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Al-Fathi H, Koch M, Lorenz WG, Lechner U. Anaerobic degradation of 2,4,5-trichlorophenoxyacetic acid by enrichment cultures from freshwater sediments. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:34459-34467. [PMID: 31642015 DOI: 10.1007/s11356-019-06584-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 09/23/2019] [Indexed: 06/10/2023]
Abstract
The anaerobic biodegradation of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) was investigated using enrichment cultures from freshwater sediments at two different sites in the region of Halle, central Germany. 2,4,5-T and different organic acids or hydrogen were added as possible electron acceptor and electron donors, respectively. The primary enrichment cultures from Saale river sediment completely degraded 2,4,5-T to 3-chlorophenol (3-CP) (major product) and 3,4-dichlorophenol (3,4-DCP) during a 28-day incubation period. Subcultures showed ether cleavage of 2,4,5-T to 2,4,5-trichlorophenol and its stoichiometric dechlorination to 3-CP only in the presence of butyrate. In contrast, the primary enrichment culture from sediment of Posthorn pond dechlorinated 2,4,5-T to 2,5-dichlorophenoxyacetic acid (2,5-D), which, in the presence of butyrate, was degraded further to products such as 3,4-DCP, 2,5-DCP, and 3CP, indicating ether cleaving activities and subsequent dechlorination steps. Experiments with pure cultures of Dehalococcoides mccartyi and Desulfitobacterium hafniense demonstrated their specific dechlorination steps within the overall 2,4,5-T degradation pathways. The results indicate that the route and efficiency of anaerobic 2,4,5-T degradation in the environment depend heavily on the microorganisms present and the availability of slowly fermentable organic compounds.
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Affiliation(s)
- Hassan Al-Fathi
- Institute of Biology/Microbiology, Martin-Luther University Halle-Wittenberg, Halle, Germany
- Department Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Mandy Koch
- Institute of Chemistry/Food and Environmental Chemistry, Martin-Luther University Halle-Wittenberg, Halle, Germany
| | - Wilhelm G Lorenz
- Institute of Chemistry/Food and Environmental Chemistry, Martin-Luther University Halle-Wittenberg, Halle, Germany
| | - Ute Lechner
- Institute of Biology/Microbiology, Martin-Luther University Halle-Wittenberg, Halle, Germany.
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Lechner U, Türkowsky D, Dinh TTH, Al‐Fathi H, Schwoch S, Franke S, Gerlach M, Koch M, von Bergen M, Jehmlich N, Dang TCH. Desulfitobacterium contributes to the microbial transformation of 2,4,5-T by methanogenic enrichment cultures from a Vietnamese active landfill. Microb Biotechnol 2018; 11:1137-1156. [PMID: 30117290 PMCID: PMC6196390 DOI: 10.1111/1751-7915.13301] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 07/07/2018] [Indexed: 12/17/2022] Open
Abstract
The herbicide 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) was a major component of Agent Orange, which was used as a defoliant in the Vietnam War. Little is known about its degradation under anoxic conditions. Established enrichment cultures using soil from an Agent Orange bioremediation plant in southern Vietnam with pyruvate as potential electron donor and carbon source were shown to degrade 2,4,5-T via ether cleavage to 2,4,5-trichlorophenol (2,4,5-TCP), which was further dechlorinated to 3,4-dichlorophenol. Pyruvate was initially fermented to hydrogen, acetate and propionate. Hydrogen was then used as the direct electron donor for ether cleavage of 2,4,5-T and subsequent dechlorination of 2,4,5-TCP. 16S rRNA gene amplicon sequencing indicated the presence of bacteria and archaea mainly belonging to the Firmicutes, Bacteroidetes, Spirochaetes, Chloroflexi and Euryarchaeota. Desulfitobacterium hafniense was identified as the dechlorinating bacterium. Metaproteomics of the enrichment culture indicated higher protein abundances of 60 protein groups in the presence of 2,4,5-T. A reductive dehalogenase related to RdhA3 of D. hafniense showed the highest fold change, supporting its function in reductive dehalogenation of 2,4,5-TCP. Despite an ether-cleaving enzyme not being detected, the inhibition of ether cleavage but not of dechlorination, by 2-bromoethane sulphonate, suggested that the two reactions are catalysed by different organisms.
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Affiliation(s)
- Ute Lechner
- Institute of Biology/MicrobiologyMartin‐Luther University Halle‐WittenbergHalleGermany
| | - Dominique Türkowsky
- Department of Molecular Systems BiologyHelmholtz Centre for Environmental Research – UFZLeipzigGermany
| | - Thi Thu Hang Dinh
- Vietnamese Academy of Science and TechnologyInstitute of BiotechnologyHanoiVietnam
- Present address:
Vietnamese Academy of Science and TechnologyGraduate University of Science and TechnologyHanoiVietnam
| | - Hassan Al‐Fathi
- Institute of Biology/MicrobiologyMartin‐Luther University Halle‐WittenbergHalleGermany
| | - Stefan Schwoch
- Institute of Biology/MicrobiologyMartin‐Luther University Halle‐WittenbergHalleGermany
| | - Stefan Franke
- Institute of Biology/MicrobiologyMartin‐Luther University Halle‐WittenbergHalleGermany
| | | | - Mandy Koch
- Institute of Chemistry/Food and Environmental ChemistryMartin‐Luther University Halle‐WittenbergHalleGermany
| | - Martin von Bergen
- Department of Molecular Systems BiologyHelmholtz Centre for Environmental Research – UFZLeipzigGermany
| | - Nico Jehmlich
- Department of Molecular Systems BiologyHelmholtz Centre for Environmental Research – UFZLeipzigGermany
| | - Thi Cam Ha Dang
- Vietnamese Academy of Science and TechnologyInstitute of BiotechnologyHanoiVietnam
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Frková Z, Johansen A, de Jonge LW, Olsen P, Gosewinkel U, Bester K. Degradation and enantiomeric fractionation of mecoprop in soil previously exposed to phenoxy acid herbicides - New insights for bioremediation. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 569-570:1457-1465. [PMID: 27432728 DOI: 10.1016/j.scitotenv.2016.06.236] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 06/28/2016] [Accepted: 06/29/2016] [Indexed: 06/06/2023]
Abstract
Phenoxy acid-contaminated subsoils are common as a result of irregular disposal of residues and production wastes in the past. For enhancing in situ biodegradation at reducing conditions, biostimulation may be an effective option. Some phenoxy acids were marketed in racemic mixtures, and biodegradation rates may differ between enantiomers. Therefore, enantio-preferred degradation of mecoprop (MCPP) in soil was measured to get in-depth information on whether amendment with glucose (BOD equivalents as substrate for microbial growth) and nitrate (redox equivalents for oxidation) can stimulate bioremediation. The degradation processes were studied in soil sampled at different depths (3, 4.5 and 6m) at a Danish urban site with a history of phenoxy acid contamination. We observed preferential degradation of the R-enantiomer only under aerobic conditions in the soil samples from 3- and 6-m depth at environmentally relevant (nM) MCPP concentrations: enantiomer fraction (EF)<0.5. On the other hand, we observed preferential degradation of the S-enantiomer in all samples and treatments at elevated (μM) MCPP concentrations: EF>0.5. Three different microbial communities were discriminated by enantioselective degradation of MCPP: 1) aerobic microorganisms with little enantioselectivity, 2) aerobic microorganisms with R-selectivity and 3) anaerobic denitrifying organisms with S-selectivity. Glucose-amendment did not enhance MCPP degradation, while nitrate amendment enhanced the degradation of high concentrations of the herbicide.
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Affiliation(s)
- Zuzana Frková
- Department of Environmental Science, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark; Biology Centre, Czech Academy of Sciences, Branišovská 31, 37005, České Budějovice, Czech Republic
| | - Anders Johansen
- Department of Environmental Science, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | | | - Preben Olsen
- Department of Agroecology, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark
| | - Ulrich Gosewinkel
- Department of Environmental Science, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Kai Bester
- Department of Environmental Science, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark.
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García-Cruz U, Celis LB, Poggi H, Meraz M. Inhibitory concentrations of 2,4D and its possible intermediates in sulfate reducing biofilms. JOURNAL OF HAZARDOUS MATERIALS 2010; 179:591-595. [PMID: 20388582 DOI: 10.1016/j.jhazmat.2010.03.044] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Revised: 03/10/2010] [Accepted: 03/11/2010] [Indexed: 05/29/2023]
Abstract
Different concentrations of the herbicide 2,4-dichlorophenoxyacetic acid (2,4D) and its possible intermediates such as 2,4-dichlorophenol (2,4DCP), 4-chlorophenol (4CP), 2-chlorophenol (2CP) and phenol, were assayed to evaluate the inhibitory effect on sulfate and ethanol utilization in a sulfate reducing biofilm. Increasing concentrations of the chlorophenolic compounds showed an adverse effect on sulfate reduction rate and ethanol conversion to acetate, being the intermediate 2,4DCP most toxic than the herbicide. The monochlorophenol 4CP (600 ppm) caused the complete cessation of sulfate reduction and ethanol conversion. The ratio of the electron acceptor to the electron donor utilized as well as the sulfate utilization volumetric rates, diminished when chlorophenols and phenol concentrations were increased, pointing out to the inhibition of the respiratory process and electrons transfer. The difference found in the IC(50) values obtained was due to the chemical structure complexity of the phenolic compounds, the number of chlorine atoms as much as the chlorine atom position in the phenol ring. The IC(50) values (ppm) indicated that the acute inhibition on the biofilm was caused by 2,4DCP (17.4) followed by 2,4D (29.0), 2CP (99.8), 4CP (108.0) and phenol (143.8).
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Affiliation(s)
- Ulises García-Cruz
- Department of Biotechnology, Environmental Science and Technology, Universidad Autónoma Metropolitana-Iztapalapa, Ave. San Rafael Atlixco 186, Vicentina, 09340 DF, Mexico
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Mouttaki H, Nanny MA, McInerney MJ. Use of benzoate as an electron acceptor by Syntrophus aciditrophicus grown in pure culture with crotonate. Environ Microbiol 2008; 10:3265-74. [PMID: 18707608 DOI: 10.1111/j.1462-2920.2008.01716.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In methanogenic environments, the main fate of benzoate is its oxidization to acetate, H(2) and CO(2) by syntrophic associations of hydrogen-producing benzoate degraders and hydrogen-using methanogens. Here, we report the use of benzoate as an electron acceptor. Pure cultures of S. aciditrophicus simultaneously degraded crotonate and benzoate when both substrates were present. The growth rate was 0.007 h(-1) with crotonate and benzoate present compared with 0.025 h(-1) with crotonate alone. After 8 days of incubation, 4.12 +/- 0.50 mM of cyclohexane carboxylate and 8.40 +/- 0.61 mM of acetate were formed and 4.0 +/- 0.04 mM of benzoate and 4.8 +/- 0.5 mM of crotonate were consumed. The molar growth yield was 22.7 +/- 2.1 g (dry wt) of cells per mol of crotonate compared with about 14.0 +/- 0.1 g (dry wt) of cells per mol of crotonate when S. aciditrophicus was grown with crotonate alone. Cultures grown with [ring-(13)C]-benzoate and unlabelled crotonate initially formed [ring-(13)C]-labelled cyclohexane carboxylate. No (13)C-labelled acetate was detected. In addition to cyclohexane carboxylate, (13)C-labelled cyclohex-1-ene carboxylate was detected as an intermediate. Once almost all of the benzoate was gone, carbon isotopic analyses showed that cyclohexane carboxylate was formed from both labelled and non-labelled metabolites. Glutarate and pimelate were also detected at this time and carbon isotopic analyses showed that each was made from a mixture labelled and non-labelled metabolites. The increase in molar growth yield with crotonate and benzoate and the formation of [ring-(13)C]-cyclohexane carboxylate from [ring-(13)C]-benzoate in the presence of crotonate are consistent with benzoate serving as an electron acceptor.
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Affiliation(s)
- Housna Mouttaki
- Departments of Botany and Microbiology, University of Oklahoma, Norman, OK, USA
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Reitzel LA, Tuxen N, Ledin A, Bjerg PL. Can degradation products be used as documentation for natural attenuation of phenoxy acids in groundwater? ENVIRONMENTAL SCIENCE & TECHNOLOGY 2004; 38:457-67. [PMID: 14750720 DOI: 10.1021/es030039e] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In situ indicators of degradation are important tools in the demonstration of natural attenuation. A literature survey on the production history of phenoxy acids and degradation pathways has shown that metabolites of phenoxy acid herbicides also are impurities in the herbicide products, making the bare presence of these compounds useless as in situ indicators. These impurities can make up more than 30% of the herbicides. Degradation of phenoxy acids was demonstrated in microcosm experiments using groundwater and sediment contaminated with MCPP, dichlorprop, and related compounds such as other phenoxypropionic acids and chlorophenols. Field observations at two phenoxy acid-contaminated sites showed the occurrence of several impurities including metabolites in the groundwater. Neither the microcosm experiments nor the field observations verified that metabolites were actually produced or accumulated in situ. However, it was demonstrated that the impurity/parent herbicide ratios can be useful in situ indicators of degradation.
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Affiliation(s)
- Lotte A Reitzel
- Environment & Resources DTU, Technical University of Denmark, Building 115, Bygningstorvet, DK-2800 Kgs. Lyngby, Denmark.
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Mormile MR, Gurijala KR, Robinson JA, McInerney MJ, Suflita JM. The importance of hydrogen in landfill fermentations. Appl Environ Microbiol 1996; 62:1583-8. [PMID: 16535310 PMCID: PMC1388848 DOI: 10.1128/aem.62.5.1583-1588.1996] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Forty-two samples taken from two landfills were monitored for CH(inf4) production and apparent steady-state H(inf2) concentration. The rates of methanogenesis in these samples ranged from below the detection limit to 1,900 (mu)mol kg (dry weight)(sup-1) day(sup-1), and the median steady-state hydrogen concentration was 1.4 (mu)M in one landfill and 5.2 (mu)M in the other. To further investigate the relationship between hydrogen concentration and methanogenesis, a subset of seven landfill samples was selected on basis of their rates of CH(inf4) production, H(inf2) concentrations, sample pHs, and moisture contents. Samples with H(inf2) concentrations of <20 nM had relatively small amounts of volatile fatty acids (VFAs) (undetectable to 18.6 mmol of VFA kg [dry weight](sup-1)), while samples with H(inf2) concentrations of >100 nM had relatively high VFA levels (133 to 389 mmol of VFA kg [dry weight](sup-1)). Samples with high H(inf2) and VFA contents had relatively low pH values (<=6.3). However, methanogenic and syntrophic bacteria were present in all samples, so the lack of methanogenesis in some samples was not due to a lack of suitable inocula. The low rates of methanogenesis in these samples were probably due to inhibitory effects of low pH and VFA accumulation, resulting from a thermodynamic uncoupling of fatty acid oxidation. As in other anaerobic ecosystems, H(inf2) is a critical intermediate that may be used to monitor the status of landfill fermentations.
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Wrenn BA, Rittmann BE. A model for the effects of primary substrates on the kinetics of reductive dehalogenation. Biodegradation 1995. [DOI: 10.1007/bf00695260] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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