1
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Mohana Rangan S, Rao S, Robles A, Mouti A, LaPat-Polasko L, Lowry GV, Krajmalnik-Brown R, Delgado AG. Decoupling Fe 0 Application and Bioaugmentation in Space and Time Enables Microbial Reductive Dechlorination of Trichloroethene to Ethene: Evidence from Soil Columns. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:4167-4179. [PMID: 36866930 PMCID: PMC10018760 DOI: 10.1021/acs.est.2c06433] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 12/28/2022] [Accepted: 02/14/2023] [Indexed: 06/06/2023]
Abstract
Fe0 is a powerful chemical reductant with applications for remediation of chlorinated solvents, including tetrachloroethene and trichloroethene. Its utilization efficiency at contaminated sites is limited because most of the electrons from Fe0 are channeled to the reduction of water to H2 rather than to the reduction of the contaminants. Coupling Fe0 with H2-utilizing organohalide-respiring bacteria (i.e., Dehalococcoides mccartyi) could enhance trichloroethene conversion to ethene while maximizing Fe0 utilization efficiency. Columns packed with aquifer materials have been used to assess the efficacy of a treatment combining in space and time Fe0 and aD. mccartyi-containing culture (bioaugmentation). To date, most column studies documented only partial conversion of the solvents to chlorinated byproducts, calling into question the feasibility of Fe0 to promote complete microbial reductive dechlorination. In this study, we decoupled the application of Fe0 in space and time from the addition of organic substrates andD. mccartyi-containing cultures. We used a column containing soil and Fe0 (at 15 g L-1 in porewater) and fed it with groundwater as a proxy for an upstream Fe0 injection zone dominated by abiotic reactions and biostimulated/bioaugmented soil columns (Bio-columns) as proxies for downstream microbiological zones. Results showed that Bio-columns receiving reduced groundwater from the Fe0-column supported microbial reductive dechlorination, yielding up to 98% trichloroethene conversion to ethene. The microbial community in the Bio-columns established with Fe0-reduced groundwater also sustained trichloroethene reduction to ethene (up to 100%) when challenged with aerobic groundwater. This study supports a conceptual model where decoupling the application of Fe0 and biostimulation/bioaugmentation in space and/or time could augment microbial trichloroethene reductive dechlorination, particularly under oxic conditions.
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Affiliation(s)
- Srivatsan Mohana Rangan
- School
of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Biodesign
Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287, United States
- Center
for Bio-Mediated and Bio-Inspired Geotechnics (CBBG), Arizona State University, Tempe, Arizona 85281, United States
- Biodesign
Center for Health Through Microbiomes, Arizona
State University, Tempe, Arizona 85287, United States
| | - Shefali Rao
- School
of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Biodesign
Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287, United States
- Center
for Bio-Mediated and Bio-Inspired Geotechnics (CBBG), Arizona State University, Tempe, Arizona 85281, United States
| | - Aide Robles
- School
of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Biodesign
Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287, United States
- Center
for Bio-Mediated and Bio-Inspired Geotechnics (CBBG), Arizona State University, Tempe, Arizona 85281, United States
| | - Aatikah Mouti
- Biodesign
Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287, United States
| | | | - Gregory V. Lowry
- Center
for Environmental Implications of Nanotechnology (CEINT), Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
- Department
of Civil & Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Rosa Krajmalnik-Brown
- School
of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Biodesign
Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287, United States
- Center
for Bio-Mediated and Bio-Inspired Geotechnics (CBBG), Arizona State University, Tempe, Arizona 85281, United States
- Biodesign
Center for Health Through Microbiomes, Arizona
State University, Tempe, Arizona 85287, United States
| | - Anca G. Delgado
- School
of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Biodesign
Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287, United States
- Center
for Bio-Mediated and Bio-Inspired Geotechnics (CBBG), Arizona State University, Tempe, Arizona 85281, United States
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2
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Reino C, Ding C, Adrian L. Continuous cultivation of Dehalococcoides mccartyi with brominated tyrosine avoids toxic byproducts and gives tight reactor control. WATER RESEARCH 2023; 229:119396. [PMID: 36463679 DOI: 10.1016/j.watres.2022.119396] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 11/18/2022] [Accepted: 11/18/2022] [Indexed: 06/17/2023]
Abstract
Dehalococcoides mccartyi strain CBDB1 is a strictly anaerobic organohalide-respiring bacterium with strong application potential to remediate aquifers and soils contaminated with halogenated aromatics. To date, cultivation of strain CBDB1 has mostly been done in bottles or fed-batch reactors. Challenges with such systems include low biomass yield and difficulties in controlling the growth conditions. Here, we report the cultivation of planktonic D. mccartyi strain CBDB1 in a continuous stirring tank reactor (CSTR) that led to high cell densities (∼8 × 108 cells mL-1) and dominance of strain CBDB1. The reactor culture received acetate, hydrogen, and the brominated amino acid D- or L-3,5-dibromotyrosine as substrates. Both D- and L-3,5-dibromotyrosine were utilized as respiratory electron acceptors and are promising for biomass production due to their decent solubility in water and the formation of a non-toxic debromination product, tyrosine. By monitoring headspace pressure decrease which is indicative of hydrogen consumption, the organohalide respiration rate was followed in real time. Proteomics analyses revealed that the reductive dehalogenase CbdbA238 was highly expressed with both D- and L-3,5-dibromotyrosine, while other reductive dehalogenases including those that were previously suggested to be constitutively expressed, were repressed. Denaturing gradient gel electrophoresis (DGGE) of amplified 16S rRNA genes indicated that the majority of cells in the community belonged to the Dehalococcoides although the CSTR was operated under non-sterile conditions. Hence, tightly controlled CSTR cultivation of Dehalococcoides opens novel options to improve biomass production for bioaugmentation and for advanced biochemical studies.
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Affiliation(s)
- Clara Reino
- Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Biotechnology, Permoserstraße 15, 04318, Leipzig, Germany
| | - Chang Ding
- Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Biotechnology, Permoserstraße 15, 04318, Leipzig, Germany.
| | - Lorenz Adrian
- Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Biotechnology, Permoserstraße 15, 04318, Leipzig, Germany; Chair of Geobiotechnology, Technische Universität Berlin, Ackerstraße 76, 13355, Berlin, Germany
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3
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Miranda EM, Severson C, Reep JK, Hood D, Hansen S, Santisteban L, Hamdan N, Delgado AG. Continuous-mode acclimation and operation of lignocellulosic sulfate-reducing bioreactors for enhanced metal immobilization from acidic mining-influenced water. JOURNAL OF HAZARDOUS MATERIALS 2022; 425:128054. [PMID: 34986575 DOI: 10.1016/j.jhazmat.2021.128054] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/22/2021] [Accepted: 12/07/2021] [Indexed: 06/14/2023]
Abstract
Lignocellulosic sulfate-reducing bioreactors are an inexpensive passive approach for treatment of mining-influenced water (MIW). Typically, microbial community acclimation to MIW involves bioreactor batch-mode operation to initiate lignocellulose hydrolysis and fermentation and provide electron donors for sulfate-reducing bacteria. However, batch-mode operation could significantly prolong bioreactor start-up times (up to several months) and select for slow-growing microorganisms. In this study we assessed the feasibility of bioreactor continuous-mode acclimation to MIW (pH 2.5, 6.5 mM SO42-, 18 metal(loid)s) as an alternate start-up method. Results showed that bioreactors with spent brewing grains and sugarcane bagasse achieved acclimation in continuous mode at hydraulic retention times (HRTs) of 7-12-d within 16-22 days. During continuous-mode acclimation, extensive SO42- reduction (80 ± 20% -91 ± 3%) and > 98% metal(loid) removal was observed. Operation at a 3-d HRT further yielded a metal(loid) removal of 97.5 ± 1.3 -98.8 ± 0.9% until the end of operation. Sulfate-reducing microorganisms were detected closer to the influent in the spent brewing grains bioreactors, and closer to the effluent in the sugarcane bagasse bioreactors, giving insight as to where SO42- reduction was occurring. Results strongly support that a careful selection of lignocellulose and bioreactor operating parameters can bypass typical batch-mode acclimation, shortening bioreactor start-up times and promoting effective MIW metal(loid) immobilization and treatment.
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Affiliation(s)
- Evelyn M Miranda
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, 1001 S McAllister Ave, Tempe, AZ 85287, United States; Center for Bio-mediated & Bio-inspired Geotechnics, Arizona State University, 425 E University Dr, Tempe, AZ 85281, United States; School for Engineering of Matter, Transport and Energy, Arizona State University, 501 E Tyler Mall, Tempe, AZ 85281, United States
| | - Carli Severson
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, 1001 S McAllister Ave, Tempe, AZ 85287, United States; Center for Bio-mediated & Bio-inspired Geotechnics, Arizona State University, 425 E University Dr, Tempe, AZ 85281, United States
| | - Jeffrey K Reep
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, 1001 S McAllister Ave, Tempe, AZ 85287, United States; Center for Bio-mediated & Bio-inspired Geotechnics, Arizona State University, 425 E University Dr, Tempe, AZ 85281, United States; School of Sustainable Engineering and the Built Environment, Arizona State University, 660 S College Ave, Tempe, AZ 85281, United States
| | - Daniel Hood
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, 1001 S McAllister Ave, Tempe, AZ 85287, United States; Center for Bio-mediated & Bio-inspired Geotechnics, Arizona State University, 425 E University Dr, Tempe, AZ 85281, United States
| | - Shane Hansen
- Freeport-McMoRan Inc., 800 E Pima Mine Rd, Sahuarita, AZ 85629, United States
| | - Leonard Santisteban
- Freeport-McMoRan Inc., 800 E Pima Mine Rd, Sahuarita, AZ 85629, United States
| | - Nasser Hamdan
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, 1001 S McAllister Ave, Tempe, AZ 85287, United States; Center for Bio-mediated & Bio-inspired Geotechnics, Arizona State University, 425 E University Dr, Tempe, AZ 85281, United States; School of Sustainable Engineering and the Built Environment, Arizona State University, 660 S College Ave, Tempe, AZ 85281, United States
| | - Anca G Delgado
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, 1001 S McAllister Ave, Tempe, AZ 85287, United States; Center for Bio-mediated & Bio-inspired Geotechnics, Arizona State University, 425 E University Dr, Tempe, AZ 85281, United States; School of Sustainable Engineering and the Built Environment, Arizona State University, 660 S College Ave, Tempe, AZ 85281, United States.
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4
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Chen WY, Wu JH. Microbiome composition resulting from different substrates influences trichloroethene dechlorination performance. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 303:114145. [PMID: 34844052 DOI: 10.1016/j.jenvman.2021.114145] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 11/05/2021] [Accepted: 11/20/2021] [Indexed: 06/13/2023]
Abstract
Hydrogen-releasing substrates can stimulate the reductive dechlorination of trichloroethene (TCE) mediated by organohalide-respiring bacteria (OHRB) at contaminated sites. However, how the substrate affects microbiome assembly and the accompanying influences on the growth of OHRB and reductive TCE dechlorination remains unclear. We evaluated the effects of microbial community structures and potential functions on the reductive dechlorination of TCE in three anaerobic reactors with acetate, soybean oil, or molasses as the substrate and no cobalamin or amino acid supplementation. The molasses-fed reactor exhibited superior performance and dechlorination of TCE loadings to ethene, and the oil-fed reactor exhibited a high growth rate of the key OHRB, Dehalococcoides. This finding suggests an effect of the substrate on reductive dechlorination and the growth of Dehalococcoides. The three reactors developed distinct microbial community structures and the predicted metagenomes were distinguished on the basis of vitamin and amino acid metabolisms as well as fermentation pathways. In addition to the diversified hydrogen-producing pathways, the molasses-induced microbiome exhibited high potential to synthesize the cobalamin, which may account for its high Dehalococcoides activity and thus effective dechlorination performance. The substrate dependence of microbiomes may provide insight into strategies of exogenous amino acid supplementation to benefit Dehalococcoides growth. This study adds novel insight into the interplay of hydrogen-releasing substrates and OHRB. The results may contribute to the development of tailored and cost-effective management for the reductive dechlorination of chlorinated solvents in bioremediation.
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Affiliation(s)
- Wei-Yu Chen
- Department of Environmental Engineering, National Cheng Kung University, Taiwan; Center of Microbiome Science and Technology, National Cheng Kung University, Taiwan
| | - Jer-Horng Wu
- Department of Environmental Engineering, National Cheng Kung University, Taiwan.
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5
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Robles A, Yellowman TL, Joshi S, Mohana Rangan S, Delgado AG. Microbial Chain Elongation and Subsequent Fermentation of Elongated Carboxylates as H 2-Producing Processes for Sustained Reductive Dechlorination of Chlorinated Ethenes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:10398-10410. [PMID: 34283573 DOI: 10.1021/acs.est.1c01319] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In situ anaerobic groundwater bioremediation of trichloroethene (TCE) to nontoxic ethene is contingent on organohalide-respiring Dehalococcoidia, the most common strictly hydrogenotrophic Dehalococcoides mccartyi (D. mccartyi). The H2 requirement for D. mccartyi is fulfilled by adding various organic substrates (e.g., lactate, emulsified vegetable oil, and glucose/molasses), which require fermenting microorganisms to convert them to H2. The net flux of H2 is a crucial controlling parameter in the efficacy of bioremediation. H2 consumption by competing microorganisms (e.g., methanogens and homoacetogens) can diminish the rates of reductive dechlorination or stall the process altogether. Furthermore, some fermentation pathways do not produce H2 or having H2 as a product is not always thermodynamically favorable under environmental conditions. Here, we report on a novel application of microbial chain elongation as a H2-producing process for reductive dechlorination. In soil microcosms bioaugmented with dechlorinating and chain-elongating enrichment cultures, near stoichiometric conversion of TCE (0.07 ± 0.01, 0.60 ± 0.03, and 1.50 ± 0.20 mmol L-1 added sequentially) to ethene was achieved when initially stimulated by chain elongation of acetate and ethanol. Chain elongation initiated reductive dechlorination by liberating H2 in the conversion of acetate and ethanol to butyrate and caproate. Syntrophic fermentation of butyrate, a chain-elongation product, to H2 and acetate further sustained the reductive dechlorination activity. Methanogenesis was limited during TCE dechlorination in soil microcosms and absent in transfer cultures fed with chain-elongation substrates. This study provides critical fundamental knowledge toward the feasibility of chlorinated solvent bioremediation based on microbial chain elongation.
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Affiliation(s)
- Aide Robles
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, 1001 S. McAllister Ave., Tempe, Arizona 85287, United States
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Engineering Research Center for Bio-mediated and Bio-inspired Geotechnics, Arizona State University, Tempe, Arizona 85281, United States
| | - Theodora L Yellowman
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, 1001 S. McAllister Ave., Tempe, Arizona 85287, United States
- Engineering Research Center for Bio-mediated and Bio-inspired Geotechnics, Arizona State University, Tempe, Arizona 85281, United States
| | - Sayalee Joshi
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, 1001 S. McAllister Ave., Tempe, Arizona 85287, United States
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Engineering Research Center for Bio-mediated and Bio-inspired Geotechnics, Arizona State University, Tempe, Arizona 85281, United States
| | - Srivatsan Mohana Rangan
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, 1001 S. McAllister Ave., Tempe, Arizona 85287, United States
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Engineering Research Center for Bio-mediated and Bio-inspired Geotechnics, Arizona State University, Tempe, Arizona 85281, United States
| | - Anca G Delgado
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, 1001 S. McAllister Ave., Tempe, Arizona 85287, United States
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Engineering Research Center for Bio-mediated and Bio-inspired Geotechnics, Arizona State University, Tempe, Arizona 85281, United States
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6
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Joshi S, Robles A, Aguiar S, Delgado AG. The occurrence and ecology of microbial chain elongation of carboxylates in soils. THE ISME JOURNAL 2021; 15:1907-1918. [PMID: 33558687 PMCID: PMC8245554 DOI: 10.1038/s41396-021-00893-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 12/14/2020] [Accepted: 01/13/2021] [Indexed: 01/30/2023]
Abstract
Chain elongation is a growth-dependent anaerobic metabolism that combines acetate and ethanol into butyrate, hexanoate, and octanoate. While the model microorganism for chain elongation, Clostridium kluyveri, was isolated from a saturated soil sample in the 1940s, chain elongation has remained unexplored in soil environments. During soil fermentative events, simple carboxylates and alcohols can transiently accumulate up to low mM concentrations, suggesting in situ possibility of microbial chain elongation. Here, we examined the occurrence and microbial ecology of chain elongation in four soil types in microcosms and enrichments amended with chain elongation substrates. All soils showed evidence of chain elongation activity with several days of incubation at high (100 mM) and environmentally relevant (2.5 mM) concentrations of acetate and ethanol. Three soils showed substantial activity in soil microcosms with high substrate concentrations, converting 58% or more of the added carbon as acetate and ethanol to butyrate, butanol, and hexanoate. Semi-batch enrichment yielded hexanoate and octanoate as the most elongated products and microbial communities predominated by C. kluyveri and other Firmicutes genera not known to undergo chain elongation. Collectively, these results strongly suggest a niche for chain elongation in anaerobic soils that should not be overlooked in soil microbial ecology studies.
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Affiliation(s)
- Sayalee Joshi
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ, USA
| | - Aide Robles
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ, USA
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe, AZ, USA
- Engineering Research Center for Bio-mediated and Bio-inspired Geotechnics (CBBG), Arizona State University, Tempe, AZ, USA
| | - Samuel Aguiar
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe, AZ, USA
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Anca G Delgado
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, AZ, USA.
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe, AZ, USA.
- Engineering Research Center for Bio-mediated and Bio-inspired Geotechnics (CBBG), Arizona State University, Tempe, AZ, USA.
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7
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Luo YH, Zhou C, Bi Y, Long X, Wang B, Tang Y, Krajmalnik-Brown R, Rittmann BE. Long-Term Continuous Co-reduction of 1,1,1-Trichloroethane and Trichloroethene over Palladium Nanoparticles Spontaneously Deposited on H 2-Transfer Membranes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:2057-2066. [PMID: 33236898 DOI: 10.1021/acs.est.0c05217] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
1,1,1-Trichloroethane (1,1,1-TCA) and trichloroethene (TCE) are common recalcitrant contaminants that coexist in groundwater. H2-induced reduction over precious-metal catalysts has proven advantageous, but its application to long-term continuous treatment has been limited due to poor H2-transfer efficiency and catalyst loss. Furthermore, catalytic reductions of aqueous 1,1,1-TCA alone or concomitant with TCE catalytic co-reductions are unstudied. Here, we investigated 1,1,1-TCA and TCE co-reduction using palladium nanoparticle (PdNP) catalysts spontaneously deposited on H2-transfer membranes that allow efficient H2 supply on demand in a bubble-free form. The catalytic activities for 1,1,1-TCA and TCE reductions reached 9.9 and 11 L/g-Pd/min, values significantly greater than that reported for other immobilized-PdNP systems. During 90 day continuous operation, removals were up to 95% for 1,1,1-TCA and 99% for TCE. The highest steady-state removal fluxes were 1.5 g/m2/day for 1,1,1-TCA and 1.7 g/m2/day for TCE. The major product was nontoxic ethane (94% selectivity). Only 4% of the originally deposited PdNPs were lost over 90 days of continuous operation. Documenting long-term continuous Pd-catalyzed dechlorination at high surface loading with minimal loss of the catalyst mass or activity, this work expands understanding of and provides a foundation for sustainable catalytic removal of co-existing chlorinated solvents.
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Affiliation(s)
- Yi-Hao Luo
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe 85287-5701, Arizona, United States
| | - Chen Zhou
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe 85287-5701, Arizona, United States
| | - Yuqiang Bi
- Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, Arizona State University, Tempe 85287-5701, Arizona, United States
| | - Xiangxing Long
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe 85287-5701, Arizona, United States
- Nanosystems Engineering Research Center for Nanotechnology-Enabled Water Treatment, Arizona State University, Tempe 85287-5701, Arizona, United States
| | - Boya Wang
- Department of Civil and Environmental Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee 32306-1058, Florida, United States
| | - Youneng Tang
- Department of Civil and Environmental Engineering, FAMU-FSU College of Engineering, Florida State University, Tallahassee 32306-1058, Florida, United States
| | - Rosa Krajmalnik-Brown
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe 85287-5701, Arizona, United States
| | - Bruce E Rittmann
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe 85287-5701, Arizona, United States
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8
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Rangan SM, Mouti A, LaPat-Polasko L, Lowry GV, Krajmalnik-Brown R, Delgado AG. Synergistic Zerovalent Iron (Fe 0) and Microbiological Trichloroethene and Perchlorate Reductions Are Determined by the Concentration and Speciation of Fe. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:14422-14431. [PMID: 33151674 DOI: 10.1021/acs.est.0c05052] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Trichloroethene (TCE) and perchlorate (ClO4-) are cocontaminants at multiple Superfund sites. Fe0 is often used during TCE bioremediation with Dehalococcoides mccartyi to establish anoxic conditions in the aquifer. However, the synergy between Fe0 abiotic reactions and microbiological TCE and ClO4- reductions is poorly understood and seldom addressed in the literature. Here, we investigated the effects of Fe0 and its oxidation product, Fe2+, at field-relevant concentrations in promoting microbial TCE and ClO4- reductions. Using semibatch microcosms with a Superfund site soil and groundwater, we showed that the high Fe0 concentration (16.5 g L-1) expected during Fe0in situ injection mostly yielded TCE abiotic reduction to ethene/ethane. However, such concentrations obscured dechlorination by D. mccartyi, impeded ClO4- reduction, and enhanced SO42- reduction and methanogenesis. Fe2+ at 0.25 g L-1 substantially delayed conversion of TCE to ethene when compared to no-Fe controls. A low concentration of aged-Fe0 synergistically promoted microbiological TCE dechlorination to ethene while achieving complete ClO4- reduction. Collectively, these results illustrate scenarios relevant at or downstream of Fe0 injection zones when Fe0 is used to facilitate microbial dechlorination. Results also underscore the potential detrimental effects of Fe0 and bioaugmentation cultures coinjection for in situ treatment of chlorinated ethenes and ClO4-.
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Affiliation(s)
- Srivatsan Mohana Rangan
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287, United States
- Center for Bio-mediated and Bio-inspired Geotechnics (CBBG), Arizona State University, Tempe, Arizona 85281, United States
| | - Aatikah Mouti
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287, United States
| | | | - Gregory V Lowry
- Center for Environmental Implications of Nanotechnology (CEINT) Durham, North Carolina 27708, United States
- Department of Civil & Environmental Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Rosa Krajmalnik-Brown
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287, United States
- Center for Bio-mediated and Bio-inspired Geotechnics (CBBG), Arizona State University, Tempe, Arizona 85281, United States
| | - Anca G Delgado
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona 85287, United States
- Center for Bio-mediated and Bio-inspired Geotechnics (CBBG), Arizona State University, Tempe, Arizona 85281, United States
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9
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Zhao S, Rogers MJ, He J. Abundance of organohalide respiring bacteria and their role in dehalogenating antimicrobials in wastewater treatment plants. WATER RESEARCH 2020; 181:115893. [PMID: 32502751 DOI: 10.1016/j.watres.2020.115893] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 03/25/2020] [Accepted: 04/26/2020] [Indexed: 06/11/2023]
Abstract
Anthropogenic organohalide contaminants present in wastewater treatment plants (WWTPs) often remain untreated and can be discharged into the environment. Although organohalide respiring bacteria (OHRB) contribute to the elimination of anthropogenic organohalides in natural anaerobic environments, reductive dehalogenation by OHRB in mainstream WWTPs remains poorly understood. In this study, we quantified OHRB during a long-term operation of a municipal WWTP with short hydraulic and sludge retention times (3 h and 1.5-5 days, respectively). The obligate OHRB were detected at high levels (averaging 2.56 ± 1.73 × 107 and 3.11 ± 1.16 × 107 16S rRNA gene copies/ml MLSS sludge in anoxic and aerobic zones, respectively) over the entire sampling period and throughout the wastewater treatment train. Microcosms derived from mainstream activated sludge contained an unidentified member of the Dehalococcoides genus that metabolically dechlorinated triclosan, used as a representative emerging organohalide antimicrobial, to diclosan, suggesting the potential of anaerobic degradation of emerging contaminants in WWTPs. To further understand the mechanisms for such antimicrobials' removal, an investigation of dechlorination of triclosan by Dehalococcoides strains was conducted. Dechlorination of environmentally relevant concentrations of triclosan to diclosan was observed in Dehalococcoides mccartyi strain CG1, yielding 4.59 ± 0.34 × 108 cells/μmole Cl- removed at a rate of 0.062 μM/day and a minimal inhibitory concentration of 0.5 mg/L. Notably, both the tolerance of strain CG1 to triclosan and the rate of triclosan dechlorination increased when CG1 was cultured in the presence of both triclosan and tetrachloroethene. Taken together, our results suggest that anaerobic degradation of organohalide antimicrobials might be more prevalent in mainstream WWTPs than previously speculated, though the low growth yields that are supported by triclosan dechlorination seem to indicate that other organohalide substrates could be necessary to sustain OHRB populations in these systems.
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Affiliation(s)
- Siyan Zhao
- Department of Civil and Environmental Engineering, National University of Singapore, 117576, Singapore
| | - Matthew J Rogers
- Department of Civil and Environmental Engineering, National University of Singapore, 117576, Singapore
| | - Jianzhong He
- Department of Civil and Environmental Engineering, National University of Singapore, 117576, Singapore.
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Preparation and characterization of site-specific dechlorinating microbial inocula capable of complete dechlorination enriched in anaerobic microcosms amended with clay mineral. World J Microbiol Biotechnol 2020; 36:29. [PMID: 32016527 PMCID: PMC6997268 DOI: 10.1007/s11274-020-2806-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Accepted: 01/22/2020] [Indexed: 11/21/2022]
Abstract
Abstract Short-chain halogenated aliphatic hydrocarbons (e.g. perchloroethene, trichloroethene) are among the most toxic environmental pollutants. Perchloroethene and trichloroethene can be dechlorinated to non-toxic ethene through reductive dechlorination by Dehalococcoides sp. Bioaugmentation, applying cultures containing organohalide-respiring microorganisms, is a possible technique to remediate sites contaminated with chlorinated ethenes. Application of site specific inocula is an efficient alternative solution. Our aim was to develop site specific dechlorinating microbial inocula by enriching microbial consortia from groundwater contaminated with trichloroethene using microcosm experiments containing clay mineral as solid phase. Our main goal was to develop fast and reliable method to produce large amount (100 L) of bioactive agent with anaerobic fermentation technology. Polyphasic approach has been applied to monitor the effectiveness of dechlorination during the transfer process from bench-scale (500 mL) to industrial-scale (100 L). Gas chromatography measurement and T-RFLP (Terminal Restriction Fragment Length Polymorphism) revealed that the serial subculture of the enrichments shortened the time-course of the complete dechlorination of trichloroethene to ethene and altered the composition of bacterial communities. Complete dechlorination was observed in enrichments with significant abundance of Dehalococcoides sp. cultivated at 8 °C. Consortia incubated in fermenters at 18 °C accelerated the conversion of TCE to ethene by 7–14 days. Members of the enrichments belong to the phyla Bacteroidetes, Chloroflexi, Proteobacteria and Firmicutes. According to the operational taxonomic units, main differences between the composition of the enrichment incubated at 8 °C and 18 °C occurred with relative abundance of acetogenic and fermentative species. In addition to the temperature, the site-specific origin of the microbial communities and the solid phase applied during the fermentation technique contributed to the development of a unique microbial composition. Graphic abstract ![]()
Electronic supplementary material The online version of this article (10.1007/s11274-020-2806-7) contains supplementary material, which is available to authorized users.
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11
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Pilot-Scale Evaluation of a Permeable Reactive Barrier with Compost and Brown Coal to Treat Groundwater Contaminated with Trichloroethylene. WATER 2019. [DOI: 10.3390/w11091922] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study evaluates, under field conditions, the efficiency of a permeable reactive barrier (PRB) with compost and brown coal to remove trichloroethylene (TCE) (109 µg/L) from contaminated groundwater. Three stainless steel boxes (1.2 × 0.5 × 0.5 m) with the brown coal-compost mixture at three different mixing ratios of 1:1, 1:3, and 1:5 (by volume) were installed to simulate the PRB. Groundwater from the TCE-contaminated aquifer was pumped into the system at a flow rate of 3.6 L/h. Residence times in the boxes were of: 25, 20, 10 h, respectively. Effluent samples were analyzed for TCE and its daughter products: dichloroethylene (DCE), vinyl chloride (VC) and ethane. During the 198-day experimental period TCE concentrations in groundwater decreased below ≤1.1 µg/L, i.e., much lower than groundwater and drinking water standards in Poland. After 16 days cis-1,2-DCE was monitored indicating possible reductive dechlorination of TCE. However, complete transformation of TCE into non-toxic byproducts was not evidenced during the time of experiments, indicating that reductive dechlorination slowed down or stopped at DCE, and that the designed residence times were not long enough to allow the complete dechlorination process.
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Mao X, Stenuit B, Tremblay J, Yu K, Tringe SG, Alvarez-Cohen L. Structural dynamics and transcriptomic analysis of Dehalococcoides mccartyi within a TCE-Dechlorinating community in a completely mixed flow reactor. WATER RESEARCH 2019; 158:146-156. [PMID: 31035191 PMCID: PMC7053656 DOI: 10.1016/j.watres.2019.04.038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 04/10/2019] [Accepted: 04/15/2019] [Indexed: 05/13/2023]
Abstract
A trichloroethene (TCE)-dechlorinating community (CANAS) maintained in a completely mixed flow reactor was established from a semi-batch enrichment culture (ANAS) and was monitored for 400 days at a low solids retention time (SRT) under electron acceptor limitation. Around 85% of TCE supplied to CANAS (0.13 mmol d-1) was converted to ethene at a rate of 0.1 mmol d-1, with detection of low production rates of vinyl chloride (6.8 × 10-3 mmol d-1) and cis-dichloroethene (2.3 × 10-3 mmol d-1). Two distinct Dehalococcoides mccartyi strains (ANAS1 and ANAS2) were stably maintained at 6.2 ± 2.8 × 108 cells mL-1 and 5.8 ± 1.2 × 108 cells mL-1, respectively. Electron balance analysis showed 107% electron recovery, in which 6.1% were involved in dechlorination. 16 S rRNA amplicon sequencing revealed a structural regime shift between ANAS and CANAS while maintaining robust TCE dechlorination due to similar relative abundances of D. mccartyi and functional redundancy among each functional guild supporting D. mccartyi activity. D. mccartyi transcriptomic analysis identified the genes encoding for ribosomal RNA and the reductive dehalogenases tceA and vcrA as the most expressed genes in CANAS, while hup and vhu were the most critical hydrogenases utilized by D. mccartyi in the community.
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Affiliation(s)
- Xinwei Mao
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA, 94720-1710, USA
| | - Benoit Stenuit
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA, 94720-1710, USA
| | | | - Ke Yu
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA, 94720-1710, USA
| | - Susannah G Tringe
- DOE Joint Genome Institute, Walnut Creek, CA, USA; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Lisa Alvarez-Cohen
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA, 94720-1710, USA; Earth and Environmental Sciences Area, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
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Delgado AG, Fajardo-Williams D, Bondank E, Esquivel-Elizondo S, Krajmalnik-Brown R. Coupling Bioflocculation of Dehalococcoides mccartyi to High-Rate Reductive Dehalogenation of Chlorinated Ethenes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:11297-11307. [PMID: 28914537 DOI: 10.1021/acs.est.7b03097] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Continuous bioreactors operated at low hydraulic retention times have rarely been explored for reductive dehalogenation of chlorinated ethenes. The inability to consistently develop such bioreactors affects the way growth approaches for Dehalococcoides mccartyi bioaugmentation cultures are envisioned. It also affects interpretation of results from in situ continuous treatment processes. We report bioreactor performance and dehalogenation kinetics of a D. mccartyi-containing consortium in an upflow bioreactor. When fed synthetic groundwater at 11-3.6 h HRT, the upflow bioreactor removed >99.7% of the influent trichloroethene (1.5-2.8 mM) and produced ethene as the main product. A trichloroethene removal rate of 98.51 ± 0.05 me- equiv L-1 d-1 was achieved at 3.6 h HRT. D. mccartyi cell densities were 1013 and 1012 16S rRNA gene copies L-1 in the bioflocs and planktonic culture, respectively. When challenged with a feed of natural groundwater containing various competing electron acceptors and 0.3-0.4 mM trichloroethene, trichloroethene removal was sustained at >99.6%. Electron micrographs revealed that D. mccartyi were abundant within the bioflocs, not only in multispecies structures, but also as self-aggregated microcolonies. This study provides fundamental evidence toward the feasibility of upflow bioreactors containing D. mccartyi as high-density culture production tools or as a high-rate, real-time remediation biotechnology.
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Affiliation(s)
- Anca G Delgado
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University , Tempe, Arizona 85287-5701, United States
- School of Sustainable Engineering and the Built Environment, Arizona State University , Tempe, Arizona 85287-3005, United States
| | - Devyn Fajardo-Williams
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University , Tempe, Arizona 85287-5701, United States
- School of Sustainable Engineering and the Built Environment, Arizona State University , Tempe, Arizona 85287-3005, United States
| | - Emily Bondank
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University , Tempe, Arizona 85287-5701, United States
| | - Sofia Esquivel-Elizondo
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University , Tempe, Arizona 85287-5701, United States
- School of Sustainable Engineering and the Built Environment, Arizona State University , Tempe, Arizona 85287-3005, United States
| | - Rosa Krajmalnik-Brown
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University , Tempe, Arizona 85287-5701, United States
- School of Sustainable Engineering and the Built Environment, Arizona State University , Tempe, Arizona 85287-3005, United States
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14
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Anaerobic Bioreactors for the Treatment of Chlorinated Hydrocarbons. Ind Biotechnol (New Rochelle N Y) 2016. [DOI: 10.1201/b19347-15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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15
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Impact of Ammonium on Syntrophic Organohalide-Respiring and Fermenting Microbial Communities. mSphere 2016; 1:mSphere00053-16. [PMID: 27303735 PMCID: PMC4894693 DOI: 10.1128/msphere.00053-16] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 03/10/2016] [Indexed: 01/27/2023] Open
Abstract
Contamination with ammonium and chlorinated solvents has been reported in numerous subsurface environments, and these chemicals bring significant challenges for in situ bioremediation. Dehalococcoides mccartyi is able to reduce the chlorinated solvent trichloroethene to the nontoxic end product ethene. Fermentative bacteria are of central importance for organohalide respiration and bioremediation to provide D. mccartyi with H2, their electron donor, acetate, their carbon source, and other micronutrients. In this study, we found that high concentrations of ammonium negatively correlated with rates of trichloroethene reductive dehalogenation and fermentation. However, detoxification of trichloroethene to nontoxic ethene occurred even at ammonium concentrations typical of those found in animal waste (up to 2 g liter−1 NH4+-N). To date, hundreds of subsurface environments have been bioremediated through the unique metabolic capability of D. mccartyi. These findings extend our knowledge of D. mccartyi and provide insight for bioremediation of sites contaminated with chlorinated solvents and ammonium. Syntrophic interactions between organohalide-respiring and fermentative microorganisms are critical for effective bioremediation of halogenated compounds. This work investigated the effect of ammonium concentration (up to 4 g liter−1 NH4+-N) on trichloroethene-reducing Dehalococcoides mccartyi and Geobacteraceae in microbial communities fed lactate and methanol. We found that production of ethene by D. mccartyi occurred in mineral medium containing ≤2 g liter−1 NH4+-N and in landfill leachate. For the partial reduction of trichloroethene (TCE) to cis-dichloroethene (cis-DCE) at ≥1 g liter−1 NH4+-N, organohalide-respiring dynamics shifted from D. mccartyi and Geobacteraceae to mainly D. mccartyi. An increasing concentration of ammonium was coupled to lower metabolic rates, longer lag times, and lower gene abundances for all microbial processes studied. The methanol fermentation pathway to acetate and H2 was conserved, regardless of the ammonium concentration provided. However, lactate fermentation shifted from propionic to acetogenic at concentrations of ≥2 g liter−1 NH4+-N. Our study findings strongly support a tolerance of D. mccartyi to high ammonium concentrations, highlighting the feasibility of organohalide respiration in ammonium-contaminated subsurface environments. IMPORTANCE Contamination with ammonium and chlorinated solvents has been reported in numerous subsurface environments, and these chemicals bring significant challenges for in situ bioremediation. Dehalococcoides mccartyi is able to reduce the chlorinated solvent trichloroethene to the nontoxic end product ethene. Fermentative bacteria are of central importance for organohalide respiration and bioremediation to provide D. mccartyi with H2, their electron donor, acetate, their carbon source, and other micronutrients. In this study, we found that high concentrations of ammonium negatively correlated with rates of trichloroethene reductive dehalogenation and fermentation. However, detoxification of trichloroethene to nontoxic ethene occurred even at ammonium concentrations typical of those found in animal waste (up to 2 g liter−1 NH4+-N). To date, hundreds of subsurface environments have been bioremediated through the unique metabolic capability of D. mccartyi. These findings extend our knowledge of D. mccartyi and provide insight for bioremediation of sites contaminated with chlorinated solvents and ammonium.
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16
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Jugder BE, Ertan H, Bohl S, Lee M, Marquis CP, Manefield M. Organohalide Respiring Bacteria and Reductive Dehalogenases: Key Tools in Organohalide Bioremediation. Front Microbiol 2016; 7:249. [PMID: 26973626 PMCID: PMC4771760 DOI: 10.3389/fmicb.2016.00249] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 02/15/2016] [Indexed: 01/31/2023] Open
Abstract
Organohalides are recalcitrant pollutants that have been responsible for substantial contamination of soils and groundwater. Organohalide-respiring bacteria (ORB) provide a potential solution to remediate contaminated sites, through their ability to use organohalides as terminal electron acceptors to yield energy for growth (i.e., organohalide respiration). Ideally, this process results in non- or lesser-halogenated compounds that are mostly less toxic to the environment or more easily degraded. At the heart of these processes are reductive dehalogenases (RDases), which are membrane bound enzymes coupled with other components that facilitate dehalogenation of organohalides to generate cellular energy. This review focuses on RDases, concentrating on those which have been purified (partially or wholly) and functionally characterized. Further, the paper reviews the major bacteria involved in organohalide breakdown and the evidence for microbial evolution of RDases. Finally, the capacity for using ORB in a bioremediation and bioaugmentation capacity are discussed.
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Affiliation(s)
- Bat-Erdene Jugder
- School of Biotechnology and Biomolecular Sciences, University of New South Wales Sydney, NSW, Australia
| | - Haluk Ertan
- School of Biotechnology and Biomolecular Sciences, University of New South WalesSydney, NSW, Australia; Department of Molecular Biology and Genetics, Istanbul UniversityIstanbul, Turkey
| | - Susanne Bohl
- School of Biotechnology and Biomolecular Sciences, University of New South WalesSydney, NSW, Australia; Department of Biotechnology, Mannheim University of Applied SciencesMannheim, Germany
| | - Matthew Lee
- School of Biotechnology and Biomolecular Sciences, University of New South Wales Sydney, NSW, Australia
| | - Christopher P Marquis
- School of Biotechnology and Biomolecular Sciences, University of New South Wales Sydney, NSW, Australia
| | - Michael Manefield
- School of Biotechnology and Biomolecular Sciences, University of New South Wales Sydney, NSW, Australia
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Mirza BS, Sorensen DL, Dupont RR, McLean JE. Dehalococcoides abundance and alternate electron acceptor effects on large, flow-through trichloroethene dechlorinating columns. Appl Microbiol Biotechnol 2015; 100:2367-79. [PMID: 26536878 DOI: 10.1007/s00253-015-7112-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 10/18/2015] [Accepted: 10/20/2015] [Indexed: 11/25/2022]
Abstract
Trichloroethene (TCE) in groundwater is a major health concern and biostimulation/bioaugmentation-based strategies have been evaluated to achieve complete reductive dechlorination with varying success. Different carbon sources were hypothesized to stimulate different extents of TCE reductive dechlorination. Ecological conditions that developed different dechlorination stages were investigated by quantitating Dehalococcoides 16S rRNA (Dhc) and reductive dehalogenase gene abundance, and by describing biogeochemical properties of laboratory columns in response to this biostimulation. Eight large columns (183 cm × 15.2 cm), packed with aquifer material from Hill AFB, Utah, that were continuously fed TCE for 7.5 years. Duplicate columns were biostimulated with whey or one of two different Newman Zone® emulsified oil formulations containing either nonionic surfactant (EOLN) or standard surfactant (EOL). Two columns were non-stimulated controls. Complete (whey amended), partial (EOLN amended), limited (EOL), and non-TCE dehalogenating systems (controls) developed over the course of the study. Bioaugmentation of half of the columns with Bachman Road culture 3 years prior to dismantling did not influence the extent of TCE dehalogenation. Multivariate analysis clustered samples by biostimulation treatments and extent of TCE dehalogenation. Dhc, tceA, and bvcA gene concentrations did not show a consistent relationship with TCE dehalogenation but the vcrA gene was more abundant in completely dehalogenating, whey-treated columns. The whey columns developed strongly reducing conditions producing Fe(II), sulfide, and methane. Biostimulation with different carbon and energy sources can support high concentrations of diverse Dhc, but carbon addition has a major influence on biogeochemical processes effecting the extent of TCE dehalogenation.
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Affiliation(s)
- Babur S Mirza
- Utah Water Research Laboratory, Utah State University, Logan, UT, 84322-8200, USA
| | - Darwin L Sorensen
- Utah Water Research Laboratory, Utah State University, Logan, UT, 84322-8200, USA
| | - R Ryan Dupont
- Utah Water Research Laboratory, Utah State University, Logan, UT, 84322-8200, USA.,Department of Civil and Environmental Engineering, Utah State University, Logan, UT, 84322-8200, USA
| | - Joan E McLean
- Utah Water Research Laboratory, Utah State University, Logan, UT, 84322-8200, USA. .,Department of Civil and Environmental Engineering, Utah State University, Logan, UT, 84322-8200, USA.
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18
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Li T, Wang J, Wei X, Zhao HY, Zhao ZX, Liu HB. Identification and characterization of a Bacillus methylotrophicus strain with high flocculating activity. RSC Adv 2015. [DOI: 10.1039/c5ra15766h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A novel bioflocculant-producing strain C412 was derived from Bacillus methylotrophicus. The bioflocculant is pH tolerant and thermostable; charge neutralization and bridging are the main flocculation mechanism.
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Affiliation(s)
- Tan Li
- School of Chemistry & Chemical Engineering
- Guangxi University
- Nanning
- China
| | - Jing Wang
- School of Chemistry & Chemical Engineering
- Guangxi University
- Nanning
- China
| | - Xiaoling Wei
- School of Chemistry & Chemical Engineering
- Guangxi University
- Nanning
- China
| | - Hong-Yi Zhao
- School of Chemistry & Chemical Engineering
- Guangxi University
- Nanning
- China
| | - Zhong-Xing Zhao
- School of Chemistry & Chemical Engineering
- Guangxi University
- Nanning
- China
| | - Hai-Bo Liu
- School of Chemistry & Chemical Engineering
- Guangxi University
- Nanning
- China
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Selective enrichment yields robust ethene-producing dechlorinating cultures from microcosms stalled at cis-dichloroethene. PLoS One 2014; 9:e100654. [PMID: 24950250 PMCID: PMC4065118 DOI: 10.1371/journal.pone.0100654] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 05/27/2014] [Indexed: 11/19/2022] Open
Abstract
Dehalococcoides mccartyi strains are of particular importance for bioremediation due to their unique capability of transforming perchloroethene (PCE) and trichloroethene (TCE) to non-toxic ethene, through the intermediates cis-dichloroethene (cis-DCE) and vinyl chloride (VC). Despite the widespread environmental distribution of Dehalococcoides, biostimulation sometimes fails to promote dechlorination beyond cis-DCE. In our study, microcosms established with garden soil and mangrove sediment also stalled at cis-DCE, albeit Dehalococcoides mccartyi containing the reductive dehalogenase genes tceA, vcrA and bvcA were detected in the soil/sediment inocula. Reductive dechlorination was not promoted beyond cis-DCE, even after multiple biostimulation events with fermentable substrates and a lengthy incubation. However, transfers from microcosms stalled at cis-DCE yielded dechlorination to ethene with subsequent enrichment cultures containing up to 109Dehalococcoides mccartyi cells mL−1. Proteobacterial classes which dominated the soil/sediment communities became undetectable in the enrichments, and methanogenic activity drastically decreased after the transfers. We hypothesized that biostimulation of Dehalococcoides in the cis-DCE-stalled microcosms was impeded by other microbes present at higher abundances than Dehalococcoides and utilizing terminal electron acceptors from the soil/sediment, hence, outcompeting Dehalococcoides for H2. In support of this hypothesis, we show that garden soil and mangrove sediment microcosms bioaugmented with their respective cultures containing Dehalococcoides in high abundance were able to compete for H2 for reductive dechlorination from one biostimulation event and produced ethene with no obvious stall. Overall, our results provide an alternate explanation to consolidate conflicting observations on the ubiquity of Dehalococcoides mccartyi and occasional stalling of dechlorination at cis-DCE; thus, bringing a new perspective to better assess biological potential of different environments and to understand microbial interactions governing bioremediation.
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Krzmarzick MJ, Novak PJ. Removal of chlorinated organic compounds during wastewater treatment: achievements and limits. Appl Microbiol Biotechnol 2014; 98:6233-42. [DOI: 10.1007/s00253-014-5800-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 04/25/2014] [Accepted: 04/28/2014] [Indexed: 11/29/2022]
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