1
|
Asai M, Morita Y, Meng L, Miyazaki H, Yoshida N. Dehalococcoides mccartyi strain NIT01 grows more stably in vessels made of pure titanium rather than the stainless alloy SUS304. ENVIRONMENTAL MICROBIOLOGY REPORTS 2023; 15:557-567. [PMID: 37594161 PMCID: PMC10667658 DOI: 10.1111/1758-2229.13192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 07/28/2023] [Indexed: 08/19/2023]
Abstract
Advances in many isolation studies have revealed that pure Dehalococcoides grow stably, although the large-scale pure cultivation of Dehalococcoides has yet to be established. In this study, 7 L-culturing of Dehalococcoides mccartyi strain NIT01 was first performed using vessels made of glass and stainless alloy SUS304. All batches cultured in the glass vessel successfully dechlorinated >95% of 1 mM trichloroethene (TCE) to ethene (ETH), whereas only 5 out of 13 batches cultured in the SUS304 vessel did the same. The difference in dechlorination efficiency suggested the possible inhibition of dechlorination by SUS304. Also, the strain NIT01 showed long delays in dechlorination with pieces of SUS316, steel, and a repeatedly used SUS304, but not with titanium. The repeatedly used SUS304 cracked and increased the Fe2+ concentration to ≥76 μM. Dechlorination by this strain was also inhibited with ≥1000 μM Fe2+ and ≥23 μM Cr3+ but not with ≤100 μM Ni2+ , suggesting that Cr3+ eluted from solid stainless alloys inhibited the dechlorination. Culturing in a titanium vessel instead of a stainless alloy showed the complete dechlorination of 1 mM TCE within 12-28 days with a growth yield of 2.7 × 107 cells/μmol-released Cl- , even after repeating use of the vessels six times.
Collapse
Affiliation(s)
- Masaki Asai
- Department of Civil EngineeringNagoya Institute of TechnologyNagoyaJapan
| | - Yuki Morita
- Department of Civil EngineeringNagoya Institute of TechnologyNagoyaJapan
| | - Lingyu Meng
- Department of Civil EngineeringNagoya Institute of TechnologyNagoyaJapan
| | - Hidetoshi Miyazaki
- Department of Physical Science and EngineeringNagoya Institute of TechnologyNagoyaJapan
| | - Naoko Yoshida
- Department of Civil EngineeringNagoya Institute of TechnologyNagoyaJapan
| |
Collapse
|
2
|
Wu R, Shen R, Liang Z, Zheng S, Yang Y, Lu Q, Adrian L, Wang S. Improve Niche Colonization and Microbial Interactions for Organohalide-Respiring-Bacteria-Mediated Remediation of Chloroethene-Contaminated Sites. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:17338-17352. [PMID: 37902991 DOI: 10.1021/acs.est.3c05932] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/01/2023]
Abstract
Organohalide-respiring bacteria (OHRB)-mediated reductive dehalogenation is promising in in situ bioremediation of chloroethene-contaminated sites. The bioremediation efficiency of this approach is largely determined by the successful colonization of fastidious OHRB, which is highly dependent on the presence of proper growth niches and microbial interactions. In this study, based on two ecological principles (i.e., Priority Effects and Coexistence Theory), three strategies were developed to enhance niche colonization of OHRB, which were tested both in laboratory experiments and field applications: (i) preinoculation of a niche-preparing culture (NPC, being mainly constituted of fermenting bacteria and methanogens); (ii) staggered fermentation; and (iii) increased inoculation of CE40 (a Dehalococcoides-containing tetrachloroethene-to-ethene dechlorinating enrichment culture). Batch experimental results show significantly higher dechlorination efficiencies, as well as lower concentrations of volatile fatty acids (VFAs) and methane, in experimental sets with staggered fermentation and niche-preconditioning with NPC for 4 days (CE40_NPC-4) relative to control sets. Accordingly, a comparatively higher abundance of Dehalococcoides as major OHRB, together with a lower abundance of fermenting bacteria and methanogens, was observed in CE40_NPC-4 with staggered fermentation, which indicated the balanced syntrophic and competitive interactions between OHRB and other populations for the efficient dechlorination. Further experiments with microbial source tracking analyses suggested enhanced colonization of OHRB by increasing the inoculation ratio of CE40. The optimized conditions for enhanced colonization of OHRB were successfully employed for field bioremediation of trichloroethene (TCE, 0.3-1.4 mM)- and vinyl chloride (VC, ∼0.04 mM)-contaminated sites, resulting in 96.6% TCE and 99.7% VC dechlorination to ethene within 5 and 3 months, respectively. This study provides ecological principles-guided strategies for efficient bioremediation of chloroethene-contaminated sites, which may be also employed for removal of other emerging organohalide pollutants.
Collapse
Affiliation(s)
- Rifeng Wu
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou 510006, China
| | - Rui Shen
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou 510006, China
| | - Zhiwei Liang
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou 510006, China
| | - Shengzhi Zheng
- China State Science Dingshi Environmental Engineering Co., Ltd., Beijing 100102, China
| | - Yong Yang
- China State Science Dingshi Environmental Engineering Co., Ltd., Beijing 100102, China
| | - Qihong Lu
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou 510006, China
| | - Lorenz Adrian
- Environmental Biotechnology, Helmholtz Centre for Environmental Research-UFZ, Permoserstraße 15, 04318 Leipzig, Germany
- Chair of Geobiotechnology, Technische Universität Berlin, Ackerstraße 76, 13355 Berlin, Germany
| | - Shanquan Wang
- School of Environmental Science and Engineering, Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou 510006, China
| |
Collapse
|
3
|
Xu G, Zhao X, Zhao S, Rogers MJ, He J. Salinity determines performance, functional populations, and microbial ecology in consortia attenuating organohalide pollutants. THE ISME JOURNAL 2023; 17:660-670. [PMID: 36765150 PMCID: PMC10119321 DOI: 10.1038/s41396-023-01377-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 01/25/2023] [Accepted: 01/31/2023] [Indexed: 02/12/2023]
Abstract
Organohalide pollutants are prevalent in coastal regions due to extensive intervention by anthropogenic activities, threatening public health and ecosystems. Gradients in salinity are a natural feature of coasts, but their impacts on the environmental fate of organohalides and the underlying microbial communities remain poorly understood. Here we report the effects of salinity on microbial reductive dechlorination of tetrachloroethene (PCE) and polychlorinated biphenyls (PCBs) in consortia derived from distinct environments (freshwater and marine sediments). Marine-derived microcosms exhibited higher halotolerance during PCE and PCB dechlorination, and a halotolerant dechlorinating culture was enriched from these microcosms. The organohalide-respiring bacteria (OHRB) responsible for PCE and PCB dechlorination in marine microcosms shifted from Dehalococcoides to Dehalobium when salinity increased. Broadly, lower microbial diversity, simpler co-occurrence networks, and more deterministic microbial community assemblages were observed under higher salinity. Separately, we observed that inhibition of dechlorination by high salinity could be attributed to suppressed viability of Dehalococcoides rather than reduced provision of substrates by syntrophic microorganisms. Additionally, the high activity of PCE dechlorinating reductive dehalogenases (RDases) in in vitro tests under high salinity suggests that high salinity likely disrupted cellular components other than RDases in Dehalococcoides. Genomic analyses indicated that the capability of Dehalobium to perform dehalogenation under high salinity was likely owing to the presence of genes associated with halotolerance in its genomes. Collectively, these mechanistic and ecological insights contribute to understanding the fate and bioremediation of organohalide pollutants in environments with changing salinity.
Collapse
Affiliation(s)
- Guofang Xu
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore, 117576, Singapore
- NUS Graduate School - Integrative Sciences and Engineering Programme (ISEP), National University of Singapore, Singapore, 119077, Singapore
| | - Xuejie Zhao
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore, 117576, Singapore
| | - Siyan Zhao
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore, 117576, Singapore
| | - Matthew J Rogers
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore, 117576, Singapore
| | - Jianzhong He
- Department of Civil and Environmental Engineering, National University of Singapore, Singapore, 117576, Singapore.
- NUS Graduate School - Integrative Sciences and Engineering Programme (ISEP), National University of Singapore, Singapore, 119077, Singapore.
| |
Collapse
|
4
|
Hwangbo M, Shao Y, Hatzinger PB, Chu KH. Acidophilic methanotrophs: Occurrence, diversity, and possible bioremediation applications. ENVIRONMENTAL MICROBIOLOGY REPORTS 2023. [PMID: 37041665 DOI: 10.1111/1758-2229.13156] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 03/23/2023] [Indexed: 06/19/2023]
Abstract
Methanotrophs have been identified and isolated from acidic environments such as wetlands, acidic soils, peat bogs, and groundwater aquifers. Due to their methane (CH4 ) utilization as a carbon and energy source, acidophilic methanotrophs are important in controlling the release of atmospheric CH4 , an important greenhouse gas, from acidic wetlands and other environments. Methanotrophs have also played an important role in the biodegradation and bioremediation of a variety of pollutants including chlorinated volatile organic compounds (CVOCs) using CH4 monooxygenases via a process known as cometabolism. Under neutral pH conditions, anaerobic bioremediation via carbon source addition is a commonly used and highly effective approach to treat CVOCs in groundwater. However, complete dechlorination of CVOCs is typically inhibited at low pH. Acidophilic methanotrophs have recently been observed to degrade a range of CVOCs at pH < 5.5, suggesting that cometabolic treatment may be an option for CVOCs and other contaminants in acidic aquifers. This paper provides an overview of the occurrence, diversity, and physiological activities of methanotrophs in acidic environments and highlights the potential application of these organisms for enhancing contaminant biodegradation and bioremediation.
Collapse
Affiliation(s)
- Myung Hwangbo
- Zachry Department of Civil and Environmental Engineering, Texas A&M University, College Station, Texas, USA
| | - Yiru Shao
- Zachry Department of Civil and Environmental Engineering, Texas A&M University, College Station, Texas, USA
| | - Paul B Hatzinger
- Aptim Federal Services, LLC, 17 Princess Road, Lawrenceville, New Jersey, USA
| | - Kung-Hui Chu
- Zachry Department of Civil and Environmental Engineering, Texas A&M University, College Station, Texas, USA
| |
Collapse
|
5
|
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: 6] [Impact Index Per Article: 6.0] [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.
Collapse
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
| |
Collapse
|
6
|
Hudari MSB, Richnow H, Vogt C, Nijenhuis I. Mini-review: effect of temperature on microbial reductive dehalogenation of chlorinated ethenes: a review. FEMS Microbiol Ecol 2022; 98:6638985. [PMID: 35810002 DOI: 10.1093/femsec/fiac081] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 06/30/2022] [Accepted: 07/07/2022] [Indexed: 11/13/2022] Open
Abstract
Temperature is a key factor affecting microbial activity and ecology. An increase in temperature generally increases rates of microbial processes up to a certain threshold, above which rates decline rapidly. In the subsurface, temperature of groundwater is usually stable and related to the annual average temperature at the surface. However, anthropogenic activities related to the use of the subsurface, e.g. for thermal heat management, foremost heat storage, will affect the temperature of groundwater locally. This mini-review intends to summarize the current knowledge on reductive dehalogenation activities of the chlorinated ethenes, common urban groundwater contaminants, at different temperatures. This includes an overview of activity and dehalogenation extent at different temperatures in laboratory isolates and enrichment cultures, the effect of shifts in temperature in micro- and mesocosm studies as well as observed biotransformation at different natural and induced temperatures at contaminated field sites. Furthermore, we address indirect effects on biotransformation, e.g. changes in fermentation, methanogenesis and sulfate reduction as competing or synergetic microbial processes. Finally, we address the current gaps in knowledge regarding bioremediation of chlorinated ethenes, microbial community shifts and bottlenecks for active combination with thermal energy storage, and necessities for bioaugmentation and/or natural re-populations after exposure to high temperature.
Collapse
Affiliation(s)
- Mohammad Sufian Bin Hudari
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Hans Richnow
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Permoserstrasse 15, 04318 Leipzig, Germany
| | - Carsten Vogt
- 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
| |
Collapse
|
7
|
Xu G, Zhang N, Zhao X, Chen C, Zhang C, He J. Offshore Marine Sediment Microbiota Respire Structurally Distinct Organohalide Pollutants. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:3065-3075. [PMID: 35187933 DOI: 10.1021/acs.est.1c06680] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Marine sediments are a major sink of organohalide pollutants, but the potential for offshore marine microbiota to transform these pollutants remains underexplored. Here, we report dehalogenation of diverse organohalide pollutants by offshore marine microbiota. Dechlorination of polychlorinated biphenyls (PCBs) was observed in four marine sediment microcosms, which was positively correlated with in situ PCB contamination. Three distinct enrichment cultures were enriched from these PCB-dechlorinating microcosms using tetrachloroethene (PCE) as the sole organohalide. All enrichment cultures also dehalogenated polybrominated diphenyl ethers (PBDEs), tetrabromobisphenol A (TBBPA), and 2,4,6-trichlorophenol (2,4,6-TCP). Particularly, two enrichments completely debrominated penta-BDEs, the first observation of complete debromination of penta-BDEs in marine cultures. Multiple Dehalococcoides and uncultivated Dehalococcoidia were identified in the initial sediment microcosms, but only Dehalococcoides was dominant in all enrichments. Transcription of a gene encoding a PcbA5-like reductive dehalogenase (RDase) was observed during dehalogenation of different organohalides in each enrichment culture. When induced by a single organohalide substrate, the PcbA5-like RDase dehalogenated all tested organohalides (PCE, PCBs, PBDEs, TBBPA, and 2,4,6-TCP) in in vitro tests, suggesting its involvement in dehalogenation of structurally distinct organohalides. Our results demonstrate the versatile dehalogenation capacity of marine Dehalococcoidia and contribute to a better understanding of the fate of these pollutants in marine systems.
Collapse
Affiliation(s)
- Guofang Xu
- Department of Civil and Environmental Engineering, National University of Singapore, Block E2-02-13, 1 Engineering Drive 3, Singapore 117576, Singapore
- NUS Graduate School─Integrative Sciences and Engineering Programme (ISEP), National University of Singapore, Singapore 119077, Singapore
| | - Ning Zhang
- Department of Civil and Environmental Engineering, National University of Singapore, Block E2-02-13, 1 Engineering Drive 3, Singapore 117576, Singapore
- Institute of Marine Biology and Pharmacology, Ocean College, Zhejiang University, Zhoushan, Zhejiang 316021, China
- College of Chemical Engineering and Pharmacy, Henan University of Science and Technology, Luoyang, Henan 471003, China
| | - Xuejie Zhao
- Department of Civil and Environmental Engineering, National University of Singapore, Block E2-02-13, 1 Engineering Drive 3, Singapore 117576, Singapore
| | - Chen Chen
- Department of Civil and Environmental Engineering, National University of Singapore, Block E2-02-13, 1 Engineering Drive 3, Singapore 117576, Singapore
| | - Chunfang Zhang
- Institute of Marine Biology and Pharmacology, Ocean College, Zhejiang University, Zhoushan, Zhejiang 316021, China
| | - Jianzhong He
- Department of Civil and Environmental Engineering, National University of Singapore, Block E2-02-13, 1 Engineering Drive 3, Singapore 117576, Singapore
| |
Collapse
|
8
|
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: 22] [Impact Index Per Article: 7.3] [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.
Collapse
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
| |
Collapse
|
9
|
Li F, Deng D, Zeng L, Abrams S, Li M. Sequential anaerobic and aerobic bioaugmentation for commingled groundwater contamination of trichloroethene and 1,4-dioxane. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 774:145118. [PMID: 33610989 DOI: 10.1016/j.scitotenv.2021.145118] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 12/04/2020] [Accepted: 01/07/2021] [Indexed: 06/12/2023]
Abstract
Chlorinated solvents, notably trichloroethene (TCE), and the cyclic ether stabilizer, 1,4-dioxane (dioxane), have been frequently detected commingling in contaminated aquifers. Here we developed a sequential anaerobic and aerobic treatment strategy effective to mitigate the co-contamination of TCE and dioxane, particularly when dioxane is present at ppb levels relevant to many impacted sites. After the primary anaerobic treatment by a halorespiring consortium SDC-9, TCE was effectively removed, though lingering less-chlorinated metabolites, vinyl chloride (VC) and cis-dichloroethene (cDCE). Subsequent aerobic bioaugmentation with Azoarcus sp. DD4, a cometabolic dioxane degrader, demonstrated the ability of DD4 to degrade dioxane at an initial concentration of 20 μg/L to below 0.4 μg/L and its dominance (~7%) in microcosms fed with propane. Even better, DD4 can also transform VC and cDCE in tandem, though cDCE and VC at relatively high concentrations (e.g., 1 mg/L) posed inhibition to propane assimilation and cell growth of DD4. Mutagenesis of DD4 revealed group-2 toluene monooxygenase and group-5 propane monooxygenase are responsible for cDCE and VC co-oxidation, respectively. Overall, we demonstrated the feasibility of a treatment train combining reductive dehalogenation and aerobic co-oxidation processes in tandem to not only effectively clean up prevalent co-contamination of TCE and dioxane at trace levels but also mitigate persistent products (e.g., cDCE and VC) when complete reductive dehalogenation of less-chlorinated ethenes occurs slowly in the field.
Collapse
Affiliation(s)
- Fei Li
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ 07102, USA
| | - Daiyong Deng
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ 07102, USA
| | - Lingke Zeng
- Langan Engineering, Parsippany, NJ 07054, USA
| | | | - Mengyan Li
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ 07102, USA.
| |
Collapse
|
10
|
Ebrahimbabaie P, Pichtel J. Biotechnology and nanotechnology for remediation of chlorinated volatile organic compounds: current perspectives. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:7710-7741. [PMID: 33403642 DOI: 10.1007/s11356-020-11598-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Accepted: 11/09/2020] [Indexed: 06/12/2023]
Abstract
Chlorinated volatile organic compounds (CVOCs) are persistent organic pollutants which are harmful to public health and the environment. Many CVOCs occur in substantial quantities in groundwater and soil, even though their use has been more carefully managed and restricted in recent years. This review summarizes recent data on several innovative treatment solutions for CVOC-affected media including bioremediation, phytoremediation, nanoscale zero-valent iron (nZVI)-based reductive dehalogenation, and photooxidation. There is no optimally developed single technology; therefore, the possibility of using combined technologies for CVOC remediation, for example bioremediation integrated with reduction by nZVI, is presented. Some methods are still in the development stage. Advantages and disadvantages of each treatment strategy are provided. It is hoped that this paper can provide a basic framework for selection of successful CVOC remediation strategies.
Collapse
Affiliation(s)
- Parisa Ebrahimbabaie
- Department of Environment, Geology, and Natural Resources, Ball State University, Muncie, IN, 47306, USA
| | - John Pichtel
- Department of Environment, Geology, and Natural Resources, Ball State University, Muncie, IN, 47306, USA.
| |
Collapse
|
11
|
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: 21] [Impact Index Per Article: 5.3] [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-.
Collapse
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
| |
Collapse
|
12
|
Kucharzyk KH, Meisel JE, Kara-Murdoch F, Murdoch RW, Higgins SA, Vainberg S, Bartling CM, Mullins L, Hatzinger PB, Löffler FE. Metagenome-Guided Proteomic Quantification of Reductive Dehalogenases in the Dehalococcoides mccartyi-Containing Consortium SDC-9. J Proteome Res 2020; 19:1812-1823. [PMID: 32135063 DOI: 10.1021/acs.jproteome.0c00072] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
At groundwater sites contaminated with chlorinated ethenes, fermentable substrates are often added to promote reductive dehalogenation by indigenous or augmented microorganisms. Contemporary bioremediation performance monitoring relies on nucleic acid biomarkers of key organohalide-respiring bacteria, such as Dehalococcoides mccartyi (Dhc). Metagenome sequencing of the commercial, Dhc-containing consortium, SDC-9, identified 12 reductive dehalogenase (RDase) genes, including pceA (two copies), vcrA, and tceA, and allowed for specific detection and quantification of RDase peptides using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). Shotgun (i.e., untargeted) proteomics applied to the SDC-9 consortium grown with tetrachloroethene (PCE) and lactate identified 143 RDase peptides, and 36 distinct peptides that covered greater than 99% of the protein-coding sequences of the PceA, TceA, and VcrA RDases. Quantification of RDase peptides using multiple reaction monitoring (MRM) assays with 13C-/15N-labeled peptides determined 1.8 × 103 TceA and 1.2 × 102 VcrA RDase molecules per Dhc cell. The MRM mass spectrometry approach allowed for sensitive detection and accurate quantification of relevant Dhc RDases and has potential utility in bioremediation monitoring regimes.
Collapse
Affiliation(s)
| | - Jayda E Meisel
- Battelle Memorial Institute, 505 King Avenue, Columbus, Ohio 43201, United States
| | - Fadime Kara-Murdoch
- Department of Microbiology, University of Tennessee, 1311 Cumberland Avenue, Knoxville, Tennessee 37996, United States.,Department of Biosystems Engineering and Soil Science University of Tennessee, 2506 E. J. Chapman Drive, Knoxville, Tennessee 37996, United States
| | - Robert W Murdoch
- Center for Environmental Biotechnology, University of Tennessee, 1416 Circle Drive, Knoxville, Tennessee 37996, United States.,Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, United States
| | - Steven A Higgins
- Department of Microbiology, University of Tennessee, 1311 Cumberland Avenue, Knoxville, Tennessee 37996, United States
| | - Simon Vainberg
- APTIM, Biotechnology Development and Applications Group, 17 Princess Road, Lawrenceville, New Jersey 08648, United States
| | - Craig M Bartling
- Battelle Memorial Institute, 505 King Avenue, Columbus, Ohio 43201, United States
| | - Larry Mullins
- Battelle Memorial Institute, 505 King Avenue, Columbus, Ohio 43201, United States
| | - Paul B Hatzinger
- APTIM, Biotechnology Development and Applications Group, 17 Princess Road, Lawrenceville, New Jersey 08648, United States
| | - Frank E Löffler
- Department of Microbiology, University of Tennessee, 1311 Cumberland Avenue, Knoxville, Tennessee 37996, United States.,Center for Environmental Biotechnology, University of Tennessee, 1416 Circle Drive, Knoxville, Tennessee 37996, United States.,Department of Civil and Environmental Engineering, University of Tennessee, 851 Neyland Drive, Knoxville, Tennessee 37996, United States.,Department of Biosystems Engineering and Soil Science University of Tennessee, 2506 E. J. Chapman Drive, Knoxville, Tennessee 37996, United States.,Biosciences Division, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, Tennessee 37831, United States
| |
Collapse
|
13
|
Ramalingam V, Cupples AM. Anaerobic 1,4-dioxane biodegradation and microbial community analysis in microcosms inoculated with soils or sediments and different electron acceptors. Appl Microbiol Biotechnol 2020; 104:4155-4170. [DOI: 10.1007/s00253-020-10512-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 02/17/2020] [Accepted: 02/28/2020] [Indexed: 11/29/2022]
|
14
|
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.
Collapse
|
15
|
Chen WY, Wu JH, Chu SC. Deciphering microbiomes in anaerobic reactors with superior trichloroethylene dechlorination performance at low pH conditions. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 257:113567. [PMID: 31733964 DOI: 10.1016/j.envpol.2019.113567] [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] [Received: 07/11/2019] [Revised: 10/30/2019] [Accepted: 11/02/2019] [Indexed: 06/10/2023]
Abstract
Different pH conditions have been demonstrated to affect the activities of dechlorinating populations participating in the successive dechlorination of trichloroethylene to ethylene. However, the mechanism of the effect of pH conditions on the assembly of dechlorinating populations and their relations to the structure, function, and dynamics of the microbiome are unclear. In this study, we evaluated the effects of pH on microbiomes assembled in anaerobic trichloroethylene-dechlorinating reactors under neutral (pH 7.2), acidic (pH 6.2), and alkaline (pH 8.2) conditions. The results revealed that among the reactors, the acidic reactor had the highest efficiency for dechlorination without accumulation of dechlorinated metabolites, even at high loading rates. The results of high-throughput sequencing of the 16S rRNA gene indicated that the microbiomes in the 3 reactors underwent varied dynamic succession. The acidic reactor harbored a higher degree of complex microbes, dechlorinator diversity, and abundance of the Victoria subgroup of Dehalococcoides (1.2 ± 0.1 × 106 cell/mL), which were approximately 10-102-fold higher than those at neutral and alkaline conditions. The pH settings altered species-species connectivity and complexity of microbial interaction networks, with more commensal interactions in the dechlorinators of the acidic reactor. As predicted, abundances of several functional gene categories were in strong linearity with pH values, and the microbiome possessed significantly more abundant functions in the acidic reactor (P < 0.001), such as potentially stimulating hydrogen production, cobalamin synthesis, cobalt transport, transport and metabolism of amino acids and secondary metabolites, cell motility, and transcription. All results of microbiomic analyses consistently revealed the observed superior dechlorination process and suggested an association of the reductive dechlorination process with the pH-dependent microbiome. The results of this study provide a new insight into the trichloroethylene dechlorination with regards to pH, and they will be useful for improving bioremediation and management of trichloroethylene-contaminated sites.
Collapse
Affiliation(s)
- Wei-Yu Chen
- Department of Environmental Engineering, National Cheng Kung University, Taiwan
| | - Jer-Horng Wu
- Department of Environmental Engineering, National Cheng Kung University, Taiwan.
| | - Shun-Chieh Chu
- Environmental Forensic Department, Sustainable Environment Technology Division, Green Energy and Environment Research Labs (GEL), Industrial Technology Research Institute, Taiwan
| |
Collapse
|
16
|
Reductive/Oxidative Sequential Bioelectrochemical Process for Perchloroethylene Removal. WATER 2019. [DOI: 10.3390/w11122579] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
An innovative bioelectrochemical reductive/oxidative sequential process was developed and tested on a laboratory scale to obtain the complete mineralization of perchloroethylene (PCE) in a synthetic medium. The sequential bioelectrochemical process consisted of two separate tubular bioelectrochemical reactors that adopted a novel reactor configuration, avoiding the use of an ion exchange membrane to separate the anodic and cathodic chamber and reducing the cost of the reactor. In the reductive reactor, a dechlorinating mixed inoculum received reducing power to perform the reductive dechlorination of perchloroethylene (PCE) through a cathode chamber, while the less chlorinated daughter products were removed in the oxidative reactor, which supported an aerobic dechlorinating culture through in situ electrochemical oxygen evolution. Preliminary fluid dynamics and electrochemical tests were performed to characterize both the reductive and oxidative reactors, which were electrically independent of each other, with each having its own counterelectrode. The first continuous-flow potentiostatic run with the reductive reactor (polarized at −450 mV vs SHE) resulted in obtaining 100% ± 1% removal efficiency of the influent PCE, while the oxidative reactor (polarized at +1.4 V vs SHE) oxidized the vinyl chloride and ethylene from the reductive reactor, with removal efficiencies of 100% ± 2% and 92% ± 1%, respectively.
Collapse
|
17
|
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.
Collapse
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.
| |
Collapse
|
18
|
Borden RC, Richardson SD, Bodour AA. Enhanced reductive dechlorination of trichloroethene in an acidic DNAPL impacted aquifer. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 237:617-628. [PMID: 30831431 DOI: 10.1016/j.jenvman.2018.12.093] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 12/18/2018] [Accepted: 12/25/2018] [Indexed: 06/09/2023]
Abstract
A field pilot test was conducted using an emulsified vegetable oil (EVO) and colloidal magnesium hydroxide [Mg(OH)2] formulation to enhance reductive dechlorination of dense non-aqueous phase liquid (DNAPL) trichloroethene (TCE) in an acidic (pH < 4), heterogeneous aquifer. The field test consisted of i) a single well injection test to evaluate Mg(OH)2 distribution and ii) installation of two EVO-Mg(OH)2 permeable reactive barriers (PRBs; PRB-1 & PRB-2) at varying distances downgradient of the DNAPL source area. Distribution of Mg(OH)2 was observed up to 2.3 m away from the injection point within a permeable coarse sand layer; however, Mg(OH)2 transport in the overlying clayey-silty sand was minimal. Downgradient of the PRBs, colloidal Mg(OH)2 increased the pH of the coarse sand to levels appropriate for biological reductive dechlorination (pH >∼5); however, some settling of Mg(OH)2 in the injection wells generated persistent high pH (∼9-10) within the PRBs. A redesigned suspension of colloidal Mg(OH)2 was tested and proved to be more effective at raising aquifer pH without an excessive rise in pH within the PRBs. At PRB-1 (located closest to the DNAPL source area), limited TCE biodegradation was observed due to the influx of high TCE concentrations (up to 400 mg/L) and inhibition of dechlorinating bacteria. At PRB-2 (located 25 m downgradient of the DNAPL source area), TCE concentrations were much lower (13-26 mg/L) and production of cis-1,2-dichloroethene (cDCE) and some vinyl chloride (VC) was observed. Subsequent bioaugmentation with a commercial dechlorinating culture at PRB-2 improved conversion of cDCE to VC and ethene at downgradient monitoring wells over the duration of the study. These results emphasize the importance of PRB location (relative to the DNAPL source), base selection for pH adjustment, source strength, and local heterogeneities for the design and long-term performance of ERD in acidic DNAPL-impacted aquifers.
Collapse
Affiliation(s)
| | | | - Adria A Bodour
- Air Force Civil Engineer Center, San Antonio, TX 78136, United States
| |
Collapse
|
19
|
Shao Y, Hatzinger PB, Streger SH, Rezes RT, Chu KH. Evaluation of methanotrophic bacterial communities capable of biodegrading trichloroethene (TCE) in acidic aquifers. Biodegradation 2019; 30:173-190. [DOI: 10.1007/s10532-019-09875-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 04/04/2019] [Indexed: 10/27/2022]
|
20
|
Niño de Guzmán GT, Hapeman CJ, Millner PD, Torrents A, Jackson D, Kjellerup BV. Presence of organohalide-respiring bacteria in and around a permeable reactive barrier at a trichloroethylene-contaminated Superfund site. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 243:766-776. [PMID: 30228068 DOI: 10.1016/j.envpol.2018.08.095] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 08/29/2018] [Accepted: 08/29/2018] [Indexed: 06/08/2023]
Abstract
Trichloroethylene (TCE) is one of the most common groundwater contaminants in the United States; however clean-up efforts are a challenge due to its physical and chemical properties. TCE and several of its degradation products were detected in the groundwater of the Beaver Dam Road Landfill site (Beltsville, MD) at concentrations above accepted maximum contaminant levels. A permeable reactive barrier (i.e., biowall) was installed to remediate the groundwater. Microbial infiltration and colonization of the biowall with native site bacteria was expected to occur. An array of molecular biological tools was applied to survey the microbial community for presence of organohalide-respiring microorganisms at the site. Microorganisms belonging to methanogens, acetogens, sulfate-reducing bacteria, and chlorinated aliphatic hydrocarbon-metabolizing bacteria were identified, thus making way for the application of the microbial populations in the biowall bioaugmentation efforts. In concomitant laboratory studies, molecular approaches were used to monitor continuously-fed column reactors containing saturated biowall material spiked with a commercially-available, Dehalococcoides-containing culture (SDC-9), with or without zero-valent iron (ZVI) shavings. The column without ZVI had the highest abundance of Dehalococcoides spp. (2.7 × 106 cells g-1 material, S.D. = 3.8 × 105 cells g-1 material), while the addition of ZVI did not affect the overall population. Although the addition of ZVI and biostimulation did change ratios of the Dehalococcoides strains, the results suggests that if ZVI would be applied as a biowall material amendment, biostimulation would not be required to maintain a Dehalococcoides population. These experimental results will be utilized in future remediation and/or biowall expansion plans to utilize the natural resources most effectively at the biowall site.
Collapse
Affiliation(s)
| | - Cathleen J Hapeman
- US Department of Agriculture, Agricultural Research Service, Beltsville, MD, USA
| | - Patricia D Millner
- US Department of Agriculture, Agricultural Research Service, Beltsville, MD, USA
| | - Alba Torrents
- Department of Civil and Environmental Engineering, University of Maryland, College Park, MD, USA
| | - Dana Jackson
- US Department of Agriculture, Agricultural Research Service, Beltsville, MD, USA
| | - Birthe V Kjellerup
- Department of Civil and Environmental Engineering, University of Maryland, College Park, MD, USA.
| |
Collapse
|
21
|
Collins FA, Fisher K, Payne KAP, Gaytan Mondragon S, Rigby SEJ, Leys D. NADPH-Driven Organohalide Reduction by a Nonrespiratory Reductive Dehalogenase. Biochemistry 2018; 57:3493-3502. [PMID: 29630828 DOI: 10.1021/acs.biochem.8b00255] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Reductive dehalogenases are corrinoid and iron-sulfur cluster-dependent enzymes that mostly act as the terminal oxidoreductases in the bacterial organohalide respiration process. This process often leads to detoxification of recalcitrant organohalide pollutants. While low cell yields and oxygen sensitivity hamper the study of many reductive dehalogenases, this is not the case for the nonrespiratory reductive dehalogenase NpRdhA from Nitratireductor pacificus. We here report in vitro and in vivo reconstitution of an NADPH-dependent reducing system for NpRdhA. Surprisingly, NpRdhA mediated organohalide reduction could not be supported using N. pacificus ferredoxin-NAD(P)H oxidoreductase and associated ferredoxins. Instead, we found a nonphysiological system comprised of the Escherichia coli flavodoxin reductase (EcFldr) in combination with spinach ferredoxin (SpFd) was able to support NADPH-dependent organohalide reduction by NpRdhA. Using this system, organohalide reduction can be performed under both anaerobic and aerobic conditions, with 1.1 ± 0.1 and 3.5 ± 0.3 equiv of NADPH consumed per product produced, respectively. No significant enzyme inactivation under aerobic conditions was observed, suggesting a Co(I) species is unlikely to be present under steady state conditions. Furthermore, reduction of the Co(II) resting state was not observed in the absence of substrate. Only the coexpression of EcFldr, SpFd, and NpRdhA in Bacillus megaterium conferred the latter with the ability to reduce brominated NpRdhA substrates in vivo, in agreement with our in vitro observations. Our work provides new insights into biological reductive dehalogenase reduction and establishes a blueprint for the minimal functional organohalide reduction module required for bioremediation in situ.
Collapse
Affiliation(s)
- Fraser A Collins
- Manchester Institute of Biotechnology , University of Manchester , 131 Princess Street , Manchester M1 7DN , U.K
| | - Karl Fisher
- Manchester Institute of Biotechnology , University of Manchester , 131 Princess Street , Manchester M1 7DN , U.K
| | - Karl A P Payne
- Manchester Institute of Biotechnology , University of Manchester , 131 Princess Street , Manchester M1 7DN , U.K
| | - Samantha Gaytan Mondragon
- Manchester Institute of Biotechnology , University of Manchester , 131 Princess Street , Manchester M1 7DN , U.K
| | - Stephen E J Rigby
- Manchester Institute of Biotechnology , University of Manchester , 131 Princess Street , Manchester M1 7DN , U.K
| | - David Leys
- Manchester Institute of Biotechnology , University of Manchester , 131 Princess Street , Manchester M1 7DN , U.K
| |
Collapse
|
22
|
Koster van Groos PG, Hatzinger PB, Streger SH, Vainberg S, Philp RP, Kuder T. Carbon Isotope Fractionation of 1,2-Dibromoethane by Biological and Abiotic Processes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:3440-3448. [PMID: 29493235 DOI: 10.1021/acs.est.7b05224] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Affiliation(s)
- Paul G. Koster van Groos
- Biotechnology Development and Applications Group, APTIM, 17 Princess Road, Lawrenceville, New Jersey 08648, United States
| | - Paul B. Hatzinger
- Biotechnology Development and Applications Group, APTIM, 17 Princess Road, Lawrenceville, New Jersey 08648, United States
| | - Sheryl H. Streger
- Biotechnology Development and Applications Group, APTIM, 17 Princess Road, Lawrenceville, New Jersey 08648, United States
| | - Simon Vainberg
- Biotechnology Development and Applications Group, APTIM, 17 Princess Road, Lawrenceville, New Jersey 08648, United States
| | - R. Paul Philp
- School of Geology and Geophysics, University of Oklahoma, 100 E. Boyd Street SEC 710, Norman, Oklahoma 73019, United States
| | - Tomasz Kuder
- School of Geology and Geophysics, University of Oklahoma, 100 E. Boyd Street SEC 710, Norman, Oklahoma 73019, United States
| |
Collapse
|
23
|
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.
Collapse
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.
| |
Collapse
|
24
|
Yang Y, Cápiro NL, Yan J, Marcet TF, Pennell KD, Löffler FE. Resilience and recovery of Dehalococcoides mccartyi following low pH exposure. FEMS Microbiol Ecol 2017; 93:4411799. [DOI: 10.1093/femsec/fix130] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 10/05/2017] [Indexed: 11/12/2022] Open
Affiliation(s)
- Yi Yang
- Department of Civil and Environmental Engineering, University of Tennessee, 325 John D. Tickle Bldg, 851 Neyland Drive, Knoxville, TN 37996, USA
- Center for Environmental Biotechnology, University of Tennessee, 676 Dabney Hall, 1416 Circle Drive, Knoxville, TN 37996, USA
- Joint Institute for Biological Sciences (JIBS), Oak Ridge National Laboratory, Bldg 1520, Bethel Valley Road, Oak Ridge, TN 37831, USA
| | - Natalie L. Cápiro
- Department of Civil and Environmental Engineering, 200 College Avenue, Tufts University, Medford, MA 02155, USA
| | - Jun Yan
- Center for Environmental Biotechnology, University of Tennessee, 676 Dabney Hall, 1416 Circle Drive, Knoxville, TN 37996, USA
- Joint Institute for Biological Sciences (JIBS), Oak Ridge National Laboratory, Bldg 1520, Bethel Valley Road, Oak Ridge, TN 37831, USA
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning 110016, China
- Department of Microbiology, University of Tennessee, M409 Walters Life Science Bldg, Knoxville, TN 37996, USA
| | - Tyler F. Marcet
- Department of Civil and Environmental Engineering, 200 College Avenue, Tufts University, Medford, MA 02155, USA
| | - Kurt D. Pennell
- Department of Civil and Environmental Engineering, 200 College Avenue, Tufts University, Medford, MA 02155, USA
| | - Frank E. Löffler
- Department of Civil and Environmental Engineering, University of Tennessee, 325 John D. Tickle Bldg, 851 Neyland Drive, Knoxville, TN 37996, USA
- Center for Environmental Biotechnology, University of Tennessee, 676 Dabney Hall, 1416 Circle Drive, Knoxville, TN 37996, USA
- Joint Institute for Biological Sciences (JIBS), Oak Ridge National Laboratory, Bldg 1520, Bethel Valley Road, Oak Ridge, TN 37831, USA
- Department of Microbiology, University of Tennessee, M409 Walters Life Science Bldg, Knoxville, TN 37996, USA
- Department of Biosystems Engineering and Soil Science, University of Tennessee, 2506 E.J. Chapman Dr., Knoxville, TN 37996, USA
| |
Collapse
|
25
|
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.
Collapse
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
| |
Collapse
|
26
|
Yang Y, Cápiro NL, Marcet TF, Yan J, Pennell KD, Löffler FE. Organohalide Respiration with Chlorinated Ethenes under Low pH Conditions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:8579-8588. [PMID: 28665587 DOI: 10.1021/acs.est.7b01510] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Bioremediation at chlorinated solvent sites often leads to groundwater acidification due to electron donor fermentation and enhanced dechlorination activity. The microbial reductive dechlorination process is robust at circumneutral pH, but activity declines at groundwater pH values below 6.0. Consistent with this observation, the activity of tetrachloroethene (PCE) dechlorinating cultures declined at pH 6.0 and was not sustained in pH 5.5 medium, with one notable exception. Sulfurospirillum multivorans dechlorinated PCE to cis-1,2-dichloroethene (cDCE) in pH 5.5 medium and maintained this activity upon repeated transfers. Microcosms established with soil and aquifer materials from five distinct locations dechlorinated PCE-to-ethene at pH 5.5 and pH 7.2. Dechlorination to ethene was maintained following repeated transfers at pH 7.2, but no ethene was produced at pH 5.5, and only the transfer cultures derived from the Axton Cross Superfund (ACS) microcosms sustained PCE dechlorination to cDCE as a final product. 16S rRNA gene amplicon sequencing of pH 7.2 and pH 5.5 ACS enrichments revealed distinct microbial communities, with the dominant dechlorinator being Dehalococcoides in pH 7.2 and Sulfurospirillum in pH 5.5 cultures. PCE-to-trichloroethene- (TCE-) and PCE-to-cDCE-dechlorinating isolates obtained from the ACS pH 5.5 enrichment shared 98.6%, and 98.5% 16S rRNA gene sequence similarities to Sulfurospirillum multivorans. These findings imply that sustained Dehalococcoides activity cannot be expected in low pH (i.e., ≤ 5.5) groundwater, and organohalide-respiring Sulfurospirillum spp. are key contributors to in situ PCE reductive dechlorination under low pH conditions.
Collapse
Affiliation(s)
| | - Natalie L Cápiro
- Department of Civil and Environmental Engineering, Tufts University , Medford, Massachusetts 02155, United States
| | - Tyler F Marcet
- Department of Civil and Environmental Engineering, Tufts University , Medford, Massachusetts 02155, United States
| | | | - Kurt D Pennell
- Department of Civil and Environmental Engineering, Tufts University , Medford, Massachusetts 02155, United States
| | | |
Collapse
|
27
|
Dolinová I, Štrojsová M, Černík M, Němeček J, Macháčková J, Ševců A. Microbial degradation of chloroethenes: a review. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:13262-13283. [PMID: 28378313 DOI: 10.1007/s11356-017-8867-y] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 03/17/2017] [Indexed: 05/28/2023]
Abstract
Contamination by chloroethenes has a severe negative effect on both the environment and human health. This has prompted intensive remediation activity in recent years, along with research into the efficacy of natural microbial communities for degrading toxic chloroethenes into less harmful compounds. Microbial degradation of chloroethenes can take place either through anaerobic organohalide respiration, where chloroethenes serve as electron acceptors; anaerobic and aerobic metabolic degradation, where chloroethenes are used as electron donors; or anaerobic and aerobic co-metabolic degradation, with chloroethene degradation occurring as a by-product during microbial metabolism of other growth substrates, without energy or carbon benefit. Recent research has focused on optimising these natural processes to serve as effective bioremediation technologies, with particular emphasis on (a) the diversity and role of bacterial groups involved in dechlorination microbial processes, and (b) detection of bacterial enzymes and genes connected with dehalogenation activity. In this review, we summarise the different mechanisms of chloroethene bacterial degradation suitable for bioremediation and provide a list of dechlorinating bacteria. We also provide an up-to-date summary of primers available for detecting functional genes in anaerobic and aerobic bacteria degrading chloroethenes metabolically or co-metabolically.
Collapse
Affiliation(s)
- Iva Dolinová
- Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of Liberec, Studentská 2, 461 17, Liberec, Czech Republic
- Faculty of Mechatronics, Informatics and Interdisciplinary Studies, Technical University of Liberec, Studentská 2, 461 17, Liberec, Czech Republic
| | - Martina Štrojsová
- Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of Liberec, Studentská 2, 461 17, Liberec, Czech Republic
| | - Miroslav Černík
- Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of Liberec, Studentská 2, 461 17, Liberec, Czech Republic
- Faculty of Mechatronics, Informatics and Interdisciplinary Studies, Technical University of Liberec, Studentská 2, 461 17, Liberec, Czech Republic
| | - Jan Němeček
- Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of Liberec, Studentská 2, 461 17, Liberec, Czech Republic
| | - Jiřina Macháčková
- Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of Liberec, Studentská 2, 461 17, Liberec, Czech Republic
| | - Alena Ševců
- Institute for Nanomaterials, Advanced Technologies and Innovation, Technical University of Liberec, Studentská 2, 461 17, Liberec, Czech Republic.
- Faculty of Mechatronics, Informatics and Interdisciplinary Studies, Technical University of Liberec, Studentská 2, 461 17, Liberec, Czech Republic.
| |
Collapse
|
28
|
Kanitkar YH, Stedtfeld RD, Hatzinger PB, Hashsham SA, Cupples AM. Development and application of a rapid, user-friendly, and inexpensive method to detect Dehalococcoides sp. reductive dehalogenase genes from groundwater. Appl Microbiol Biotechnol 2017; 101:4827-4835. [PMID: 28238079 DOI: 10.1007/s00253-017-8203-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Revised: 02/13/2017] [Accepted: 02/15/2017] [Indexed: 10/20/2022]
Abstract
TaqMan probe-based quantitative polymerase chain reaction (qPCR) specific to the biomarker reductive dehalogenase (RDase) genes is a widely accepted molecular biological tool (MBT) for determining the abundance of Dehalococcoides sp. in groundwater samples from chlorinated solvent-contaminated sites. However, there are significant costs associated with this MBT. In this study, we describe an approach that requires only low-cost laboratory equipment (a bench top centrifuge and a water bath) and requires less time and resources compared to qPCR. The method involves the concentration of biomass from groundwater, without DNA extraction, and loop-mediated isothermal amplification (LAMP) of the cell templates. The amplification products are detected by a simple visual color change (orange/green). The detection limits of the assay were determined using groundwater from a contaminated site. In addition, the assay was tested with groundwater from three additional contaminated sites. The final approach to detect RDase genes, without DNA extraction or a thermal cycler, was successful to 1.8 × 105 gene copies per L for vcrA and 1.3 × 105 gene copies per L for tceA. Both values are below the threshold recommended for effective in situ dechlorination.
Collapse
Affiliation(s)
- Yogendra H Kanitkar
- Department of Civil and Environmental Engineering, Michigan State University, A135, 1449 Engineering Research Court, East Lansing, MI, 48824, USA
| | - Robert D Stedtfeld
- Department of Civil and Environmental Engineering, Michigan State University, A135, 1449 Engineering Research Court, East Lansing, MI, 48824, USA
| | - Paul B Hatzinger
- CB&I Federal Services, 17 Princess Road, Lawrenceville, NJ, 08648, USA
| | - Syed A Hashsham
- Department of Civil and Environmental Engineering, Michigan State University, A135, 1449 Engineering Research Court, East Lansing, MI, 48824, USA.,Center for Microbial Ecology, Michigan State University, East Lansing, MI, USA
| | - Alison M Cupples
- Department of Civil and Environmental Engineering, Michigan State University, A135, 1449 Engineering Research Court, East Lansing, MI, 48824, USA.
| |
Collapse
|
29
|
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
|
30
|
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.
Collapse
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
| |
Collapse
|
31
|
Kanitkar YH, Stedtfeld RD, Steffan RJ, Hashsham SA, Cupples AM. Loop-Mediated Isothermal Amplification (LAMP) for Rapid Detection and Quantification of Dehalococcoides Biomarker Genes in Commercial Reductive Dechlorinating Cultures KB-1 and SDC-9. Appl Environ Microbiol 2016; 82:1799-1806. [PMID: 26746711 PMCID: PMC4784023 DOI: 10.1128/aem.03660-15] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 12/27/2015] [Indexed: 12/23/2022] Open
Abstract
Real-time quantitative PCR (qPCR) protocols specific to the reductive dehalogenase (RDase) genes vcrA, bvcA, and tceA are commonly used to quantify Dehalococcoides spp. in groundwater from chlorinated solvent-contaminated sites. In this study, loop-mediated isothermal amplification (LAMP) was developed as an alternative approach for the quantification of these genes. LAMP does not require a real-time thermal cycler (i.e., amplification is isothermal), allowing the method to be performed using less-expensive and potentially field-deployable detection devices. Six LAMP primers were designed for each of three RDase genes (vcrA, bvcA, and tceA) using Primer Explorer V4. The LAMP assays were compared to conventional qPCR approaches using plasmid standards, two commercially available bioaugmentation cultures, KB-1 and SDC-9 (both contain Dehalococcoides species). DNA was extracted over a growth cycle from KB-1 and SDC-9 cultures amended with trichloroethene and vinyl chloride, respectively. All three genes were quantified for KB-1, whereas only vcrA was quantified for SDC-9. A comparison of LAMP and qPCR using standard plasmids indicated that quantification results were similar over a large range of gene concentrations. In addition, the quantitative increase in gene concentrations over one growth cycle of KB-1 and SDC-9 using LAMP was comparable to that of qPCR. The developed LAMP assays for vcrA and tceA genes were validated by comparing quantification on the Gene-Z handheld platform and a real-time thermal cycler using DNA isolated from eight groundwater samples obtained from an SDC-9-bioaugmented site (Tulsa, OK). These assays will be particularly useful at sites subject to bioaugmentation with these two commonly used Dehalococcoides species-containing cultures.
Collapse
Affiliation(s)
- Yogendra H Kanitkar
- Department of Civil and Environmental Engineering, Michigan State University, East Lansing, Michigan, USA
| | - Robert D Stedtfeld
- Department of Civil and Environmental Engineering, Michigan State University, East Lansing, Michigan, USA
| | - Robert J Steffan
- Biotechnology Development and Applications Group, CB&I Federal Services, LLC, Lawrenceville, New Jersey, USA
| | - Syed A Hashsham
- Department of Civil and Environmental Engineering, Michigan State University, East Lansing, Michigan, USA
- Center for Microbial Ecology, Michigan State University, East Lansing, Michigan, USA
| | - Alison M Cupples
- Department of Civil and Environmental Engineering, Michigan State University, East Lansing, Michigan, USA
| |
Collapse
|
32
|
Adetutu EM, Gundry TD, Patil SS, Golneshin A, Adigun J, Bhaskarla V, Aleer S, Shahsavari E, Ross E, Ball AS. Exploiting the intrinsic microbial degradative potential for field-based in situ dechlorination of trichloroethene contaminated groundwater. JOURNAL OF HAZARDOUS MATERIALS 2015; 300:48-57. [PMID: 26151384 DOI: 10.1016/j.jhazmat.2015.06.055] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 06/21/2015] [Accepted: 06/22/2015] [Indexed: 06/04/2023]
Abstract
Bioremediation of trichloroethene (TCE) polluted groundwater is challenging, with limited next generation sequencing (NGS) derived information available on microbial community dynamics associated with dechlorination. Understanding these dynamics is important for designing and improving TCE bioremediation. In this study, biostimulation (BS), biostimulation-bioaugmentation (BS-BA) and monitored natural attenuation (MNA) approaches were applied to contaminated groundwater wells resulted in ≥ 95% dechlorination within 7 months. Vinyl chloride's final concentrations in stimulated wells were between 1.84 and 1.87 μg L(-1), below the US EPA limit of 2.0 μg L(-1), compared to MNA (4.3 μg L(-1)). Assessment of the groundwater microbial community with qPCR showed up to ∼ 50-fold increase in the classical dechlorinators' (Geobacter and Dehalococcoides sp.) population post-treatment. Metagenomic assays revealed shifts from Gammaproteobacteria (pre-treatment) to Epsilonproteobacteria and Deltaproteobacteria (post-treatment) only in stimulated wells. Although stimulated wells were functionally distinct from MNA wells post-treatment, substantial dechlorination in all the wells implied some measure of redundancy. This study, one of the few NGS-based field studies on TCE bioremediation, provides greater insights into dechlorinating microbial community dynamics which should be useful for future field-based studies.
Collapse
Affiliation(s)
- Eric M Adetutu
- School of Applied Sciences, Royal Melbourne Institute of Technology, Bundoora, Melbourne, VIC 3083, Australia
| | - Taylor D Gundry
- School of Applied Sciences, Royal Melbourne Institute of Technology, Bundoora, Melbourne, VIC 3083, Australia.
| | - Sayali S Patil
- School of Applied Sciences, Royal Melbourne Institute of Technology, Bundoora, Melbourne, VIC 3083, Australia; School of Biological Sciences, Flinders University of South Australia, Adelaide, SA 5042, Australia
| | - Aida Golneshin
- School of Applied Sciences, Royal Melbourne Institute of Technology, Bundoora, Melbourne, VIC 3083, Australia
| | - Joy Adigun
- GeneDX, 207 Perry Parkway, Gaithersburg, MD 20877, USA
| | - Vijay Bhaskarla
- School of Applied Sciences, Royal Melbourne Institute of Technology, Bundoora, Melbourne, VIC 3083, Australia
| | - Samuel Aleer
- School of Applied Sciences, Royal Melbourne Institute of Technology, Bundoora, Melbourne, VIC 3083, Australia
| | - Esmaeil Shahsavari
- School of Applied Sciences, Royal Melbourne Institute of Technology, Bundoora, Melbourne, VIC 3083, Australia
| | - Elizabeth Ross
- The University of Melbourne, Faculty of Veterinary and Agricultural Sciences, Parkville, VIC, Australia
| | - Andrew S Ball
- School of Applied Sciences, Royal Melbourne Institute of Technology, Bundoora, Melbourne, VIC 3083, Australia
| |
Collapse
|
33
|
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.
Collapse
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.
| |
Collapse
|
34
|
Laboratory evaluation of bioaugmentation for aerobic treatment of RDX in groundwater. Biodegradation 2014; 26:77-89. [DOI: 10.1007/s10532-014-9717-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Accepted: 12/06/2014] [Indexed: 10/24/2022]
|
35
|
Stedtfeld RD, Stedtfeld TM, Kronlein M, Seyrig G, Steffan RJ, Cupples AM, Hashsham SA. DNA extraction-free quantification of Dehalococcoides spp. in groundwater using a hand-held device. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:13855-63. [PMID: 25360694 DOI: 10.1021/es503472h] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Nucleic acid amplification of biomarkers is increasingly used to measure microbial activity and predict remedial performance in sites with trichloroethene (TCE) contamination. Field-based genetic quantification of microorganisms associated with bioremediation may help increase accuracy that is diminished through transport and processing of groundwater samples. Sterivex cartridges and a previously undescribed mechanism for eluting biomass was used to concentrate cells. DNA extraction-free loop mediated isothermal amplification (LAMP) was monitored in real-time with a point of use device (termed Gene-Z). A detection limit of 10(5) cells L(–1) was obtained, corresponding to sensitivity between 10 to 100 genomic copies per reaction for assays targeting the Dehalococcoides spp. specific 16S rRNA gene and vcrA gene, respectively. The quantity of Dehalococcoides spp. genomic copies measured from two TCE contaminated groundwater samples with conventional means of quantification including filtration, DNA extraction, purification, and qPCR was comparable to the field ready technique. Overall, this method of measuring Dehalococcoides spp. and vcrA genes in groundwater via direct amplification without intentional DNA extraction and purification is demonstrated, which may provide a more accurate mechanism of predicting remediation rates.
Collapse
Affiliation(s)
- Robert D Stedtfeld
- Department of Civil and Environmental Engineering, Michigan State University, East Lansing, Michigan 48824, United States
| | | | | | | | | | | | | |
Collapse
|
36
|
Shan H, Wang H, Yu R, Jacob P, Freedman DL. Biodegradation of high concentrations of halomethanes by a fermentative enrichment culture. AMB Express 2014; 4:48. [PMID: 25401061 PMCID: PMC4230812 DOI: 10.1186/s13568-014-0048-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 05/14/2014] [Indexed: 11/20/2022] Open
Abstract
A fermentative enrichment culture (designated DHM-1) that grows on corn syrup was evaluated for its ability to cometabolically biodegrade high concentrations of chloroform (CF), carbon tetrachloride (CT), and trichlorofluoromethane (CFC-11). When provided with corn syrup and vitamin B12 (0.03 mol B12 per mol CF), DHM-1 grew and biodegraded up to 2,000 mg/L of CF in 180 days, with only minor transient accumulation of dichloromethane and chloromethane. CT (15 mg/L) and CFC-11 (25 mg/L) were also biodegraded without significant accumulation of halomethane daughter products. The rate of CF biodegradation followed a Michaelis-Menten-like pattern with respect to the B12 concentration; one-half the maximum rate (66 mg CF/L/d) occurred at 0.005 mol B12 per mol CF. DHM-1 was able to biodegrade 500 mg/L of CF at an inoculum level as low as 10−8 mg protein/L. The highest rate of CF biodegradation occurred at pH 7.7; activity decreased substantially below pH 6.0. DHM-1 biodegraded mixtures of CT, CFC-11, and CF, although CFC-11 inhibited CF biodegradation. Evidence for compete defluorination of CFC-11 was obtained based on a fluoride mass balance. Overall, the results suggest that DHM-1 may be effective for bioaugmentation in source zones contaminated with thousands of milligrams per liter of CF and tens of milligrams per liter of CT and CFC-11.
Collapse
|
37
|
Paul L, Smolders E. Inhibition of iron (III) minerals and acidification on the reductive dechlorination of trichloroethylene. CHEMOSPHERE 2014; 111:471-7. [PMID: 24997954 DOI: 10.1016/j.chemosphere.2014.04.057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 04/04/2014] [Accepted: 04/18/2014] [Indexed: 05/25/2023]
Abstract
Reductive dechlorination of chlorinated ethenes is inhibited by acidification and by the presence of Fe (III) as a competitive electron acceptor. Synergism between both factors on dechlorination is predicted as reductive dissolution of Fe (III) minerals is facilitated by acidification. This study was set-up to assess this synergism for two common aquifer Fe (III) minerals, goethite and ferrihydrite. Anaerobic microbial dechlorination of trichloroethylene (TCE) by KB-1 culture and formate as electron donor was investigated in anaerobic batch containers at different solution pH values (6.2-7.2) in sand coated with these Fe minerals and a sand only as control. In the absence of Fe, lowering substrate pH from 7.2 to 6.2 increased the time for 90% TCE degradation from 14±1d to 42±4d. At pH 7.2, goethite did not affect TCE degradation time while ferrihydrite increased the degradation time to 19±1d compared to the no Fe control. At pH 6.2, 90% degradation was at 78±1 (ferrihydrite) or 131±1d (goethite). Ferrous iron production in ferrihydrite treatment increased between pH 7.2 and 6.5 but decreased by further lowering pH to 6.2, likely due to reduced microbial activity. This study confirms that TCE is increasingly inhibited by the combined effect of acidification and bioavailable Fe (III), however no evidence was found for synergistic inhibition since Fe reduction did not increase as pH decreases. To the best of our knowledge, this is the first study where effect of pH and Fe (III) reduction on TCE was simultaneously tested. Acid Fe-rich aquifers need sufficient buffering and alkalinity to ensure swift degradation of chlorinated ethenes.
Collapse
Affiliation(s)
- Laiby Paul
- Division of Soil and Water Management, Department of Earth and Environmental Sciences, KU Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee, Belgium.
| | - Erik Smolders
- Division of Soil and Water Management, Department of Earth and Environmental Sciences, KU Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee, Belgium.
| |
Collapse
|
38
|
Danko AS, Fontenete SJ, de Aquino Leite D, Leitão PO, Almeida C, Schaefer CE, Vainberg S, Steffan RJ, Azevedo NF. Detection of Dehalococcoides spp. by peptide nucleic acid fluorescent in situ hybridization. J Mol Microbiol Biotechnol 2014; 24:142-9. [PMID: 24970105 DOI: 10.1159/000362790] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Chlorinated solvents including tetrachloroethene (perchloroethene and trichloroethene), are widely used industrial solvents. Improper use and disposal of these chemicals has led to a widespread contamination. Anaerobic treatment technologies that utilize Dehalococcoides spp. can be an effective tool to remediate these contaminated sites. Therefore, the aim of this study was to develop, optimize and validate peptide nucleic acid (PNA) probes for the detection of Dehalococcoides spp. in both pure and mixed cultures. PNA probes were designed by adapting previously published DNA probes targeting the region of the point mutations described for discriminating between the Dehalococcoides spp. strain CBDB1 and strain 195 lineages. Different fixation, hybridization and washing procedures were tested. The results indicated that the PNA probes hybridized specifically and with a high sensitivity to their corresponding lineages, and that the PNA probes developed during this work can be used in a duplex assay to distinguish between strain CBDB1 and strain 195 lineages, even in complex mixed cultures. This work demonstrates the effectiveness of using PNA fluorescence in situ hybridization to distinguish between two metabolically and genetically distinct Dehalococcoides strains, and they can have strong implications in the monitoring and differentiation of Dehalococcoides populations in laboratory cultures and at contaminated sites.
Collapse
Affiliation(s)
- Anthony S Danko
- Centro de Investigação em Geo-Ambiente e Recursos (CIGAR), Departamento de Engenharia de Minas, Faculdade de Engenharia, Porto, Portugal
| | | | | | | | | | | | | | | | | |
Collapse
|
39
|
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.
Collapse
|
40
|
Lacroix E, Brovelli A, Maillard J, Rohrbach-Brandt E, Barry DA, Holliger C. Use of silicate minerals for long-term pH control during reductive dechlorination of high tetrachloroethene concentrations in continuous flow-through columns. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 482-483:23-35. [PMID: 24636885 DOI: 10.1016/j.scitotenv.2014.02.099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 02/12/2014] [Accepted: 02/21/2014] [Indexed: 06/03/2023]
Abstract
The long-term buffering potential of three silicate minerals (diopside, fayalite and forsterite) present as fine particles in porous quartz sand medium was evaluated in flow-through column experiments over a period of 6.5 months. The columns were operated with PCE concentrations close to saturation and inoculated with the organohalide-respiring consortium SDC-9™, which is able to completely dechlorinate PCE to ethene at high concentrations. In the absence of pH buffering agents, fermentation and organohalide respiration drove the pH close to 6.1, leading to severe inhibition of PCE dechlorination. Forsterite and fayalite were able to maintain the pH close to 7.5 and 6.5, respectively, and to sustain the production of VC and ethene. Diopside gradually lost its buffering capacity during the first 84 days due to the formation of a low reactive leached layer but dechlorination to cis-DCE was still achieved. Among the three minerals tested, forsterite was identified as the best buffering agent. Its presence led to the best PCE removal performance and the highest relative abundance of Dehalococcoides. This study showed that forsterite and fayalite are promising sources of long-term pH buffering for in situ bioremediation of source-zone PCE.
Collapse
Affiliation(s)
- Elsa Lacroix
- Ecole Polytechnique Fédérale de Lausanne (EPFL), School of Architecture, Civil and Environmental Engineering (ENAC), Ecological Engineering Laboratory, Lausanne, Switzerland; Ecole Polytechnique Fédérale de Lausanne (EPFL), School of Architecture, Civil and Environmental Engineering (ENAC), Laboratory for Environmental Biotechnology, Lausanne, Switzerland
| | - Alessandro Brovelli
- Ecole Polytechnique Fédérale de Lausanne (EPFL), School of Architecture, Civil and Environmental Engineering (ENAC), Ecological Engineering Laboratory, Lausanne, Switzerland
| | - Julien Maillard
- Ecole Polytechnique Fédérale de Lausanne (EPFL), School of Architecture, Civil and Environmental Engineering (ENAC), Laboratory for Environmental Biotechnology, Lausanne, Switzerland
| | - Emmanuelle Rohrbach-Brandt
- Ecole Polytechnique Fédérale de Lausanne (EPFL), School of Architecture, Civil and Environmental Engineering (ENAC), Laboratory for Environmental Biotechnology, Lausanne, Switzerland
| | - D A Barry
- Ecole Polytechnique Fédérale de Lausanne (EPFL), School of Architecture, Civil and Environmental Engineering (ENAC), Ecological Engineering Laboratory, Lausanne, Switzerland
| | - Christof Holliger
- Ecole Polytechnique Fédérale de Lausanne (EPFL), School of Architecture, Civil and Environmental Engineering (ENAC), Laboratory for Environmental Biotechnology, Lausanne, Switzerland.
| |
Collapse
|
41
|
Lacroix E, Brovelli A, Holliger C, Barry DA. Control of groundwater pH during bioremediation: improvement and validation of a geochemical model to assess the buffering potential of ground silicate minerals. JOURNAL OF CONTAMINANT HYDROLOGY 2014; 160:21-29. [PMID: 24589423 DOI: 10.1016/j.jconhyd.2014.01.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2013] [Revised: 01/20/2014] [Accepted: 01/22/2014] [Indexed: 06/03/2023]
Abstract
Accurate control of groundwater pH is of critical importance for in situ biological treatment of chlorinated solvents. The use of ground silicate minerals mixed with groundwater is an appealing buffering strategy as silicate minerals may act as long-term sources of alkalinity. In a previous study, we developed a geochemical model for evaluation of the pH buffering capacity of such minerals. The model included the main microbial processes driving groundwater acidification as well as mineral dissolution. In the present study, abiotic mineral dissolution experiments were conducted with five silicate minerals (andradite, diopside, fayalite, forsterite, nepheline). The goal of the study was to validate the model and to test the buffering capacity of the candidate minerals identified previously. These five minerals increased the pH from acidic to neutral and slightly basic values. The model was revised and improved to represent better the experimental observations. In particular, the experiments revealed the importance of secondary mineral precipitation on the buffering potential of silicates, a process not included in the original formulation. The main secondary phases likely to precipitate were identified through model calibration, as well as the degree of saturation at which they formed. The predictions of the revised geochemical model were in good agreement with the observations, with a correlation coefficient higher than 0.9 in most cases. This study confirmed the potential of silicates to act as pH control agents and showed the reliability of the geochemical model, which can be used as a design tool for field applications.
Collapse
Affiliation(s)
- Elsa Lacroix
- Ecole Polytechnique Fédérale de Lausanne (EPFL), School of Architecture, Civil and Environmental Engineering (ENAC), Ecological Engineering Laboratory, Station 2, 1015 Lausanne, Switzerland; Ecole Polytechnique Fédérale de Lausanne (EPFL), School of Architecture, Civil and Environmental Engineering (ENAC), Laboratory for Environmental Biotechnology, Station 6, 1015 Lausanne, Switzerland
| | - Alessandro Brovelli
- Ecole Polytechnique Fédérale de Lausanne (EPFL), School of Architecture, Civil and Environmental Engineering (ENAC), Ecological Engineering Laboratory, Station 2, 1015 Lausanne, Switzerland
| | - Christof Holliger
- Ecole Polytechnique Fédérale de Lausanne (EPFL), School of Architecture, Civil and Environmental Engineering (ENAC), Laboratory for Environmental Biotechnology, Station 6, 1015 Lausanne, Switzerland.
| | - D A Barry
- Ecole Polytechnique Fédérale de Lausanne (EPFL), School of Architecture, Civil and Environmental Engineering (ENAC), Ecological Engineering Laboratory, Station 2, 1015 Lausanne, Switzerland
| |
Collapse
|
42
|
Use of silicate minerals for pH control during reductive dechlorination of chloroethenes in batch cultures of different microbial consortia. Appl Environ Microbiol 2014; 80:3858-67. [PMID: 24747895 DOI: 10.1128/aem.00493-14] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In chloroethene-contaminated sites undergoing in situ bioremediation, groundwater acidification is a frequent problem in the source zone, and buffering strategies have to be implemented to maintain the pH in the neutral range. An alternative to conventional soluble buffers is silicate mineral particles as a long-term source of alkalinity. In previous studies, the buffering potentials of these minerals have been evaluated based on abiotic dissolution tests and geochemical modeling. In the present study, the buffering potentials of four silicate minerals (andradite, diopside, fayalite, and forsterite) were tested in batch cultures amended with tetrachloroethene (PCE) and inoculated with different organohalide-respiring consortia. Another objective of this study was to determine the influence of pH on the different steps of PCE dechlorination. The consortia showed significant differences in sensitivities toward acidic pH for the different dechlorination steps. Molecular analysis indicated that Dehalococcoides spp. that were present in all consortia were the most pH-sensitive organohalide-respiring guild members compared to Sulfurospirillum spp. and Dehalobacter spp. In batch cultures with silicate mineral particles as pH-buffering agents, all four minerals tested were able to maintain the pH in the appropriate range for reductive dechlorination of chloroethenes. However, complete dechlorination to ethene was observed only with forsterite, diopside, and fayalite. Dissolution of andradite increased the redox potential and did not allow dechlorination. With forsterite, diopside, and fayalite, dechlorination to ethene was observed but at much lower rates for the last two dechlorination steps than with the positive control. This indicated an inhibition effect of silicate minerals and/or their dissolution products on reductive dechlorination of cis-dichloroethene and vinyl chloride. Hence, despite the proven pH-buffering potential of silicate minerals, compatibility with the bacterial community involved in in situ bioremediation has to be carefully evaluated prior to their use for pH control at a specific site.
Collapse
|
43
|
Hiortdahl KM, Borden RC. Enhanced reductive dechlorination of tetrachloroethene dense nonaqueous phase liquid with EVO and Mg(OH)2. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 48:624-631. [PMID: 24328264 DOI: 10.1021/es4042379] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In situ treatment of dense nonaqueous phase liquids (DNAPL) by enhanced reductive dechlorination (ERD) can be limited by contaminant toxicity, low pH, and challenges in effectively delivering electron donor. Flushing emulsified vegetable oil (EVO), colloidal Mg(OH)2 buffer, and a bioaugmentation culture (BC) through a zone containing neat tetrachloroethene (PCE) was effective in reducing contaminant toxicity, limiting pH declines, and accelerating bioenhanced dissolution of the DNAPL. In the effluent of porous media columns with little fine material, PCE concentrations reached a maximum of 40-50 times PCE aqueous solubility in water, demonstrating NAPL PCE was distributed throughout the 1.5 m column length. In a column treated with only EVO+BC, reductive dechlorination was limited. However, a single injection of EVO+Mg(OH)2+BC was effective in reducing PCE to below detection for over 400 days with a large increase in Cl(-) and dichloroethene (DCE), accelerating bioenhanced DNAPL dissolution. Dechlorination rates gradually increased over time with the rate of total ethene (TE) release from the Mg(OH)2+EVO+BC column reaching 5-6 times the TE release rate from the EVO+BC column. The accelerated dechlorination was likely due to both Mg(OH)2 addition which limited pH declines from HCl, volatile fatty acids (VFAs), and inorganic carbon (IC) production, and formation of a mixed PCE-vegetable oil NAPL which provided a readily accessible electron donor, resulting in rapid PCE degradation with reduced PCE toxicity.
Collapse
Affiliation(s)
- Kirsten M Hiortdahl
- Department of Civil, Construction and Environmental Engineering, North Carolina State University , Raleigh, North Carolina 27695, United States
| | | |
Collapse
|
44
|
Delgado AG, Fajardo-Williams D, Popat SC, Torres CI, Krajmalnik-Brown R. Successful operation of continuous reactors at short retention times results in high-density, fast-rate Dehalococcoides dechlorinating cultures. Appl Microbiol Biotechnol 2013; 98:2729-37. [PMID: 24085396 DOI: 10.1007/s00253-013-5263-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 09/11/2013] [Accepted: 09/12/2013] [Indexed: 10/26/2022]
Abstract
The discovery of Dehalococcoides mccartyi reducing perchloroethene and trichloroethene (TCE) to ethene was a key landmark for bioremediation applications at contaminated sites. D. mccartyi-containing cultures are typically grown in batch-fed reactors. On the other hand, continuous cultivation of these microorganisms has been described only at long hydraulic retention times (HRTs). We report the cultivation of a representative D. mccartyi-containing culture in continuous stirred-tank reactors (CSTRs) at a short, 3-d HRT, using TCE as the electron acceptor. We successfully operated 3-d HRT CSTRs for up to 120 days and observed sustained dechlorination of TCE at influent concentrations of 1 and 2 mM TCE to ≥ 97 % ethene, coupled to the production of 10(12) D. mccartyi cells Lculture (-1). These outcomes were possible in part by using a medium with low bicarbonate concentrations (5 mM) to minimize the excessive proliferation of microorganisms that use bicarbonate as an electron acceptor and compete with D. mccartyi for H2. The maximum conversion rates for the CSTR-produced culture were 0.13 ± 0.016, 0.06 ± 0.018, and 0.02 ± 0.007 mmol Cl(-) Lculture (-1) h(-1), respectively, for TCE, cis-dichloroethene, and vinyl chloride. The CSTR operation described here provides the fastest laboratory cultivation rate of high-cell density Dehalococcoides cultures reported in the literature to date. This cultivation method provides a fundamental scientific platform for potential future operations of such a system at larger scales.
Collapse
Affiliation(s)
- Anca G Delgado
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, P.O. Box 875701, Tempe, AZ, 85287-5701, USA,
| | | | | | | | | |
Collapse
|
45
|
Large-scale bioreactor production of the herbicide-degrading Aminobacter sp. strain MSH1. Appl Microbiol Biotechnol 2013; 98:2335-44. [DOI: 10.1007/s00253-013-5202-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Revised: 08/16/2013] [Accepted: 08/17/2013] [Indexed: 10/26/2022]
|
46
|
Kotik M, Davidová A, Voříšková J, Baldrian P. Bacterial communities in tetrachloroethene-polluted groundwaters: a case study. THE SCIENCE OF THE TOTAL ENVIRONMENT 2013; 454-455:517-527. [PMID: 23567172 DOI: 10.1016/j.scitotenv.2013.02.082] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Revised: 02/25/2013] [Accepted: 02/25/2013] [Indexed: 06/02/2023]
Abstract
The compositions of bacterial groundwater communities of three sites contaminated with chlorinated ethenes were analyzed by pyrosequencing their 16S rRNA genes. For each location, the entire and the active bacterial populations were characterized by independent molecular analysis of the community DNA and RNA. The sites were selected to cover a broad range of different environmental conditions and contamination levels, with tetrachloroethene (PCE) and trichloroethene (TCE) being the primary contaminants. Before sampling the biomass, a long-term monitoring of the polluted locations revealed high concentrations of cis-1,2-dichloroethene (cDCE) and vinyl chloride (VC), which are toxic by-products of the incomplete bacterial degradation of PCE and TCE. The applied pyrosequencing technique enabled known dechlorinators to be identified at a very low detection level (<0.25%) without compromising the detailed analysis of the entire bacterial community of these sites. The study revealed that only a few species dominated the bacterial communities, with Albidiferax ferrireducens being the only highly prominent member found at all three sites. Only a limited number of OTUs with abundances of up to 1% and high sequence identities to known dechlorinating microorganisms were retrieved from the RNA pools of the two highly contaminated sites. The dechlorinating consortium was likely to be comprised of cDCE-assimilating bacteria (Polaromonas spp.), anaerobic organohalide respirers (mainly Geobacter spp.), and Burkholderia spp. involved in cometabolic dechlorination processes, together with methylotrophs (Methylobacter spp.). The deep sequencing results suggest that the indigenous dechlorinating consortia present at the investigated sites can be used as a starting point for future bioremediation activities by stimulating their anaerobic and aerobic chloroethene degradation capacities (i.e. reductive dechlorination, and metabolic and cometabolic oxidation).
Collapse
Affiliation(s)
- Michael Kotik
- Laboratory of Biotransformation, Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20 Prague 4, Czech Republic.
| | | | | | | |
Collapse
|
47
|
Sowers KR, May HD. In situ treatment of PCBs by anaerobic microbial dechlorination in aquatic sediment: are we there yet? Curr Opin Biotechnol 2013; 24:482-8. [PMID: 23102490 PMCID: PMC3572274 DOI: 10.1016/j.copbio.2012.10.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2012] [Revised: 09/14/2012] [Accepted: 10/03/2012] [Indexed: 11/29/2022]
Abstract
The remediation of polychlorinated biphenyls (PCBs) in soils and sediments remains a particularly difficult problem to solve. The possibility of in situ degradation by microorganisms has been pursued for many years since this approach has the potential to provide a cost-effective and environmentally sustainable alternative to dredging for treatment of PCB impacted sites. Being hydrophobic, PCBs partition into organic material and accumulate in anoxic environments well poised to support anaerobic dechlorination of highly chlorinated congeners; products of which are susceptible to complete aerobic degradation. Laboratory research over the past 25 years is now leading to new microbial technologies that could soon be tested for treatment of PCB impacted sediments in the field.
Collapse
Affiliation(s)
- Kevin R Sowers
- Department of Marine Biotechnology, University of Maryland Baltimore County and Institute of Marine & Environmental Technology, University of Maryland, Baltimore, MD, USA
| | | |
Collapse
|
48
|
Philips J, Maes N, Springael D, Smolders E. Acidification due to microbial dechlorination near a trichloroethene DNAPL is overcome with pH buffer or formate as electron donor: experimental demonstration in diffusion-cells. JOURNAL OF CONTAMINANT HYDROLOGY 2013; 147:25-33. [PMID: 23500838 DOI: 10.1016/j.jconhyd.2013.02.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Revised: 01/08/2013] [Accepted: 02/01/2013] [Indexed: 06/01/2023]
Abstract
Acidification due to microbial dechlorination of trichloroethene (TCE) can limit the bio-enhanced dissolution of TCE dense non-aqueous phase liquid (DNAPL). This study related the dissolution enhancement of a TCE DNAPL to the pH buffer capacity of the medium and the type of electron donor used. In batch systems, dechlorination was optimal at pH7.1-7.5, but was completely inhibited below pH6.2. In addition, dechlorination in batch systems led to a smaller pH decrease at an increasing pH buffer capacity or with the use of formate instead of lactate as electron donor. Subsequently, bio-enhanced TCE DNAPL dissolution was quantified in diffusion-cells with a 5.5 cm central sand layer, separating a TCE DNAPL layer from an aqueous top layer. Three different pH buffer capacities (2.9 mM-17.9 mM MOPS) and lactate or formate as electron donor were applied. In the lactate fed diffusion-cells, the DNAPL dissolution enhancement factor increased from 1.5 to 2.2 with an increase of the pH buffer capacity. In contrast, in the formate fed diffusion-cells, the DNAPL dissolution enhancement factor (2.4±0.3) was unaffected by the pH buffer capacity. Measurement of the pore water pH confirmed that the pH decreased less with an increased pH buffer capacity or with formate instead of lactate as electron donor. These results suggest that the significant impact of acidification on bio-enhanced DNAPL dissolution can be overcome by the amendment of a pH buffer or by applying a non acidifying electron donor like formate.
Collapse
Affiliation(s)
- Jo Philips
- Department of Earth and Environmental Sciences, Division of Soil and Water Management, Katholieke Universiteit Leuven, Kasteelpark Arenberg 20, B-3001 Heverlee, Belgium.
| | | | | | | |
Collapse
|
49
|
Chambon JC, Bjerg PL, Scheutz C, Baelum J, Jakobsen R, Binning PJ. Review of reactive kinetic models describing reductive dechlorination of chlorinated ethenes in soil and groundwater. Biotechnol Bioeng 2012; 110:1-23. [DOI: 10.1002/bit.24714] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2012] [Revised: 08/13/2012] [Accepted: 08/16/2012] [Indexed: 11/08/2022]
|
50
|
Delgado AG, Parameswaran P, Fajardo-Williams D, Halden RU, Krajmalnik-Brown R. Role of bicarbonate as a pH buffer and electron sink in microbial dechlorination of chloroethenes. Microb Cell Fact 2012; 11:128. [PMID: 22974059 PMCID: PMC3511292 DOI: 10.1186/1475-2859-11-128] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Accepted: 09/04/2012] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Buffering to achieve pH control is crucial for successful trichloroethene (TCE) anaerobic bioremediation. Bicarbonate (HCO3-) is the natural buffer in groundwater and the buffer of choice in the laboratory and at contaminated sites undergoing biological treatment with organohalide respiring microorganisms. However, HCO3- also serves as the electron acceptor for hydrogenotrophic methanogens and hydrogenotrophic homoacetogens, two microbial groups competing with organohalide respirers for hydrogen (H2). We studied the effect of HCO3- as a buffering agent and the effect of HCO3--consuming reactions in a range of concentrations (2.5-30 mM) with an initial pH of 7.5 in H2-fed TCE reductively dechlorinating communities containing Dehalococcoides, hydrogenotrophic methanogens, and hydrogenotrophic homoacetogens. RESULTS Rate differences in TCE dechlorination were observed as a result of added varying HCO3- concentrations due to H2-fed electrons channeled towards methanogenesis and homoacetogenesis and pH increases (up to 8.7) from biological HCO3- consumption. Significantly faster dechlorination rates were noted at all HCO3- concentrations tested when the pH buffering was improved by providing 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) as an additional buffer. Electron balances and quantitative PCR revealed that methanogenesis was the main electron sink when the initial HCO3- concentrations were 2.5 and 5 mM, while homoacetogenesis was the dominant process and sink when 10 and 30 mM HCO3- were provided initially. CONCLUSIONS Our study reveals that HCO3- is an important variable for bioremediation of chloroethenes as it has a prominent role as an electron acceptor for methanogenesis and homoacetogenesis. It also illustrates the changes in rates and extent of reductive dechlorination resulting from the combined effect of electron donor competition stimulated by HCO3- and the changes in pH exerted by methanogens and homoacetogens.
Collapse
Affiliation(s)
- Anca G Delgado
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, PO Box 875001, Tempe, AZ 85287-5701, USA
- School of Life Sciences, Arizona State University, Tempe, USA
| | - Prathap Parameswaran
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, PO Box 875001, Tempe, AZ 85287-5701, USA
| | - Devyn Fajardo-Williams
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, PO Box 875001, Tempe, AZ 85287-5701, USA
| | - Rolf U Halden
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, PO Box 875001, Tempe, AZ 85287-5701, USA
- Ira A Fulton Schools of Engineering, Arizona State University, Tempe, USA
| | - Rosa Krajmalnik-Brown
- Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, PO Box 875001, Tempe, AZ 85287-5701, USA
- Ira A Fulton Schools of Engineering, Arizona State University, Tempe, USA
| |
Collapse
|