln, Austria.
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25
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Sohn SY, Kuntze K, Nijenhuis I, Häggblom MM. Evaluation of carbon isotope fractionation during anaerobic reductive dehalogenation of chlorinated and brominated benzenes. CHEMOSPHERE 2018; 193:785-792. [PMID: 29175406 DOI: 10.1016/j.chemosphere.2017.11.089] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2017] [Revised: 11/15/2017] [Accepted: 11/18/2017] [Indexed: 06/07/2023]
Abstract
Compound specific stable isotope analysis (CSIA) has been established as a useful tool to evaluate in situ biodegradation. Here, CSIA was used to determine microbial dehalogenation of chloro- and bromobenzenes in microcosms derived from Hackensack River sediments. Gas chromatography-isotope ratio mass spectrometry (GC-IRMS) was used to measure carbon isotope fractionation during reductive dehalogenation of hexachlorobenzene (HCB), pentachlorobenzene (PeCB), 1,2,3,5-tetrachlorobenzene (TeCB), 1,2,3,5-tetrabromobenzene (TeBB), and 1,3,5-tribromobenzene (TriBB). Strong evidence of isotope fractionation coupled to dehalogenation was not observed in the substrate, possibly due to the low solubilities of the highly halogenated benzene substrates and a dilution of the isotope signal. Nonetheless, we could measure a depletion of the δ13C value in the dichlorobenzene product during dechlorination of HCB, the sequential depletion and enrichment of δ13C value for trichlorobenzene in TeCB dechlorinating cultures, and the enrichment of δ13C during debromination of TriBB. This indicates that a measurable isotope fractionation occurred during reductive dehalogenation of highly halogenated chloro- and bromobenzenes in aquatic sediments. Thus, although more quantitative measurements will be needed, the data suggests that CSIA may have application for monitoring in situ microbial reductive dehalogenation of highly halogenated benzenes.
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Affiliation(s)
- Seo Yean Sohn
- Department of Biochemistry and Microbiology, School of Environmental and Biological Sciences, Rutgers University, 76 Lipman Drive, New Brunswick, NJ 08901, USA
| | - Kevin Kuntze
- Department of Isotope Biogeochemistry, Helmholtz-Centre for Environmental Research - UFZ, Permoserstrasse 15, D-04318, Leipzig, Germany
| | - Ivonne Nijenhuis
- Department of Isotope Biogeochemistry, Helmholtz-Centre for Environmental Research - UFZ, Permoserstrasse 15, D-04318, Leipzig, Germany
| | - Max M Häggblom
- Department of Biochemistry and Microbiology, School of Environmental and Biological Sciences, Rutgers University, 76 Lipman Drive, New Brunswick, NJ 08901, USA.
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26
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Woods A, Kuntze K, Gelman F, Halicz L, Nijenhuis I. Variable dual carbon-bromine stable isotope fractionation during enzyme-catalyzed reductive dehalogenation of brominated ethenes. CHEMOSPHERE 2018; 190:211-217. [PMID: 28987410 DOI: 10.1016/j.chemosphere.2017.09.128] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 09/13/2017] [Accepted: 09/26/2017] [Indexed: 06/07/2023]
Abstract
The potential of compound-specific stable isotope analysis (CSIA) to characterize biotransformation of brominated organic compounds (BOCs) was assessed and compared to chlorinated analogues. Sulfurospirillum multivorans and Desulfitobacterium hafniense PCE-S catalyzed the dehalogenation of tribromoethene (TBE) to either vinyl bromide (VB) or ethene, respectively. Significantly lower isotope fractionation was observed for TBE dehalogenation by S. multivorans (εC = -1.3 ± 0.2‰) compared to D. hafniense (εC = -7.7 ± 1.5‰). However, higher fractionation was observed for dibromoethene (DBE) dehalogenation by S. multivorans (εC = -16.8 ± 1.8‰ and -21.2 ± 1.6‰ for trans- and cis-1,2- (DBE) respectively), compared to D. hafniense PCE-S (εC = -9.5 ± 1.2‰ and -14.5 ± 0.7‰ for trans-1,2-DBE and cis-1,2-DBE, respectively). Significant, but similar, bromine fractionation was observed for for S. multivorans (εBr = -0.53 ± 0.15‰, -1.03 ± 0.26‰, and -1.18 ± 0.13‰ for trans-1,2-DBE, cis-1,2-DBE and TBE, respectively) and D. hafniense PCE-S (εBr = -0.97 ± 0.28‰, -1.16 ± 0.36‰, and -1.34 ± 0.32‰ for cis-1,2-DBE, TBE and trans-1,2-DBE, respectively). Variable CBr dual-element slopes were estimated at Λ (εC/εBr) = 1.03 ± 0.2, 17.9 ± 5.8, and 29.9 ± 11.0 for S. multivorans debrominating TBE, cis-1,2-DBE and trans-1,2-DBE, respectively, and at 7.14 ± 1.6, 8.27 ± 3.7, and 8.92 ± 2.4 for D. hafniense PCE-S debrominating trans-1,2-DBE, TBE and cis-1,2-DBE, respectively. A high variability in isotope fractionation, which was substrate property related, was observed for S. multivorans but not D. hafniense, similar as observed for chlorinated ethenes, and may be due to rate-limiting steps preceding the bond-cleavage or differences in the reaction mechanism. Overall, significant isotope fractionation was observed and, therefore, CSIA can be applied to monitor the fate of brominated ethenes in the environment. Isotope effects differences, however, are not systematically comparable to chlorinated ethenes.
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Affiliation(s)
- Angela Woods
- Department for Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, D-04318, Leipzig, Germany
| | - Kevin Kuntze
- Department for Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, D-04318, Leipzig, Germany
| | - Faina Gelman
- Geological Survey of Israel, 30 Malkhe Israel St., Jerusalem, 95501, Israel
| | - Ludwik Halicz
- Geological Survey of Israel, 30 Malkhe Israel St., Jerusalem, 95501, Israel; Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw, Żwirki i Wigury 101, 02-089, Warsaw, Poland
| | - Ivonne Nijenhuis
- Department for Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, D-04318, Leipzig, Germany.
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27
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Leitner S, Berger H, Gorfer M, Reichenauer TG, Watzinger A. Isotopic effects of PCE induced by organohalide-respiring bacteria. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:24803-24815. [PMID: 28913587 DOI: 10.1007/s11356-017-0075-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 09/01/2017] [Indexed: 06/07/2023]
Abstract
Reductive dechlorination performed by organohalide-respiring bacteria (OHRB) enables the complete detoxification of certain emerging groundwater pollutants such as perchloroethene (PCE). Environmental samples from a contaminated site incubated in a lab-scale microcosm (MC) study enable documentation of such reductive dechlorination processes. As compound-specific isotope analysis is used to monitor PCE degradation processes, nucleic acid analysis-like 16S-rDNA analysis-can be used to determine the key OHRB that are present. This study applied both methods to laboratory MCs prepared from environmental samples to investigate OHRB-specific isotope enrichment at PCE dechlorination. This method linkage can enhance the understanding of isotope enrichment patterns of distinct OHRB, which further contribute to more accurate evaluation, characterisation and prospection of natural attenuation processes. Results identified three known OHRB genera (Dehalogenimonas, Desulfuromonas, Geobacter) in diverse abundance within MCs. One species of Dehalogenimonas was potentially involved in complete reductive dechlorination of PCE to ethene. Furthermore, the isotopic effects of PCE degradation were clustered and two isotope enrichment factors (ε) (- 11.6‰, - 1.7‰) were obtained. Notably, ε values were independent of degradation rates and kinetics, but did reflect the genera of the dechlorinating OHRB.
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Affiliation(s)
- Simon Leitner
- AIT Austrian Institute of Technology GmbH, Energy Department, Environmental Resources & Technologies, Konrad-Lorenz-Str. 24, 3430, Tulln, Austria
| | - Harald Berger
- AIT Austrian Institute of Technology GmbH, Health & Environment Department, Bioresources, Konrad-Lorenz-Str. 24, 3430, Tulln, Austria
| | - Markus Gorfer
- AIT Austrian Institute of Technology GmbH, Health & Environment Department, Bioresources, Konrad-Lorenz-Str. 24, 3430, Tulln, Austria
| | - Thomas G Reichenauer
- AIT Austrian Institute of Technology GmbH, Energy Department, Environmental Resources & Technologies, Konrad-Lorenz-Str. 24, 3430, Tulln, Austria
| | - Andrea Watzinger
- AIT Austrian Institute of Technology GmbH, Energy Department, Environmental Resources & Technologies, Konrad-Lorenz-Str. 24, 3430, Tulln, Austria.
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28
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Leitner S, Reichenauer TG, Watzinger A. Determination of carbon isotope enrichment factors of cis-dichloroethene after precursor amendment. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2017; 31:1699-1708. [PMID: 28805260 DOI: 10.1002/rcm.7957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 07/26/2017] [Accepted: 08/07/2017] [Indexed: 06/07/2023]
Abstract
RATIONALE Bacterial reductive dechlorination of the groundwater contaminant tetrachloroethene (PCE) involves the formation of lower chlorinated metabolites. Metabolites can be instantaneously formed and consumed in this sequential process; quantification and validation of their isotopic effects conventionally rely on separate laboratory microcosm studies. Here, we present an evaluation method enabling the determination of the carbon isotope enrichment factor (ε) for the intermediate cis-dichloroethene (cis-DCE) by a single laboratory microcosm study initially amending the precursor PCE only. METHODS Environmental samples harboring organohalide-respiring bacteria were incubated under anaerobic conditions and then successively and repeatedly amended with PCE and cis-DCE in two separate laboratory microcosm studies. Reductive dechlorination was monitored by analyzing liquid samples using Purge-and-Trap gas chromatography isotope ratio mass spectrometry GC/MS-C/IRMS. The prerequisites of the presented evaluation method are mass and δ-value balancing. The evaluation method was validated by agglomerative hierarchical classification of Rayleigh plot data points. RESULTS The sample-sensitive range of εcis-DCE extended from -10.6 ± 0.2‰ to -26.8 ± 0.6‰ (R2 ≥98%). The maximum standard deviations of εcis-DCE were ±1.8‰ for single microcosms, ±1.8‰ for replicates and ±1.0‰ for the compiled replicate data of PCE and cis-DCE amendments. A linear regression of the εcis-DCE for replicates obtained by each amendment study showed a slope of 95% (5 of the 7 data points are within a 95% confidence interval), demonstrating factor congruency and the practicability of the evaluation method. CONCLUSIONS We found metabolite degradation and formation to be sequential but also stepwise during bacterial reductive dechlorination. The stepwise phases of the degradation of the intermediate eliminate the impact of instantaneous precursor degradation. These stepwise sections were used to determine εcis-DCE -values. Our results showed the validity of εcis-DCE -values over a wide range at initial precursor degradation (PCE). The presented evaluation method could substantially decrease lab costs for microcosm studies designed for εcis-DCE determinations. Moreover, the results indicated that the evaluation method can be applied to other PCE-metabolites.
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Affiliation(s)
- Simon Leitner
- Center for Energy, Environmental Resources and Technologies, AIT Austrian Institute of Technology GmbH, Konrad-Lorenz-Straße 24, 3430, Tulln, Austria
| | - Thomas G Reichenauer
- Center for Energy, Environmental Resources and Technologies, AIT Austrian Institute of Technology GmbH, Konrad-Lorenz-Straße 24, 3430, Tulln, Austria
| | - Andrea Watzinger
- Center for Energy, Environmental Resources and Technologies, AIT Austrian Institute of Technology GmbH, Konrad-Lorenz-Straße 24, 3430, Tulln, Austria
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29
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Torrentó C, Palau J, Rodríguez-Fernández D, Heckel B, Meyer A, Domènech C, Rosell M, Soler A, Elsner M, Hunkeler D. Carbon and Chlorine Isotope Fractionation Patterns Associated with Different Engineered Chloroform Transformation Reactions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:6174-6184. [PMID: 28482655 DOI: 10.1021/acs.est.7b00679] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
To use compound-specific isotope analysis for confidently assessing organic contaminant attenuation in the environment, isotope fractionation patterns associated with different transformation mechanisms must first be explored in laboratory experiments. To deliver this information for the common groundwater contaminant chloroform (CF), this study investigated for the first time both carbon and chlorine isotope fractionation for three different engineered reactions: oxidative C-H bond cleavage using heat-activated persulfate, transformation under alkaline conditions (pH ∼ 12) and reductive C-Cl bond cleavage by cast zerovalent iron, Fe(0). Carbon and chlorine isotope fractionation values were -8 ± 1‰ and -0.44 ± 0.06‰ for oxidation, -57 ± 5‰ and -4.4 ± 0.4‰ for alkaline hydrolysis (pH 11.84 ± 0.03), and -33 ± 11‰ and -3 ± 1‰ for dechlorination, respectively. Carbon and chlorine apparent kinetic isotope effects (AKIEs) were in general agreement with expected mechanisms (C-H bond cleavage in oxidation by persulfate, C-Cl bond cleavage in Fe(0)-mediated reductive dechlorination and E1CB elimination mechanism during alkaline hydrolysis) where a secondary AKIECl (1.00045 ± 0.00004) was observed for oxidation. The different dual carbon-chlorine (Δδ13C vs Δδ37Cl) isotope patterns for oxidation by thermally activated persulfate and alkaline hydrolysis (17 ± 2 and 13.0 ± 0.8, respectively) vs reductive dechlorination by Fe(0) (8 ± 2) establish a base to identify and quantify these CF degradation mechanisms in the field.
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Affiliation(s)
- Clara Torrentó
- Centre for Hydrogeology and Geothermics, Université de Neuchâtel , 2000 Neuchâtel, Switzerland
- Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Martí Franques s/n, Universitat de Barcelona (UB) , 08028 Barcelona, Spain
| | - Jordi Palau
- Centre for Hydrogeology and Geothermics, Université de Neuchâtel , 2000 Neuchâtel, Switzerland
- Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Martí Franques s/n, Universitat de Barcelona (UB) , 08028 Barcelona, Spain
| | - Diana Rodríguez-Fernández
- Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Martí Franques s/n, Universitat de Barcelona (UB) , 08028 Barcelona, Spain
| | - Benjamin Heckel
- Institute of Groundwater Ecology, Helmholtz Zentrum München , 85764 Neuherberg, Germany
| | - Armin Meyer
- Institute of Groundwater Ecology, Helmholtz Zentrum München , 85764 Neuherberg, Germany
| | - Cristina Domènech
- Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Martí Franques s/n, Universitat de Barcelona (UB) , 08028 Barcelona, Spain
| | - Mònica Rosell
- Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Martí Franques s/n, Universitat de Barcelona (UB) , 08028 Barcelona, Spain
| | - Albert Soler
- Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Ciències de la Terra, Martí Franques s/n, Universitat de Barcelona (UB) , 08028 Barcelona, Spain
| | - Martin Elsner
- Institute of Groundwater Ecology, Helmholtz Zentrum München , 85764 Neuherberg, Germany
- Chair of Analytical Chemistry and Water Chemistry, Technical University of Munich , Marchioninistrasse 17, D-81377 Munich, Germany
| | - Daniel Hunkeler
- Centre for Hydrogeology and Geothermics, Université de Neuchâtel , 2000 Neuchâtel, Switzerland
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Palau J, Yu R, Hatijah Mortan S, Shouakar-Stash O, Rosell M, Freedman DL, Sbarbati C, Fiorenza S, Aravena R, Marco-Urrea E, Elsner M, Soler A, Hunkeler D. Distinct Dual C-Cl Isotope Fractionation Patterns during Anaerobic Biodegradation of 1,2-Dichloroethane: Potential To Characterize Microbial Degradation in the Field. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:2685-2694. [PMID: 28192987 DOI: 10.1021/acs.est.6b04998] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
This study investigates, for the first time, dual C-Cl isotope fractionation during anaerobic biodegradation of 1,2-dichloroethane (1,2-DCA) via dihaloelimination by Dehalococcoides and Dehalogenimonas-containing enrichment cultures. Isotopic fractionation of 1,2-DCA (εbulkC and εbulkCl) for Dehalococcoides (-33.0 ± 0.4‰ and -5.1 ± 0.1‰) and Dehalogenimonas-containing microcosms (-23 ± 2‰ and -12.0 ± 0.8‰) resulted in distinctly different dual element C-Cl isotope correlations (Λ = Δδ13C/Δδ37Cl ≈ εbulkC/εbulkCl), 6.8 ± 0.2 and 1.89 ± 0.02, respectively. Determined isotope effects and detected products suggest that the difference on the obtained Λ values for biodihaloelimination could be associated with a different mode of concerted bond cleavage rather than two different reaction pathways (i.e., stepwise vs concerted). Λ values of 1,2-DCA were, for the first time, determined in two field sites under reducing conditions (2.1 ± 0.1 and 2.2 ± 2.9). They were similar to the one obtained for the Dehalogenimonas-containing microcosms (1.89 ± 0.02) and very different from those reported for aerobic degradation pathways in a previous laboratory study (7.6 ± 0.1 and 0.78 ± 0.03). Thus, this study illustrates the potential of a dual isotope analysis to differentiate between aerobic and anaerobic biodegradation pathways of 1,2-DCA in the field and suggests that this approach might also be used to characterize dihaloelimination of 1,2-DCA by different bacteria, which needs to be confirmed in future studies.
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Affiliation(s)
- J Palau
- Centre for Hydrogeology and Geothermics, University of Neuchâtel , 2000 Neuchâtel, Switzerland
- Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Geologia, Universitat de Barcelona , Martí i Franquès s/n, 08028 Barcelona, Spain
- Institute of Environmental Assessment and Water Research (IDAEA), CSIC, Jordi Girona 18-26, 08034 Barcelona, Spain; Associated Unit: Hydrogeology Group (UPC-CSIC), Barcelona, Spain
| | - R Yu
- Department of Environmental Engineering and Earth Sciences, Clemson University , Clemson, South Carolina United States
| | - S Hatijah Mortan
- Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona , Carrer de les Sitges s/n, 08193 Bellaterra, Spain
| | - O Shouakar-Stash
- Department of Earth and Environmental Sciences, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada
- Isotope Tracer Technologies Inc., Waterloo, Ontario Canada N2 V 1Z5
| | - M Rosell
- Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Geologia, Universitat de Barcelona , Martí i Franquès s/n, 08028 Barcelona, Spain
| | - D L Freedman
- Department of Environmental Engineering and Earth Sciences, Clemson University , Clemson, South Carolina United States
| | - C Sbarbati
- Department of Earth Sciences, "Sapienza" University , P.le A. Moro 5, 00185 Rome, Italy
| | - S Fiorenza
- Remediation Engineering and Technology, BP America, Houston, Texas 77079, United States
| | - R Aravena
- Department of Earth and Environmental Sciences, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada
| | - E Marco-Urrea
- Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona , Carrer de les Sitges s/n, 08193 Bellaterra, Spain
| | - M Elsner
- Helmholtz Zentrum München, German Research Center for Environmental Health, D-85764 Neuherberg, Germany
| | - A Soler
- Grup de Mineralogia Aplicada i Geoquímica de Fluids, Departament de Mineralogia, Petrologia i Geologia Aplicada, Facultat de Geologia, Universitat de Barcelona , Martí i Franquès s/n, 08028 Barcelona, Spain
| | - D Hunkeler
- Centre for Hydrogeology and Geothermics, University of Neuchâtel , 2000 Neuchâtel, Switzerland
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Vogt C, Dorer C, Musat F, Richnow HH. Multi-element isotope fractionation concepts to characterize the biodegradation of hydrocarbons — from enzymes to the environment. Curr Opin Biotechnol 2016; 41:90-98. [DOI: 10.1016/j.copbio.2016.04.027] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 04/22/2016] [Accepted: 04/29/2016] [Indexed: 10/21/2022]
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32
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Nijenhuis I, Richnow HH. Stable isotope fractionation concepts for characterizing biotransformation of organohalides. Curr Opin Biotechnol 2016; 41:108-113. [DOI: 10.1016/j.copbio.2016.06.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 05/23/2016] [Accepted: 06/06/2016] [Indexed: 12/11/2022]
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Kuntze K, Kozell A, Richnow HH, Halicz L, Nijenhuis I, Gelman F. Dual Carbon-Bromine Stable Isotope Analysis Allows Distinguishing Transformation Pathways of Ethylene Dibromide. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:9855-9863. [PMID: 27526716 DOI: 10.1021/acs.est.6b01692] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The present study investigated dual carbon-bromine isotope fractionation of the common groundwater contaminant ethylene dibromide (EDB) during chemical and biological transformations, including aerobic and anaerobic biodegradation, alkaline hydrolysis, Fenton-like degradation, debromination by Zn(0) and reduced corrinoids. Significantly different correlation of carbon and bromine isotope fractionation (ΛC/Br) was observed not only for the processes following different transformation pathways, but also for abiotic and biotic processes with, the presumed, same formal chemical degradation mechanism. The studied processes resulted in a wide range of ΛC/Br values: ΛC/Br = 30.1 was observed for hydrolysis of EDB in alkaline solution; ΛC/Br between 4.2 and 5.3 were determined for dibromoelimination pathway with reduced corrinoids and Zn(0) particles; EDB biodegradation by Ancylobacter aquaticus and Sulfurospirillum multivorans resulted in ΛC/Br = 10.7 and 2.4, respectively; Fenton-like degradation resulted in carbon isotope fractionation only, leading to ΛC/Br ∞. Calculated carbon apparent kinetic isotope effects ((13)C-AKIE) fell with 1.005 to 1.035 within expected ranges according to the theoretical KIE, however, biotic transformations resulted in weaker carbon isotope effects than respective abiotic transformations. Relatively large bromine isotope effects with (81)Br-AKIE of 1.0012-1.002 and 1.0021-1.004 were observed for nucleophilic substitution and dibromoelimination, respectively, and reveal so far underestimated strong bromine isotope effects.
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Affiliation(s)
- Kevin Kuntze
- Department of Isotope Biogeochemistry, Helmholtz-Centre for Environmental Research - UFZ , Permoserstrasse 15, 04318 Leipzig, Germany
| | - Anna Kozell
- Geological Survey of Israel, 30 Malkhei Israel St., Jerusalem, 95501, Israel
| | - Hans H Richnow
- Department of Isotope Biogeochemistry, Helmholtz-Centre for Environmental Research - UFZ , Permoserstrasse 15, 04318 Leipzig, Germany
| | - Ludwik Halicz
- Geological Survey of Israel, 30 Malkhei Israel St., Jerusalem, 95501, Israel
- Faculty of Chemistry, Biological and Chemical Research Centre, University of Warsaw , 02-089 Warsaw, Poland
| | - Ivonne Nijenhuis
- Department of Isotope Biogeochemistry, Helmholtz-Centre for Environmental Research - UFZ , Permoserstrasse 15, 04318 Leipzig, Germany
| | - Faina Gelman
- Geological Survey of Israel, 30 Malkhei Israel St., Jerusalem, 95501, Israel
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Balaban N, Bernstein A, Gelman F, Ronen Z. Microbial degradation of the brominated flame retardant TBNPA by groundwater bacteria: laboratory and field study. CHEMOSPHERE 2016; 156:367-373. [PMID: 27183339 DOI: 10.1016/j.chemosphere.2016.04.127] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 04/10/2016] [Accepted: 04/30/2016] [Indexed: 06/05/2023]
Abstract
In the present study, the biodegradation of the brominated flame retardant tribromoneopentylalcohol (TBNPA) by a groundwater enrichment culture was investigated using a dual carbon ((13)C/(12)C)- bromine ((81)Br/(79)Br) stable isotope analysis. An indigenous aerobic bacterial consortium was enriched from the polluted groundwater underlying an industrial site in the northern Negev Desert, Israel, where TBNPA is an abundant pollutant. Aerobic biodegradation was shown to be rapid, with complete debromination within a few days, whereas anaerobic biodegradation was not observed. Biodegradation under aerobic conditions was accompanied by a significant carbon isotope effect with an isotopic enrichment factor of ɛCbulk = -8.8‰ ± 1.5‰, without any detectable bromine isotope fractionation. It was found that molecular oxygen is necessary for biodegradation to occur, suggesting an initial oxidative step. Based on these results, it was proposed that H abstraction from the C-H bond is the first step of TBNPA biodegradation under aerobic conditions, and that the C-H bond cleavage results in the formation of unstable intermediates, which are rapidly debrominated. A preliminary isotopic analysis of TBNPA in the groundwater underlying the industrial area revealed that there are no changes in the carbon and bromine isotope ratio values downstream of the contamination source. Considering that anoxic conditions prevail in the groundwater of the contaminated site, the lack of isotope shifts in TBNPA indicates the lack of TBNPA biodegradation in the groundwater, in accordance with our findings.
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Affiliation(s)
- Noa Balaban
- Department of Environmental Hydrology & Microbiology (EHM), The Zuckerberg Institute for Water Research (ZIWR), The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Israel.
| | - Anat Bernstein
- Department of Environmental Hydrology & Microbiology (EHM), The Zuckerberg Institute for Water Research (ZIWR), The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Israel.
| | - Faina Gelman
- Geological Survey of Israel, 30 Malkhei Israel St., Jerusalem 95501, Israel.
| | - Zeev Ronen
- Department of Environmental Hydrology & Microbiology (EHM), The Zuckerberg Institute for Water Research (ZIWR), The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Israel.
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Nijenhuis I, Kuntze K. Anaerobic microbial dehalogenation of organohalides — state of the art and remediation strategies. Curr Opin Biotechnol 2016; 38:33-8. [DOI: 10.1016/j.copbio.2015.11.009] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 11/03/2015] [Indexed: 11/26/2022]
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Musat F, Vogt C, Richnow HH. Carbon and Hydrogen Stable Isotope Fractionation Associated with the Aerobic and Anaerobic Degradation of Saturated and Alkylated Aromatic Hydrocarbons. J Mol Microbiol Biotechnol 2016; 26:211-26. [DOI: 10.1159/000442161] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Saturated hydrocarbons (alkanes) and alkylated aromatic hydrocarbons are abundant environmental compounds. Hydrocarbons are primarily removed from the environment by biodegradation, a process usually associated with moderate carbon and significant hydrogen isotope fractionation allowing monitoring of biodegradation processes in the environment. Here, we review the carbon and hydrogen stable isotope fractionation associated with the cleavage of C-H bonds at alkyl chains of hydrocarbons. Propane, <i>n</i>-butane and ethylbenzene were used as model components for alkyl moieties of aliphatic and aromatic hydrocarbons with emphasis on the cleavage of the C-H bond without the involvement of molecular oxygen. The carbon and hydrogen isotope fractionation factors were further used to explore the diagnostic potential for characterizing the mode of bond cleavage under oxic and anoxic conditions. Λ factors, calculated to correlate carbon and hydrogen fractionation, allowed to distinguish between aerobic and anaerobic biodegradation processes in the environment.
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