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Islam DT, Williams MR, Teppen BJ, Johnston CT, Li H, Boyd SA, Zylstra GJ, Fennell DE, Cupples AM, Hashsham SA. Comprehensive model for predicting toxic equivalents (TEQ) reduction due to dechlorination of polychlorinated dibenzo-p-dioxin and dibenzofurans (PCDD/F congeners). JOURNAL OF HAZARDOUS MATERIALS 2024; 480:135749. [PMID: 39276747 DOI: 10.1016/j.jhazmat.2024.135749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2024] [Revised: 07/17/2024] [Accepted: 09/03/2024] [Indexed: 09/17/2024]
Abstract
Remediation-focused predictive tools for polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) rely on transformation models to evaluate the reduction in total contaminant load and toxic equivalency (TEQ). In this study, a comprehensive model predicting the profiles of PCDD/F congeners and the associated TEQs was developed. The model employs first-order kinetics to describe the transformation of 256 reactions for 75 PCDD congeners and 421 reactions for 135 PCDF congeners. It integrates the growth of anaerobic microbial guilds using Monod kinetics on hydrogen release compounds and stoichiometric growth for Dehalococcoides sp. The effects of temperature, salinity, pH, and availability of vitamin B12 (a cofactor) were also integrated. The PCDD/F congeners model was used to extract the first-order dechlorination rate constants from a number of pure culture and mixed microbial microcosm studies. Simulations for the transformation of PCDD/F congeners at concentrations representative of the Tittabawassee or Saginaw Rivers and watershed in MI, USA were carried out. For a starting TEQ of 5000 ng per kg dry sediment (ppt), the model predicted a decrease in the overall TEQ to below 2000 ppt after 2.6 years and below 250 ppt after ∼21 years. The developed model may be used for extracting rates from microcosm studies and to evaluate the effect of engineering interventions on TEQ reduction.
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Affiliation(s)
- Dar Tafazul Islam
- Department of Civil and Environmental Engineering, Michigan State University, East Lansing, MI, USA
| | - Maggie R Williams
- School of Engineering and Technology, Institute for Great Lakes Research, Central Michigan University, Mount Pleasant, MI, USA
| | - Brian J Teppen
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, USA
| | - Cliff T Johnston
- Department of Agronomy, Purdue University, West Lafayette, IN, USA
| | - Hui Li
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, USA
| | - Stephen A Boyd
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, USA
| | - Gerben J Zylstra
- Department of Biochemistry & Microbiology, Rutgers University, New Brunswick, NJ, USA
| | - Donna E Fennell
- Department of Environmental Sciences, Rutgers University, New Brunswick, NJ, USA
| | - Alison M Cupples
- Department of Civil and Environmental Engineering, Michigan State University, East Lansing, MI, USA
| | - Syed A Hashsham
- Department of Civil and Environmental Engineering, Michigan State University, East Lansing, MI, USA.
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2
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Li ZT, Song X, Yuan S, Zhao HP. Unveiling the inhibitory mechanisms of chromium exposure on microbial reductive dechlorination: Kinetics and microbial responses. WATER RESEARCH 2024; 253:121328. [PMID: 38382292 DOI: 10.1016/j.watres.2024.121328] [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: 10/10/2023] [Revised: 02/14/2024] [Accepted: 02/15/2024] [Indexed: 02/23/2024]
Abstract
Chromium and organochlorine solvents, particularly trichloroethene (TCE), are pervasive co-existing contaminants in subsurface aquifers due to their extensive industrial use and improper disposal practices. In this study, we investigated the microbial dechlorination kinetics under different TCE-Cr(Ⅲ/VI) composite pollution conditions and elucidated microbial response mechanisms based on community shift patterns and metagenomic analysis. Our results revealed that the reductive dechlorinating consortium had high resistance to Cr(III) but extreme sensitivity to Cr(VI) disturbance, resulting in a persistent inhibitory effect on subsequent dechlorination. Interestingly, the vinyl chloride-respiring organohalide-respiring bacteria (OHRB) was notably more susceptible to Cr(III/VI) exposure than the trichloroethene-respiring one, possibly due to inferior competition for growth substrates, such as electron donors. In terms of synergistic non-OHRB populations, Cr(III/VI) exposure had limited impacts on lactate fermentation but significantly interfered with H2-producing acetogenesis, leading to inhibited microbial dechlorination due to electron donor deficiencies. However, this inhibition can be effectively mitigated by the amendment of exogenous H2 supply. Furthermore, being the predominant OHRB, Dehalococcoides have inherent Cr(VI) resistance defects and collaborate with synergistic non-OHRB populations to achieve concurrent bio-detoxication of Cr(VI) and TCE. Our findings expand the understanding of the response patterns of different functional populations towards Cr(III/VI) stress, and provide valuable insights for the development of in situ bioremediation strategies for sites co-contaminated with chloroethene and chromium.
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Affiliation(s)
- Zheng-Tao Li
- MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310030, PR China
| | - Xin Song
- CAS Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, PR China
| | - Songhu Yuan
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, No. 68 Jincheng Street, East Lake High-Tech Development Zone, Wuhan 430078, PR China
| | - He-Ping Zhao
- MOE Key Lab of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310030, PR China.
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3
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Chen G, Yang Y, Yan J, Löffler FE. Metabolite cross-feeding enables concomitant catabolism of chlorinated methanes and chlorinated ethenes in synthetic microbial assemblies. THE ISME JOURNAL 2024; 18:wrae090. [PMID: 38818735 PMCID: PMC11170663 DOI: 10.1093/ismejo/wrae090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 04/19/2024] [Accepted: 05/21/2024] [Indexed: 06/01/2024]
Abstract
Isolate studies have been a cornerstone for unraveling metabolic pathways and phenotypical (functional) features. Biogeochemical processes in natural and engineered ecosystems are generally performed by more than a single microbe and often rely on mutualistic interactions. We demonstrate the rational bottom-up design of synthetic, interdependent co-cultures to achieve concomitant utilization of chlorinated methanes as electron donors and organohalogens as electron acceptors. Specialized anaerobes conserve energy from the catabolic conversion of chloromethane or dichloromethane to formate, H2, and acetate, compounds that the organohalide-respiring bacterium Dehalogenimonas etheniformans strain GP requires to utilize cis-1,2-dichloroethenene and vinyl chloride as electron acceptors. Organism-specific qPCR enumeration matched the growth of individual dechlorinators to the respective functional (i.e. dechlorination) traits. The metabolite cross-feeding in the synthetic (co-)cultures enables concomitant utilization of chlorinated methanes (i.e. chloromethane and dichloromethane) and chlorinated ethenes (i.e. cis-1,2-dichloroethenene and vinyl chloride) without the addition of an external electron donor (i.e. formate and H2). The findings illustrate that naturally occurring chlorinated C1 compounds can sustain anaerobic food webs, an observation with implications for the development of interdependent, mutualistic communities, the sustenance of microbial life in oligotrophic and energy-deprived environments, and the fate of chloromethane/dichloromethane and chlorinated electron acceptors (e.g. chlorinated ethenes) in pristine environments and commingled contaminant plumes.
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Affiliation(s)
- Gao Chen
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN 37996, United States
| | - Yi Yang
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning 110016, China
| | - Jun Yan
- Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning 110016, China
| | - Frank E Löffler
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, TN 37996, United States
- Department of Microbiology, University of Tennessee, Knoxville, TN 37996, United States
- Department of Biosystems Engineering and Soil Science, University of Tennessee, Knoxville, TN 37996, United States
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4
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Zeppilli M, Yaqoubi H, Dell’Armi E, Lai A, Belfaquir M, Lorini L, Papini MP. Tetrachloroethane (TeCA) removal through sequential graphite-mixed metal oxide electrodes in a bioelectrochemical reactor. ENVIRONMENTAL SCIENCE AND ECOTECHNOLOGY 2024; 17:100309. [PMID: 37560753 PMCID: PMC10406622 DOI: 10.1016/j.ese.2023.100309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 07/10/2023] [Accepted: 07/22/2023] [Indexed: 08/11/2023]
Abstract
Electro-bioremediation offers a promising approach for eliminating persistent pollutants from groundwater since allows the stimulation of biological dechlorinating activity, utilizing renewable electricity for process operation and avoiding the injection of chemicals into aquifers. In this study, a two-chamber microbial electrolysis cell has been utilized to achieve both reductive and oxidative degradation of tetrachloroethane (TeCA). By polarizing the graphite granules cathodic chamber at -650 mV vs the standard hydrogen electrode and employing a mixed metal oxide (MMO) counter electrode for oxygen production, the reductive and oxidative environment necessary for TeCA removal has been established. Continuous experiments were conducted using two feeding solutions: an optimized mineral medium for dechlorinating microorganisms, and synthetic groundwater containing sulphate and nitrate anions to investigate potential side reactions. The bioelectrochemical process efficiently reduced TeCA to a mixture of trans-dichloroethylene, vinyl chloride, and ethylene, which were subsequently oxidized in the anodic chamber with removal efficiencies of 37 ± 2%, 100 ± 4%, and 100 ± 5%, respectively. The introduction of synthetic groundwater with nitrate and sulphate stimulated reductions in these ions in the cathodic chamber, leading to a 17% decrease in the reductive dechlorination rate and the appearance of other chlorinated by-products, including cis-dichloroethylene and 1,2-dichloroethane (1,2-DCA), in the cathode effluent. Notably, despite the lower reductive dechlorination rate during synthetic groundwater operation, aerobic dechlorinating microorganisms within the anodic chamber completely removed VC and 1,2-DCA. This study represents the first demonstration of a sequential reductive and oxidative bioelectrochemical process for TeCA mineralization in a synthetic solution simulating contaminated groundwater.
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Affiliation(s)
- Marco Zeppilli
- Department of Chemistry, University of Rome Sapienza, Piazzale Aldo Moro 5, Rome, 00185, Italy
| | - Hafsa Yaqoubi
- Department of Chemistry, Ibn Tofail University, Laboratory of Advanced Material and Process Engineering, Campus Universitaire, BP. 242, Kenitra, Morocco
| | - Edoardo Dell’Armi
- Department of Chemistry, University of Rome Sapienza, Piazzale Aldo Moro 5, Rome, 00185, Italy
| | - Agnese Lai
- Department of Chemistry, University of Rome Sapienza, Piazzale Aldo Moro 5, Rome, 00185, Italy
| | - Mustapha Belfaquir
- Department of Chemistry, Ibn Tofail University, Laboratory of Advanced Material and Process Engineering, Campus Universitaire, BP. 242, Kenitra, Morocco
| | - Laura Lorini
- Department of Chemistry, University of Rome Sapienza, Piazzale Aldo Moro 5, Rome, 00185, Italy
| | - Marco Petrangeli Papini
- Department of Chemistry, University of Rome Sapienza, Piazzale Aldo Moro 5, Rome, 00185, Italy
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5
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Romantschuk M, Lahti-Leikas K, Kontro M, Galitskaya P, Talvenmäki H, Simpanen S, Allen JA, Sinkkonen A. Bioremediation of contaminated soil and groundwater by in situ biostimulation. Front Microbiol 2023; 14:1258148. [PMID: 38029190 PMCID: PMC10658714 DOI: 10.3389/fmicb.2023.1258148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 09/22/2023] [Indexed: 12/01/2023] Open
Abstract
Bioremediation by in situ biostimulation is an attractive alternative to excavation of contaminated soil. Many in situ remediation methods have been tested with some success; however, due to highly variable results in realistic field conditions, they have not been implemented as widely as they might deserve. To ensure success, methods should be validated under site-analogous conditions before full scale use, which requires expertise and local knowledge by the implementers. The focus here is on indigenous microbial degraders and evaluation of their performance. Identifying and removing biodegradation bottlenecks for degradation of organic pollutants is essential. Limiting factors commonly include: lack of oxygen or alternative electron acceptors, low temperature, and lack of essential nutrients. Additional factors: the bioavailability of the contaminating compound, pH, distribution of the contaminant, and soil structure and moisture, and in some cases, lack of degradation potential which may be amended with bioaugmentation. Methods to remove these bottlenecks are discussed. Implementers should also be prepared to combine methods or use them in sequence. Chemical/physical means may be used to enhance biostimulation. The review also suggests tools for assessing sustainability, life cycle assessment, and risk assessment. To help entrepreneurs, decision makers, and methods developers in the future, we suggest founding a database for otherwise seldom reported unsuccessful interventions, as well as the potential for artificial intelligence (AI) to assist in site evaluation and decision-making.
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Affiliation(s)
- Martin Romantschuk
- Faculty of Biological and Environmental Sciences, University of Helsinki, Lahti, Finland
| | - Katariina Lahti-Leikas
- Faculty of Biological and Environmental Sciences, University of Helsinki, Lahti, Finland
| | - Merja Kontro
- Faculty of Biological and Environmental Sciences, University of Helsinki, Lahti, Finland
| | | | - Harri Talvenmäki
- Faculty of Biological and Environmental Sciences, University of Helsinki, Lahti, Finland
| | - Suvi Simpanen
- Faculty of Biological and Environmental Sciences, University of Helsinki, Lahti, Finland
| | - John A. Allen
- Faculty of Biological and Environmental Sciences, University of Helsinki, Lahti, Finland
| | - Aki Sinkkonen
- Natural Resources Institute Finland (Luke), Horticulture Technologies, Turku, Finland
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6
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Chen C, Xu G, He J. Substrate-dependent strategies to mitigate sulfate inhibition on microbial reductive dechlorination of polychlorinated biphenyls. CHEMOSPHERE 2023; 342:140063. [PMID: 37673179 DOI: 10.1016/j.chemosphere.2023.140063] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 08/30/2023] [Accepted: 09/02/2023] [Indexed: 09/08/2023]
Abstract
Sulfate widely co-exists with polychlorinated biphenyls (PCBs) at various concentrations in the subsurface environment. Previous studies have suggested that sulfate often hampers microbial degradation of aliphatic chlorinated solvents such as chloroethenes. However, the impact of sulfate on microbial reductive dechlorination of aromatic PCBs and the underlying mechanisms have received limited attention. Likewise, strategies to mitigate such inhibition remain scarce. Here we found that the mechanisms and mitigation strategies of sulfate inhibition on PCB dechlorination were substrate-dependent. Under electron donor-limiting conditions, even a low concentration of sulfate (2 mM) resulted in a decreased PCB dechlorination rate by 88.7% in a co-culture comprising Dehalococcoides mccartyi CG1 and the sulfate-reducing bacterium Desulfovibrio desulfuricans F1, an inhibition which was attributed to the competition for electron donor between sulfate reduction and PCB dechlorination. As expected, re-amendment of 5 mM lactate effectively re-initiated PCB dechlorination. However, in the presence of a higher concentration of sulfate (5 mM), the PCB dechlorination rate in the co-culture was 77.7% lower than in the control, even with excessive electron donor supply. This inhibition was linked to high concentration of sulfide (∼5 mM) produced from sulfate reduction, as suggested by high availability of electron donor, recovery of dechlorination activity after removal of sulfide, and negligible influence of sulfate on PCB dechlorination in the axenic culture of D. mccartyi CG1. Indeed, sulfide (>5 mM) was found to directly suppress expression of PCB-dechlorinating reductive dehalogenase gene. The highest transcriptional level of pcbA1 was 2.9 ± 0.3 transcripts·cell-1 in the presence of ∼5 mM sulfide, which was increased to 37.4 ± 5.0 transcripts·cell-1 when sulfide was removed. Under this scenario, introduction of ferrous salts (5 mM) efficiently alleviated sulfide inhibition on PCB dechlorination. Interestingly, the augmentation of methanogens in the co-culture was also effective in mitigating sulfide inhibition on PCB dechlorination, offering a new approach to protect Dehalococcoides under sulfide stress. Collectively, these findings deepen our understanding of the influence of sulfate on microbial reductive dechlorination of PCBs and contribute to developing appropriate strategies based on geochemical conditions to alleviate sulfate inhibition during bioremediation of PCB-contaminated sites.
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Affiliation(s)
- Chen Chen
- Department of Civil and Environmental Engineering, National University of Singapore, 117576, Singapore
| | - Guofang Xu
- Department of Civil and Environmental Engineering, National University of Singapore, 117576, Singapore
| | - Jianzhong He
- Department of Civil and Environmental Engineering, National University of Singapore, 117576, Singapore.
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7
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Feng H, Yang W, Zhang Y, Ding Y, Chen L, Kang Y, Huang H, Chen R. Electroactive microorganism-assisted remediation of groundwater contamination: Advances and challenges. BIORESOURCE TECHNOLOGY 2023; 377:128916. [PMID: 36940880 DOI: 10.1016/j.biortech.2023.128916] [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] [Received: 02/08/2023] [Revised: 03/11/2023] [Accepted: 03/15/2023] [Indexed: 06/18/2023]
Abstract
Groundwater contamination has become increasingly prominent, therefore, the development of efficient remediation technology is crucial for improving groundwater quality. Bioremediation is cost-effective and environmentally friendly, while coexisting pollutant stress can affect microbial processes, and the heterogeneous character of groundwater medium can induce bioavailability limitations and electron donor/acceptor imbalances. Electroactive microorganisms (EAMs) are advantageous in contaminated groundwater because of their unique bidirectional electron transfer mechanism, which allows them to use solid electrodes as electron donors/acceptors. However, the relatively low-conductivity groundwater environment is unfavorable for electron transfer, which becomes a bottleneck problem that limits the remediation efficiency of EAMs. Therefore, this study reviews the recent advances and challenges of EAMs applied in the groundwater environment with complex coexisting ions, heterogeneity, and low conductivity and proposes corresponding future directions.
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Affiliation(s)
- Huajun Feng
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, Zhejiang, China; College of Environment and Resources, Zhejiang A&F University, Hangzhou 311300, Zhejiang, China
| | - Wanyue Yang
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, Zhejiang, China
| | - Yifeng Zhang
- Department of Environmental Engineering, Technical University of Denmark, DK-2800 Lyngby, Denmark
| | - Yangcheng Ding
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, Zhejiang, China
| | - Long Chen
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, Zhejiang, China
| | - Ying Kang
- Zhejiang Ecological Environmental Monitoring Center, 117 Xueyuan Road, Hangzhou 310012, Zhejiang, China
| | - Huan Huang
- Zhejiang Ecological Environmental Monitoring Center, 117 Xueyuan Road, Hangzhou 310012, Zhejiang, China
| | - Ruya Chen
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018, Zhejiang, China.
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8
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Karadagli F, Marcus A, Rittmann BE. Microbiological hydrogen (H 2 ) thresholds in anaerobic continuous-flow systems: Effects of system characteristics. Biotechnol Bioeng 2023. [PMID: 37148477 DOI: 10.1002/bit.28415] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 03/20/2023] [Accepted: 04/24/2023] [Indexed: 05/08/2023]
Abstract
Hydrogen (H2 ) concentrations that were associated with microbiological respiratory processes (RPs) such as sulfate reduction and methanogenesis were quantified in continuous-flow systems (CFSs) (e.g., bioreactors, sediments). Gibbs free energy yield (ΔǴ ~ 0) of the relevant RP has been proposed to control the observed H2 concentrations, but most of the reported values do not align with the proposed energetic trends. Alternatively, we postulate that system characteristics of each experimental design influence all system components including H2 concentrations. To analyze this proposal, a Monod-based mathematical model was developed and used to design a gas-liquid bioreactor for hydrogenotrophic methanogenesis with Methanobacterium bryantii M.o.H. Gas-to-liquid H2 mass transfer, microbiological H2 consumption, biomass growth, methane formation, and Gibbs free energy yields were evaluated systematically. Combining model predictions and experimental results revealed that an initially large biomass concentration created transients during which biomass consumed [H2 ]L rapidly to the thermodynamic H2 -threshold (≤1 nM) that triggerred the microorganisms to stop H2 oxidation. With no H2 oxidation, continuous gas-to-liquid H2 transfer increased [H2 ]L to a level that signaled the methanogens to resume H2 oxidation. Thus, an oscillatory H2 -concentration profile developed between the thermodynamic H2 -threshold (≤1 nM) and a low [H2 ]L (~10 nM) that relied on the rate of gas-to-liquid H2 -transfer. The transient [H2 ]L values were too low to support biomass synthesis that could balance biomass losses through endogenous oxidation and advection; thus, biomass declined continuously and disappeared. A stable [H2 ]L (1807 nM) emerged as a result of abiotic H2 -balance between gas-to-liquid H2 transfer and H2 removal via advection of liquid-phase.
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Affiliation(s)
- Fatih Karadagli
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona, USA
| | - Andrew Marcus
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona, USA
- Skyology Inc., San Francisco, California, USA
| | - Bruce E Rittmann
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, Tempe, Arizona, USA
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9
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Tomita R, Yoshida N, Meng L. Formate: A promising electron donor to enhance trichloroethene-to-ethene dechlorination in Dehalococcoides-augmented groundwater ecosystems with minimal bacterial growth. CHEMOSPHERE 2022; 307:136080. [PMID: 35988762 DOI: 10.1016/j.chemosphere.2022.136080] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 08/05/2022] [Accepted: 08/14/2022] [Indexed: 06/15/2023]
Abstract
Various substrates have been used to stimulate habitat microbes in chloroethene-contaminated groundwater, however, the specific efficiency and minimum growth of microbes have rarely been studied. This study investigated the effects of seven substrates on trichloroethene (TCE) dechlorination by augmentation of groundwater with Dehalococcoides mccartyi NIT01 and its contribution to the microbial community. Three out of eight test groups completed dechlorination of 1 mM TCE-to-ethene in varying durations; groundwater supplemented with formate (FOR) required 78 days, whereas the microcosms with lactate (LAC) and citrate (CIT) required approximately twice as long (143 days). The calculated efficiency of how much produced H2 was used in dechlorination indicated a higher efficiency in FOR (36%) compared with LAC (1.9%) or CIT (2.9%). FOR showed lower microbial growth (3.4 × 105 copies/mL) than LAC (1.5 × 106) or CIT (4.4 × 106), and maintained a higher Shannon diversity index (5.65) than LAC (4.97) and CIT (4.30). The rapid and higher H2 transfer efficiency with lower bacterial growth by using formate was attributed to the slightly positive Gibbs free energy identified in H2 production requiring a H2-utilizer, lower carbon in the molecule, and adaptation to metabolic potential of the original groundwater microbiome. Formate is, therefore, a promising electron donor for rapid Dehalococcoides-augmented remediation with minimum bacterial growth. Sequential transferring of the FOR culture successfully maintained TCE-to-ethene dechlorination activity and enriched the members of genera Dehalococcoides (33%), Methanosphaerula (23%), Rectinema (13%), and Desulfitobacterium (5.6%). This suggests that formate is transferred to H2 and acetate, and provided to Dehalococcoides.
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Affiliation(s)
- Ryuya Tomita
- Department of Civil Engineering, Nagoya Institute of Technology (Nitech), Nagoya, 466-8555, Japan
| | - Naoko Yoshida
- Department of Civil Engineering, Nagoya Institute of Technology (Nitech), Nagoya, 466-8555, Japan.
| | - Lingyu Meng
- Department of Civil Engineering, Nagoya Institute of Technology (Nitech), Nagoya, 466-8555, Japan
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10
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Meinel M, Delgado AG, Ilhan ZE, Aguero ML, Aguiar S, Krajmalnik-Brown R, Torres CI. Organic carbon metabolism is a main determinant of hydrogen demand and dynamics in anaerobic soils. CHEMOSPHERE 2022; 303:134877. [PMID: 35577129 DOI: 10.1016/j.chemosphere.2022.134877] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 04/29/2022] [Accepted: 05/04/2022] [Indexed: 06/15/2023]
Abstract
Hydrogen (H2) is a crucial electron donor for many processes in the environment including nitrate-, sulfate- and, iron-reduction, homoacetogenesis, and methanogenesis, and is a major determinant of microbial competition and metabolic pathways in groundwater, sediments, and soils. Despite the importance of H2 for many microbial processes in the environment, the total H2 consuming capacity (or H2 demand) of soils is generally unknown. Using soil microcosms with added H2, the aims of this study were 1) to measure the H2 demand of geochemically diverse soils and 2) to define the processes leading to this demand. Study results documented a large range of H2 demand in soil (0.034-1.2 millielectron equivalents H2 g-1 soil). The measured H2 demand greatly exceeded the theoretical demand predicted based on measured concentrations of common electron acceptors initially present in a library of 15 soils. While methanogenesis accounted for the largest fraction of H2 demand, humic acid reduction and acetogenesis were also significant contributing H2-consuming processes. Much of the H2 demand could be attributed to CO2 produced during incubation from fermentation and/or acetoclastic methanogenesis. The soil initial total organic carbon showed the strongest correlation to H2 demand. Besides external additions, H2 was likely generated or cycled in the microcosms. Apart from fermentative H2 production, carboxylate elongation to produce C4-C7 fatty acids may have accounted for additional H2 production in these soils. Many of these processes, especially the organic carbon contribution is underestimated in microbial models for H2 consumption in natural soil ecosystems or during bioremediation of contaminants in soils.
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Affiliation(s)
- Megan Meinel
- Arizona State University, Biodesign Swette Center for Environmental Biotechnology, 1001 S McAllister Ave, Tempe, AZ, USA; Arizona State University, School of Sustainable Engineering and the Built Environment, 1001 S McAllister Ave, Tempe, AZ, USA; Arizona State University, Engineering Research Center for Bio-mediated and Bio-inspired Geotechnics (CBBG), 1001 S McAllister Ave, Tempe, AZ, USA
| | - Anca G Delgado
- Arizona State University, Biodesign Swette Center for Environmental Biotechnology, 1001 S McAllister Ave, Tempe, AZ, USA; Arizona State University, School of Sustainable Engineering and the Built Environment, 1001 S McAllister Ave, Tempe, AZ, USA; Arizona State University, Engineering Research Center for Bio-mediated and Bio-inspired Geotechnics (CBBG), 1001 S McAllister Ave, Tempe, AZ, USA
| | - Zehra Esra Ilhan
- Arizona State University, Biodesign Swette Center for Environmental Biotechnology, 1001 S McAllister Ave, Tempe, AZ, USA
| | - Marisol Luna Aguero
- Arizona State University, Biodesign Swette Center for Environmental Biotechnology, 1001 S McAllister Ave, Tempe, AZ, USA; Arizona State University, School of Sustainable Engineering and the Built Environment, 1001 S McAllister Ave, Tempe, AZ, USA; Arizona State University, Engineering Research Center for Bio-mediated and Bio-inspired Geotechnics (CBBG), 1001 S McAllister Ave, Tempe, AZ, USA
| | - Samuel Aguiar
- Arizona State University, Biodesign Swette Center for Environmental Biotechnology, 1001 S McAllister Ave, Tempe, AZ, USA; Arizona State University, Engineering Research Center for Bio-mediated and Bio-inspired Geotechnics (CBBG), 1001 S McAllister Ave, Tempe, AZ, USA
| | - Rosa Krajmalnik-Brown
- Arizona State University, Biodesign Swette Center for Environmental Biotechnology, 1001 S McAllister Ave, Tempe, AZ, USA; Arizona State University, School of Sustainable Engineering and the Built Environment, 1001 S McAllister Ave, Tempe, AZ, USA; Arizona State University, Engineering Research Center for Bio-mediated and Bio-inspired Geotechnics (CBBG), 1001 S McAllister Ave, Tempe, AZ, USA; Arizona State University, Biodesign Center for Health Through Microbiomes, 1001 S McAllister Ave, Tempe, AZ, USA.
| | - César I Torres
- Arizona State University, Biodesign Swette Center for Environmental Biotechnology, 1001 S McAllister Ave, Tempe, AZ, USA; Arizona State University, Engineering Research Center for Bio-mediated and Bio-inspired Geotechnics (CBBG), 1001 S McAllister Ave, Tempe, AZ, USA; Arizona State University, School for Engineering of Matter, Transport & Energy, 1001 S McAllister Ave, Tempe, AZ, USA.
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11
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Cheng J, Tang D, Tang Z, Guo J. A novel sulfur-driven autotrophic denitrification coupled with bio-cathode system for bioelectricity generation and groundwater remediation. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2022; 86:979-991. [PMID: 36358041 DOI: 10.2166/wst.2022.216] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
This study explored the feasibility of treating wastewater using sulfur-driven autotrophic denitrification (SAD) coupled with the bio-cathode of microbial fuel cell (MFC), focusing on simultaneous bioelectricity generation, denitrification, and desulphurization. A maximum output voltage of 360 mV was obtained with a power generation cycle of 25 h when simulated wastewater with 100.0 mg/L of each NO3--N and S2--S was employed as the influent in the SAD-BMFC. Compared with solo SAD or MFC, SAD-BMFC obtained a higher NO3--N removal rate (E12 h = 87.7%, E24 h = 100%), and less NO2--N accumulation. S2--S of the influent was almost completely removed, oxidized to S0-S (88.6-90.2 mg/L) and SO42--S (9.8-11.4 mg/L). The reaction system achieved self-balance of acidity-alkalinity (pH 7.05-7.35). The SAD process was the main pathway for NO3--N removal (80.2%) and a smaller proportion of electrons came from the bio-cathode. This study effectively combined SAD with a bio-cathode system for simultaneous energy harvest and bio-enhanced remediation of groundwater contaminated by both NO3--N and S2--S.
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Affiliation(s)
- Jianping Cheng
- School of Mechanical Engineering, Hefei University of Technology, Hefei, Anhui Province 230009, China E-mail:
| | - Dai Tang
- School of Mechanical Engineering, Hefei University of Technology, Hefei, Anhui Province 230009, China E-mail:
| | - Zhiguo Tang
- School of Mechanical Engineering, Hefei University of Technology, Hefei, Anhui Province 230009, China E-mail:
| | - Jin Guo
- School of Environment and Chemical Engineering, Anhui Vocational and Technical College, Hefei, Anhui Province 230011, China
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12
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Chen F, Li Z, Ye Y, Lv M, Liang B, Yuan Y, Cheng HY, Liu Y, He Z, Wang H, Wang Y, Wang A. Coupled sulfur and electrode-driven autotrophic denitrification for significantly enhanced nitrate removal. WATER RESEARCH 2022; 220:118675. [PMID: 35635922 DOI: 10.1016/j.watres.2022.118675] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 05/17/2022] [Accepted: 05/24/2022] [Indexed: 06/15/2023]
Abstract
Elemental sulfur (S0)-based autotrophic denitrification (SAD) has gained intensive attention in the treatment of secondary effluent for its low cost, high efficiency, and good stability. However, in practice, the supplementary addition of limestone is necessary to balance the alkalinity consumption during SAD operation, which increases water hardness and reduces the effective reaction volume. In this study, a coupled sulfur and electrode-driven autotrophic denitrification (SEAD) process was proposed with superior nitrate removal performance, less accumulation of sulfate, and self-balance of acidity-alkalinity capacity by regulating the applied voltage. The dual-channel electron supply from S0 and electrodes made the nitrate removal rate constant k in the SEAD process 3.7-5.1 and 1.4-3.5 times higher than that of the single electrode- and sulfur-driven systems, respectively. The S° contributed to 75.3%-83.1% of nitrate removal and the sulfate yield during SEAD (5.67-6.26 mg SO42-/mg NO3--N) was decreased by 17%-25% compared with SAD. The S0 particle and electrode both as active bio-carriers constructed collaborative denitrification communities and functional genes. Pseudomonas, Ralstonia and Brevundimonas were the dominant denitrifying genera in S0 particle biofilm, while Pseudomonas, Chryseobacterium, Pantoea and Comamonas became dominant denitrifying genera in the cathode biofilm. The narG/Z/H/Y/I/V, nxrA/B, napA/B, nirS/K, norB/C and nosZ were potential functional genes for efficient nitrate reduction during the SEAD process. Metagenomic sequencing indicated that S0 as an electron donor has greater potential for complete denitrification than the electrode. These findings revealed the potential of SEAD for acting as a highly efficient post denitrification process.
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Affiliation(s)
- Fan Chen
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, P. R. China; School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, 710129, P. R. China
| | - Zhiling Li
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, P. R. China
| | - Yin Ye
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, 710129, P. R. China
| | - Miao Lv
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, P. R. China
| | - Bin Liang
- State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen, 518055, P.R. China
| | - Ye Yuan
- School of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng, 224051, P.R. China
| | - Hao-Yi Cheng
- State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen, 518055, P.R. China
| | - Yang Liu
- College of Eco-Environmental Engineering, Qinghai University, Xining, 810016, P.R. China
| | - Zhangwei He
- School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, P.R. China
| | - Hongcheng Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen, 518055, P.R. China
| | - Yuheng Wang
- School of Ecology and Environment, Northwestern Polytechnical University, Xi'an, 710129, P. R. China
| | - Aijie Wang
- State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, P. R. China; State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen, 518055, P.R. China.
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13
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Robles A, Yellowman TL, Joshi S, Mohana Rangan S, Delgado AG. Microbial Chain Elongation and Subsequent Fermentation of Elongated Carboxylates as H 2-Producing Processes for Sustained Reductive Dechlorination of Chlorinated Ethenes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:10398-10410. [PMID: 34283573 DOI: 10.1021/acs.est.1c01319] [Citation(s) in RCA: 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.
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Affiliation(s)
- Aide Robles
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, 1001 S. McAllister Ave., Tempe, Arizona 85287, United States
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Engineering Research Center for Bio-mediated and Bio-inspired Geotechnics, Arizona State University, Tempe, Arizona 85281, United States
| | - Theodora L Yellowman
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, 1001 S. McAllister Ave., Tempe, Arizona 85287, United States
- Engineering Research Center for Bio-mediated and Bio-inspired Geotechnics, Arizona State University, Tempe, Arizona 85281, United States
| | - Sayalee Joshi
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, 1001 S. McAllister Ave., Tempe, Arizona 85287, United States
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Engineering Research Center for Bio-mediated and Bio-inspired Geotechnics, Arizona State University, Tempe, Arizona 85281, United States
| | - Srivatsan Mohana Rangan
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, 1001 S. McAllister Ave., Tempe, Arizona 85287, United States
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Engineering Research Center for Bio-mediated and Bio-inspired Geotechnics, Arizona State University, Tempe, Arizona 85281, United States
| | - Anca G Delgado
- Biodesign Swette Center for Environmental Biotechnology, Arizona State University, 1001 S. McAllister Ave., Tempe, Arizona 85287, United States
- School of Sustainable Engineering and the Built Environment, Arizona State University, Tempe, Arizona 85281, United States
- Engineering Research Center for Bio-mediated and Bio-inspired Geotechnics, Arizona State University, Tempe, Arizona 85281, United States
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Kandris K, Pantazidou M, Mamais D. Model-based evidence for the relevance of microbial community variability to the efficiency of the anaerobic reductive dechlorination of TCE. JOURNAL OF CONTAMINANT HYDROLOGY 2021; 241:103834. [PMID: 34044306 DOI: 10.1016/j.jconhyd.2021.103834] [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: 10/27/2020] [Revised: 03/18/2021] [Accepted: 05/17/2021] [Indexed: 06/12/2023]
Abstract
The composition of mixed dechlorinating communities varies considerably in field and laboratory conditions. Dechlorinators thrive alongside with distinctive populations that help or hinder dechlorination. The variability of the composition of dechlorinating communities inevitably precludes a firm consensus regarding the optimal strategies for biostimulation. This lack of consensus motivated a model-based approach for the investigation of how the variability of the composition of a microbial community impacts the electron donor supply strategies for accelerating chloroethene removal. To this end, a kinetic model accounting for dechlorination in conjunction with cooperative and competing processes was developed. Model parameters were estimated using a multi-experiment, multi-start algorithm and data from research previously performed with two generations of a methane-producing, Dehalococcoides mccartyi-dominated consortium. The two generations of the consortium functioned comparably under maintenance conditions but performed divergently under high electron donor surpluses. The multi-experiment, multi-start algorithm overcame the hurdles of poor parameter identifiability and offered a probable cause for the different behaviors exhibited by each of the two generations of the chloroethene-degrading consortium: modest differences in the make-up of non-dechlorinators, which were minority populations, significantly influenced the fate of the offered electron donor.
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Affiliation(s)
- Kyriakos Kandris
- Department of Geotechnical Engineering, School of Civil Engineering, National Technical University of Athens, Athens, Greece.
| | - Marina Pantazidou
- Department of Geotechnical Engineering, School of Civil Engineering, National Technical University of Athens, Athens, Greece.
| | - Daniel Mamais
- Department of Water Resources and Environmental Engineering, School of Civil Engineering, National Technical University of Athens, Athens, Greece.
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15
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Haluska AA, Finneran KT. Increasing electron donor concentration does not accelerate complete microbial reductive dechlorination in contaminated sediment with native organic carbon. Biodegradation 2021; 32:577-593. [PMID: 34081242 DOI: 10.1007/s10532-021-09953-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Accepted: 05/22/2021] [Indexed: 11/26/2022]
Abstract
Experiments with Fe(III)-rich, chloroethene-contaminated sediment demonstrated that trichloroethylene (TCE) and vinyl chloride (VC) were completely reduced to ethene regardless of whether electron donor(s) were added at 1 × stoichiometry or 10 × stoichiometry relative to all-electron acceptors. Unamended controls uniformly reduced TCE to ethene with a mean time to complete dechlorination (operationally defined as the presence of stoichiometric ethene production) of 79 days. Adding 1 × and 10 × acetate hindered the rate and extent of TCE and VC reduction relative to unamended controls, with several only partially reduced when the experiments were terminated. Adding high molecular mass (soybean oil derivative) substrates did not increase microbial reductive dechlorination relative to unamended incubations, and in many cases, hindered microbial dechlorination in favor of methanogenesis. The mean time to complete dechlorination was comparable between low (× 1) and high (× 10) electron donor concentration for all lipid-based electron donors tested. Those tested included Newman Zone® Standard without sodium lactate (96 vs. 75 days, respectively), CAP 18 ME (85 vs. 94 days, respectively), EOS 598B42 (68 vs. 72 days, respectively), and acetate (134 vs. 125 days, respectively). These data suggest that the addition of an electron donor does not always increase the rate and extent of reductive dechlorination but will increase costs. In particular, increasing the concentration of electron donors higher than the stoichiometric demand only decreased complete microbial reductive dechlorination, which is the opposite of most standard "more time and more electrons" approaches. These data argue that site-specific electron donor demands must be evaluated, and in some cases, a monitored natural attenuation (MNA) approach is most favorable.
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Affiliation(s)
- Alexander Arthur Haluska
- Environmental Engineering and Earth Sciences, Clemson University, 312 Biosystems Research Complex, 105 Collings Street, Clemson, SC, 29634, USA
- Center for Applied Geoscience, Geological Institute, University of Tϋbingen, Hölderlinstrße 12, 72070, Tübingen, Germany
| | - Kevin T Finneran
- Environmental Engineering and Earth Sciences, Clemson University, 312 Biosystems Research Complex, 105 Collings Street, Clemson, SC, 29634, USA.
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16
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Chen G, Jiang N, Villalobos Solis MI, Kara Murdoch F, Murdoch RW, Xie Y, Swift CM, Hettich RL, Löffler FE. Anaerobic Microbial Metabolism of Dichloroacetate. mBio 2021; 12:e00537-21. [PMID: 33906923 PMCID: PMC8092247 DOI: 10.1128/mbio.00537-21] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Accepted: 03/17/2021] [Indexed: 12/23/2022] Open
Abstract
Dichloroacetate (DCA) commonly occurs in the environment due to natural production and anthropogenic releases, but its fate under anoxic conditions is uncertain. Mixed culture RM comprising "Candidatus Dichloromethanomonas elyunquensis" strain RM utilizes DCA as an energy source, and the transient formation of formate, H2, and carbon monoxide (CO) was observed during growth. Only about half of the DCA was recovered as acetate, suggesting a fermentative catabolic route rather than a reductive dechlorination pathway. Sequencing of 16S rRNA gene amplicons and 16S rRNA gene-targeted quantitative real-time PCR (qPCR) implicated "Candidatus Dichloromethanomonas elyunquensis" strain RM in DCA degradation. An (S)-2-haloacid dehalogenase (HAD) encoded on the genome of strain RM was heterologously expressed, and the purified HAD demonstrated the cofactor-independent stoichiometric conversion of DCA to glyoxylate at a rate of 90 ± 4.6 nkat mg-1 protein. Differential protein expression analysis identified enzymes catalyzing the conversion of DCA to acetyl coenzyme A (acetyl-CoA) via glyoxylate as well as enzymes of the Wood-Ljungdahl pathway. Glyoxylate carboligase, which catalyzes the condensation of two molecules of glyoxylate to form tartronate semialdehyde, was highly abundant in DCA-grown cells. The physiological, biochemical, and proteogenomic data demonstrate the involvement of an HAD and the Wood-Ljungdahl pathway in the anaerobic fermentation of DCA, which has implications for DCA turnover in natural and engineered environments, as well as the metabolism of the cancer drug DCA by gut microbiota.IMPORTANCE Dichloroacetate (DCA) is ubiquitous in the environment due to natural formation via biological and abiotic chlorination processes and the turnover of chlorinated organic materials (e.g., humic substances). Additional sources include DCA usage as a chemical feedstock and cancer drug and its unintentional formation during drinking water disinfection by chlorination. Despite the ubiquitous presence of DCA, its fate under anoxic conditions has remained obscure. We discovered an anaerobic bacterium capable of metabolizing DCA, identified the enzyme responsible for DCA dehalogenation, and elucidated a novel DCA fermentation pathway. The findings have implications for the turnover of DCA and the carbon and electron flow in electron acceptor-depleted environments and the human gastrointestinal tract.
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Affiliation(s)
- Gao Chen
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, USA
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee, USA
| | - Nannan Jiang
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, USA
- Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, Tennessee, USA
- University of Tennessee and Oak Ridge National Laboratory (UT-ORNL) Joint Institute for Biological Sciences (JIBS), Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | | | - Fadime Kara Murdoch
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, USA
- University of Tennessee and Oak Ridge National Laboratory (UT-ORNL) Joint Institute for Biological Sciences (JIBS), Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Robert Waller Murdoch
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, USA
| | - Yongchao Xie
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, USA
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee, USA
| | - Cynthia M Swift
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, USA
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
| | - Robert L Hettich
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Frank E Löffler
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, USA
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee, USA
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
- Department of Biosystems Engineering & Soil Science, University of Tennessee, Knoxville, Tennessee, USA
- Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, Tennessee, USA
- Genome Science and Technology, University of Tennessee, Knoxville, Tennessee, USA
- University of Tennessee and Oak Ridge National Laboratory (UT-ORNL) Joint Institute for Biological Sciences (JIBS), Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
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17
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Li J, Hu A, Bai S, Yang X, Sun Q, Liao X, Yu CP. Characterization and Performance of Lactate-Feeding Consortia for Reductive Dechlorination of Trichloroethene. Microorganisms 2021; 9:microorganisms9040751. [PMID: 33918519 PMCID: PMC8065584 DOI: 10.3390/microorganisms9040751] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 03/26/2021] [Accepted: 03/30/2021] [Indexed: 11/16/2022] Open
Abstract
Understanding the underlying mechanism that drives the microbial community mediated by substrates is crucial to enhance the biostimulation in trichloroethene (TCE)-contaminated sites. Here, we investigated the performance of stable TCE-dechlorinating consortia by monitoring the variations in TCE-related metabolites and explored their underlying assembly mechanisms using 16S rDNA amplicon sequencing and bioinformatics analyses. The monitoring results indicated that three stable TCE-dechlorinating consortia were successfully enriched by lactate-containing anaerobic media. The statistical analysis results demonstrated that the microbial communities of the enrichment cultures changed along with time and were distinguished by their sample sources. The deterministic and stochastic processes were simultaneously responsible for shaping the TCE-dechlorinating community assembly. The indicator patterns shifted with the exhaustion of the carbon source and the pollutants, and the tceA-carrying Dehalococcoides, as an indicator for the final stage samples, responded positively to TCE removal during the incubation period. Pseudomonas, Desulforhabdus, Desulfovibrio and Methanofollis were identified as keystone populations in the TCE-dechlorinating process by co-occurrence network analysis. The results of this study indicate that lactate can be an effective substrate for stimulated bioremediation of TCE-contaminated sites, and the reduction of the stochastic forces or enhancement of the deterministic interventions may promote more effective biostimulation.
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Affiliation(s)
- Jiangwei Li
- CAS Key Laboratory of Urban Pollutant Conversion, Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; (J.L.); (A.H.); (X.Y.); (Q.S.); (X.L.)
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Anyi Hu
- CAS Key Laboratory of Urban Pollutant Conversion, Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; (J.L.); (A.H.); (X.Y.); (Q.S.); (X.L.)
| | - Shijie Bai
- Institute of Deep Sea Science and Engineering, Chinese Academic of Sciences, Sanya 572000, China;
| | - Xiaoyong Yang
- CAS Key Laboratory of Urban Pollutant Conversion, Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; (J.L.); (A.H.); (X.Y.); (Q.S.); (X.L.)
| | - Qian Sun
- CAS Key Laboratory of Urban Pollutant Conversion, Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; (J.L.); (A.H.); (X.Y.); (Q.S.); (X.L.)
| | - Xu Liao
- CAS Key Laboratory of Urban Pollutant Conversion, Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; (J.L.); (A.H.); (X.Y.); (Q.S.); (X.L.)
| | - Chang-Ping Yu
- CAS Key Laboratory of Urban Pollutant Conversion, Fujian Key Laboratory of Watershed Ecology, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; (J.L.); (A.H.); (X.Y.); (Q.S.); (X.L.)
- Water Innovation, Low Carbon and Environmental Sustainability Research Center, National Taiwan University, Taipei 10617, Taiwan
- Correspondence:
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18
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Organohalide-Respiring Bacteria at the Heart of Anaerobic Metabolism in Arctic Wet Tundra Soils. Appl Environ Microbiol 2021; 87:AEM.01643-20. [PMID: 33187999 DOI: 10.1128/aem.01643-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 11/10/2020] [Indexed: 11/20/2022] Open
Abstract
Recent work revealed an active biological chlorine cycle in coastal Arctic tundra of northern Alaska. This raised the question of whether chlorine cycling was restricted to coastal areas or if these processes extended to inland tundra. The anaerobic process of organohalide respiration, carried out by specialized bacteria like Dehalococcoides, consumes hydrogen gas and acetate using halogenated organic compounds as terminal electron acceptors, potentially competing with methanogens that produce the greenhouse gas methane. We measured microbial community composition and soil chemistry along an ∼262-km coastal-inland transect to test for the potential of organohalide respiration across the Arctic Coastal Plain and studied the microbial community associated with Dehalococcoides to explore the ecology of this group and its potential to impact C cycling in the Arctic. Concentrations of brominated organic compounds declined sharply with distance from the coast, but the decrease in organic chlorine pools was more subtle. The relative abundances of Dehalococcoides were similar across the transect, except for being lower at the most inland site. Dehalococcoides correlated with other strictly anaerobic genera, plus some facultative ones, that had the genetic potential to provide essential resources (hydrogen, acetate, corrinoids, or organic chlorine). This community included iron reducers, sulfate reducers, syntrophic bacteria, acetogens, and methanogens, some of which might also compete with Dehalococcoides for hydrogen and acetate. Throughout the Arctic Coastal Plain, Dehalococcoides is associated with the dominant anaerobes that control fluxes of hydrogen, acetate, methane, and carbon dioxide. Depending on seasonal electron acceptor availability, organohalide-respiring bacteria could impact carbon cycling in Arctic wet tundra soils.IMPORTANCE Once considered relevant only in contaminated sites, it is now recognized that biological chlorine cycling is widespread in natural environments. However, linkages between chlorine cycling and other ecosystem processes are not well established. Species in the genus Dehalococcoides are highly specialized, using hydrogen, acetate, vitamin B12-like compounds, and organic chlorine produced by the surrounding community. We studied which neighbors might produce these essential resources for Dehalococcoides species. We found that Dehalococcoides species are ubiquitous across the Arctic Coastal Plain and are closely associated with a network of microbes that produce or consume hydrogen or acetate, including the most abundant anaerobic bacteria and methanogenic archaea. We also found organic chlorine and microbes that can produce these compounds throughout the study area. Therefore, Dehalococcoides could control the balance between carbon dioxide and methane (a more potent greenhouse gas) when suitable organic chlorine compounds are available to drive hydrogen and acetate uptake.
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19
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Wang X, Xin J, Yuan M, Zhao F. Electron competition and electron selectivity in abiotic, biotic, and coupled systems for dechlorinating chlorinated aliphatic hydrocarbons in groundwater: A review. WATER RESEARCH 2020; 183:116060. [PMID: 32750534 DOI: 10.1016/j.watres.2020.116060] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2019] [Revised: 06/01/2020] [Accepted: 06/13/2020] [Indexed: 06/11/2023]
Abstract
Chlorinated aliphatic hydrocarbons (CAHs) have been frequently detected in aquifers in recent years. Owing to the bioaccumulation and toxicity of CAHs, it is essential to explore high-efficiency technologies for their complete dechlorination in groundwater. At present, the most widely used abiotic and biotic remediation technologies are based on zero-valent iron (ZVI) and functional anaerobic bacteria (FAB), respectively. However, the main obstacles to the full potential of both technologies in the field include their lowered efficiencies and increased economic costs due to the co-existence of a variety of natural electron acceptors in the environment, such as dissolved oxygen (DO), nitrate (NO3-), sulfate (SO42-), ferric iron (Fe (III)), bicarbonate (HCO3-), and even water, which compete for electrons with the target contaminants. Therefore, a clear understanding of the mechanisms governing electron competition and electron selectivity is significant for the accurate evaluation of the effectiveness of both technologies under natural hydrochemical conditions. We collected data from both abiotic and biotic CAH-remediation systems, summarized the dechlorination and undesired reactions in groundwater, discussed the characterization methods and general principles of electron competition, and described strategies to improve electron selectivity in both systems. Furthermore, we reviewed the emerging ZVI-FAB coupled system, which integrates abiotic and biotic processes to enhance dechlorination performance and electron utilization efficiency. Lastly, we propose future research needs to quantitatively understand the electron competition in abiotic, biotic, and coupled systems in more detail and to promote improved electron selectivity in groundwater remediation.
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Affiliation(s)
- Xiaohui Wang
- Key Lab of Marine Environmental Science and Ecology, Ministry of Education Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Jia Xin
- Key Lab of Marine Environmental Science and Ecology, Ministry of Education Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China.
| | - Mengjiao Yuan
- Key Lab of Marine Environmental Science and Ecology, Ministry of Education Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
| | - Fang Zhao
- Key Lab of Marine Environmental Science and Ecology, Ministry of Education Shandong Provincial Key Laboratory of Marine Environment and Geological Engineering College of Environmental Science and Engineering, Ocean University of China, Qingdao, 266100, China
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Abstract
The class Dehalococcoidia within the Chloroflexi phylum comprises the obligate organohalide-respiring genera Dehalococcoides, Dehalogenimonas, and “Candidatus Dehalobium.” Knowledge of the unique ecophysiology and biochemistry of Dehalococcoidia has been largely derived from studies with enrichment cultures and isolates from sites impacted with chlorinated pollutants; however, culture-independent surveys found Dehalococcoidia sequences in marine, freshwater, and terrestrial biomes considered to be pristine (i. The class Dehalococcoidia within the Chloroflexi phylum comprises the obligate organohalide-respiring genera Dehalococcoides, Dehalogenimonas, and “Candidatus Dehalobium.” Knowledge of the unique ecophysiology and biochemistry of Dehalococcoidia has been largely derived from studies with enrichment cultures and isolates from sites impacted with chlorinated pollutants; however, culture-independent surveys found Dehalococcoidia sequences in marine, freshwater, and terrestrial biomes considered to be pristine (i.e., not impacted with organohalogens of anthropogenic origin). The broad environmental distribution of Dehalococcoidia, as well as other organohalide-respiring bacteria, supports the concept of active halogen cycling and the natural formation of organohalogens in various ecosystems. Dechlorination reduces recalcitrance and renders organics susceptible to metabolic oxidation by diverse microbial taxa. During reductive dechlorination, hydrogenotrophic organohalide-respiring bacteria, in particular Dehalococcoidia, can consume hydrogen to low consumption threshold concentrations (<0.3 nM) and enable syntrophic oxidation processes. These functional attributes and the broad distribution imply that Dehalococcoidia play relevant roles in carbon cycling in anoxic ecosystems.
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21
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Lu Q, Zou X, Liu J, Liang Z, Shim H, Qiu R, Wang S. Inhibitory effects of metal ions on reductive dechlorination of polychlorinated biphenyls and perchloroethene in distinct organohalide-respiring bacteria. ENVIRONMENT INTERNATIONAL 2020; 135:105373. [PMID: 31841802 DOI: 10.1016/j.envint.2019.105373] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 11/27/2019] [Accepted: 11/28/2019] [Indexed: 06/10/2023]
Abstract
Bioremediation of sites co-contaminated with organohalides and metal pollutants may have unsatisfactory performance, since metal ions can potentially inhibit organohalide respiration. To understand the detailed impact of metals on organohalide respiration, we tested the effects of four metal ions (i.e., Cu2+, Cd2+, Cr3+ and Pb2+), as well as their mixtures, on reductive dechlorination of perchloroethene (PCE) and polychlorinated biphenyls (PCBs) in three different cultures, including a pure culture of Dehalococcoides mccartyi CG1, a Dehalococcoides-containing microcosm and a Dehalococcoides-Geobacter coculture. Results showed that the inhibitive impact on organohalide respiration depended on both the type and concentration of metal ions. Interestingly, the metal ions might indirectly inhibit organohalide respiration through affecting non-dechlorinating populations in the Dehalococcoides-containing microcosm. Nonetheless, compared to the CG1 pure culture, the Dehalococcoides-containing microcosm had higher tolerance to the individual metal ions. In addition, no synergistic inhibition was observed for reductive dechlorination of PCE and PCBs in cultures amended with metal ion mixtures. These results provide insights into the impact of metal ions on organohalide respiration, which may be helpful for future in situ bioremediation of organohalide-metal co-contaminated sites.
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Affiliation(s)
- Qihong Lu
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China; Environmental Microbiome Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou 510275, China
| | - Xueqi Zou
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
| | - Jinting Liu
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
| | - Zhiwei Liang
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
| | - Hojae Shim
- Department of Civil and Environmental Engineering, Faculty of Science and Technology, University of Macau, 999078, Macau
| | - Rongliang Qiu
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou 510275, China.
| | - Shanquan Wang
- School of Environmental Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China; Environmental Microbiome Research Center, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Sun Yat-Sen University, Guangzhou 510275, China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Guangzhou 510275, China.
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22
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Mineralization versus fermentation: evidence for two distinct anaerobic bacterial degradation pathways for dichloromethane. ISME JOURNAL 2020; 14:959-970. [PMID: 31907367 DOI: 10.1038/s41396-019-0579-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 12/11/2019] [Accepted: 12/17/2019] [Indexed: 01/03/2023]
Abstract
Dichloromethane (DCM) is an anthropogenic pollutant with ozone destruction potential that is also formed naturally. Under anoxic conditions, fermentation of DCM to acetate and formate has been reported in axenic culture Dehalobacterium formicoaceticum, and to acetate, H2 and CO2 in mixed culture RM, which harbors the DCM degrader 'Candidatus Dichloromethanomonas elyunquensis'. RM cultures produced 28.1 ± 2.3 μmol of acetate from 155.6 ± 9.3 μmol DCM, far less than the one third (i.e., about 51.9 µmol) predicted based on the assumed fermentation model, and observed in cultures of Dehalobacterium formicoaceticum. Temporal metabolite analyses using gas chromatography-mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) spectroscopy revealed that no 13C-labeled acetate was formed in 13C-DCM-grown RM cultures, indicating acetate was not a direct product of DCM metabolism. The data were reconciled with DCM mineralization and H2 consumption via CO2 reduction to acetate and methane by homoacetogenic and methanogenic partner populations, respectively. In contrast, Dehalobacterium formicoaceticum produced 13C-labeled acetate and formate from 13C-DCM, consistent with a fermentation pathway. Free energy change calculations predicted that organisms with the mineralization pathway are the dominant DCM consumers in environments with H2 <100 ppmv. These findings have implications for carbon and electron flow in environments where DCM is introduced through natural production processes or anthropogenic activities.
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Al-Fathi H, Koch M, Lorenz WG, Lechner U. Anaerobic degradation of 2,4,5-trichlorophenoxyacetic acid by enrichment cultures from freshwater sediments. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:34459-34467. [PMID: 31642015 DOI: 10.1007/s11356-019-06584-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Accepted: 09/23/2019] [Indexed: 06/10/2023]
Abstract
The anaerobic biodegradation of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) was investigated using enrichment cultures from freshwater sediments at two different sites in the region of Halle, central Germany. 2,4,5-T and different organic acids or hydrogen were added as possible electron acceptor and electron donors, respectively. The primary enrichment cultures from Saale river sediment completely degraded 2,4,5-T to 3-chlorophenol (3-CP) (major product) and 3,4-dichlorophenol (3,4-DCP) during a 28-day incubation period. Subcultures showed ether cleavage of 2,4,5-T to 2,4,5-trichlorophenol and its stoichiometric dechlorination to 3-CP only in the presence of butyrate. In contrast, the primary enrichment culture from sediment of Posthorn pond dechlorinated 2,4,5-T to 2,5-dichlorophenoxyacetic acid (2,5-D), which, in the presence of butyrate, was degraded further to products such as 3,4-DCP, 2,5-DCP, and 3CP, indicating ether cleaving activities and subsequent dechlorination steps. Experiments with pure cultures of Dehalococcoides mccartyi and Desulfitobacterium hafniense demonstrated their specific dechlorination steps within the overall 2,4,5-T degradation pathways. The results indicate that the route and efficiency of anaerobic 2,4,5-T degradation in the environment depend heavily on the microorganisms present and the availability of slowly fermentable organic compounds.
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Affiliation(s)
- Hassan Al-Fathi
- Institute of Biology/Microbiology, Martin-Luther University Halle-Wittenberg, Halle, Germany
- Department Environmental Microbiology, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Mandy Koch
- Institute of Chemistry/Food and Environmental Chemistry, Martin-Luther University Halle-Wittenberg, Halle, Germany
| | - Wilhelm G Lorenz
- Institute of Chemistry/Food and Environmental Chemistry, Martin-Luther University Halle-Wittenberg, Halle, Germany
| | - Ute Lechner
- Institute of Biology/Microbiology, Martin-Luther University Halle-Wittenberg, Halle, Germany.
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24
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Mao X, Stenuit B, Tremblay J, Yu K, Tringe SG, Alvarez-Cohen L. Structural dynamics and transcriptomic analysis of Dehalococcoides mccartyi within a TCE-Dechlorinating community in a completely mixed flow reactor. WATER RESEARCH 2019; 158:146-156. [PMID: 31035191 PMCID: PMC7053656 DOI: 10.1016/j.watres.2019.04.038] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 04/10/2019] [Accepted: 04/15/2019] [Indexed: 05/13/2023]
Abstract
A trichloroethene (TCE)-dechlorinating community (CANAS) maintained in a completely mixed flow reactor was established from a semi-batch enrichment culture (ANAS) and was monitored for 400 days at a low solids retention time (SRT) under electron acceptor limitation. Around 85% of TCE supplied to CANAS (0.13 mmol d-1) was converted to ethene at a rate of 0.1 mmol d-1, with detection of low production rates of vinyl chloride (6.8 × 10-3 mmol d-1) and cis-dichloroethene (2.3 × 10-3 mmol d-1). Two distinct Dehalococcoides mccartyi strains (ANAS1 and ANAS2) were stably maintained at 6.2 ± 2.8 × 108 cells mL-1 and 5.8 ± 1.2 × 108 cells mL-1, respectively. Electron balance analysis showed 107% electron recovery, in which 6.1% were involved in dechlorination. 16 S rRNA amplicon sequencing revealed a structural regime shift between ANAS and CANAS while maintaining robust TCE dechlorination due to similar relative abundances of D. mccartyi and functional redundancy among each functional guild supporting D. mccartyi activity. D. mccartyi transcriptomic analysis identified the genes encoding for ribosomal RNA and the reductive dehalogenases tceA and vcrA as the most expressed genes in CANAS, while hup and vhu were the most critical hydrogenases utilized by D. mccartyi in the community.
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Affiliation(s)
- Xinwei Mao
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA, 94720-1710, USA
| | - Benoit Stenuit
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA, 94720-1710, USA
| | | | - Ke Yu
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA, 94720-1710, USA
| | - Susannah G Tringe
- DOE Joint Genome Institute, Walnut Creek, CA, USA; Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Lisa Alvarez-Cohen
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA, 94720-1710, USA; Earth and Environmental Sciences Area, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
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25
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Berns EC, Sanford RA, Valocchi AJ, Strathmann TJ, Schaefer CE, Werth CJ. Contributions of biotic and abiotic pathways to anaerobic trichloroethene transformation in low permeability source zones. JOURNAL OF CONTAMINANT HYDROLOGY 2019; 224:103480. [PMID: 31006532 DOI: 10.1016/j.jconhyd.2019.04.003] [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: 11/08/2018] [Revised: 03/12/2019] [Accepted: 04/09/2019] [Indexed: 06/09/2023]
Abstract
Low permeability source zones sustain long-term trichloroethene (TCE) groundwater contamination. In anaerobic environments, TCE is transformed by both biological reductive dechlorination and abiotic reactions with reactive minerals. Little is known about the relative contribution of these two pathways as TCE diffuses from low permeability zones (LPZs) into high permeability zones (HPZs). This study combines a flow cell experiment, batch experiments, and a diffusion-reaction model to evaluate the contributions of biotic and abiotic TCE transformation in LPZs. Natural clay (LPZ) and sand (HPZ) from a former Air Force base were used in all experiments. In batch, the LPZ material transformed TCE and cis-1,2-dichloroethene (cis-DCE) to acetylene with pseudo first-order rate constants of 8.57 × 10-6 day-1 and 1.02 × 10-6 day-1, respectively. Biotic and abiotic pathways were then evaluated together in a bench-scale flow cell (16.5 cm × 2 cm × 16.5 cm) that contained a LPZ layer, with a source of TCE at the base, overlain by a HPZ continuously purged with lactate-amended groundwater. Diffusion controlled mass transfer in the LPZ, while advection controlled migration in the HPZ. The mass discharge rate of TCE and its biotic (cis-DCE and vinyl chloride) and abiotic (acetylene) transformation products were measured over 180 days in the flow cell effluent. Depth profiles of these compounds through the LPZ were determined after terminating the experiment. A one-dimensional diffusion-reaction model was used to interpret the effluent and depth profile data and constrain reaction parameters. Abiotic transformation rate constants for TCE to acetylene, normalized to in situ solids loading, were approximately 13 times greater in batch than in the flow cell. Slower transformation rates in the flow cell indicate elevated TCE concentration and/or further degradation of acetylene to other reduced gas compounds in the flow cell LPZ (thereby partially masking TCE abiotic transformation). Biotic and abiotic parameters used to interpret the flow cell data were then used to simulate a field site with a 300 cm thick LPZ. Abiotic processes contributed to a 2% reduction in TCE flux after 730 days. When abiotic rate constants were changed to that observed in batch, or to rate constants previously reported for a pyrite rich mudstone, the TCE flux reduction was 21% and 53%, respectively, after 730 days. Though biotic processes dominated TCE transformation in the flow cell experiment, the simulations indicate that abiotic processes have potential to significantly contribute to TCE attenuation in electron donor limited environments provided suitable reactive minerals are present.
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Affiliation(s)
- Erin C Berns
- The University of Texas at Austin, Department of Civil, Architectural, and Environmental Engineering, 301 E. Dean Keeton St., Stop C1786, Austin, TX 78712, USA
| | - Robert A Sanford
- University of Illinois at Urbana-Champaign, Department of Geology, 1301 West Green St., Urbana, IL 61801, USA
| | - Albert J Valocchi
- University of Illinois at Urbana-Champaign, Department of Civil and Environmental Engineering, 205 North Mathews Ave., Urbana, IL 61801, USA
| | - Timothy J Strathmann
- Colorado School of Mines, Department of Civil and Environmental Engineering, 1500 Illinois St., Golden, CO 80401, USA
| | | | - Charles J Werth
- The University of Texas at Austin, Department of Civil, Architectural, and Environmental Engineering, 301 E. Dean Keeton St., Stop C1786, Austin, TX 78712, USA.
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26
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Role of hydrogen (H 2) mass transfer in microbiological H 2-threshold studies. Biodegradation 2019; 30:113-125. [PMID: 30788623 DOI: 10.1007/s10532-019-09870-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 02/14/2019] [Indexed: 10/27/2022]
Abstract
Gas-to-liquid mass transfer of hydrogen (H2) was investigated in a gas-liquid reactor with a continuous gas phase, a batch liquid phase, and liquid mixing regimes relevant to assessing kinetics of microbial H2 consumption. H2 transfer was quantified in real-time with a H2 microsensor for no mixing, moderate mixing [100 rotations per minute (rpm)], and rapid mixing (200 rpm). The experimental results were simulated by mathematical models to find best-fit values of volumetric mass transfer coefficients-kLa-for H2, which were 1.6/day for no mixing, 7/day for 100 rpm, and 30/day for 200 rpm. Microbiological H2-consumption experiments were conducted with Methanobacterium bryantii M.o.H. to assess effects of H2 mass transfer on microbiological H2-threshold studies. The results illustrate that slow mixing reduced the gas-to-liquid H2 transfer rate, which fell behind the rate of microbiological H2 consumption in the liquid phase. As a result, the liquid-phase H2 concentration remained much lower than the liquid-phase H2 concentration that would be in equilibrium with the gas-phase H2 concentration. Direct measurements of the liquid-phase H2 concentration by an in situ probe demonstrated the problems associated with slow H2 transfer in past H2 threshold studies. The findings indicate that some of the previously reported H2-thresholds most likely were over-estimates due to slow gas-to-liquid H2 transfer. Essential requirements to conduct microbiological H2 threshold experiments are to have vigorous mixing, large gas-to-liquid volume, large interfacial area, and low initial biomass concentration.
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27
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Gregory SP, Barnett MJ, Field LP, Milodowski AE. Subsurface Microbial Hydrogen Cycling: Natural Occurrence and Implications for Industry. Microorganisms 2019; 7:E53. [PMID: 30769950 PMCID: PMC6407114 DOI: 10.3390/microorganisms7020053] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 02/01/2019] [Accepted: 02/03/2019] [Indexed: 12/21/2022] Open
Abstract
Hydrogen is a key energy source for subsurface microbial processes, particularly in subsurface environments with limited alternative electron donors, and environments that are not well connected to the surface. In addition to consumption of hydrogen, microbial processes such as fermentation and nitrogen fixation produce hydrogen. Hydrogen is also produced by a number of abiotic processes including radiolysis, serpentinization, graphitization, and cataclasis of silicate minerals. Both biotic and abiotically generated hydrogen may become available for consumption by microorganisms, but biotic production and consumption are usually tightly coupled. Understanding the microbiology of hydrogen cycling is relevant to subsurface engineered environments where hydrogen-cycling microorganisms are implicated in gas consumption and production and corrosion in a number of industries including carbon capture and storage, energy gas storage, and radioactive waste disposal. The same hydrogen-cycling microorganisms and processes are important in natural sites with elevated hydrogen and can provide insights into early life on Earth and life on other planets. This review draws together what is known about microbiology in natural environments with elevated hydrogen, and highlights where similar microbial populations could be of relevance to subsurface industry.
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Affiliation(s)
- Simon P Gregory
- British Geological Survey, Environmental Science Centre, Keyworth, Nottingham NG12 5GG, UK.
| | - Megan J Barnett
- British Geological Survey, Environmental Science Centre, Keyworth, Nottingham NG12 5GG, UK.
| | - Lorraine P Field
- British Geological Survey, Environmental Science Centre, Keyworth, Nottingham NG12 5GG, UK.
| | - Antoni E Milodowski
- British Geological Survey, Environmental Science Centre, Keyworth, Nottingham NG12 5GG, UK.
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Wan J, Chen C, Chen J, Miao Q, Liu Y, Ye J, Chen K, Jin Y, Tang X, Shen C. Acceleration of perchloroethylene dechlorination by extracellular secretions from Microbacterium in a mixed culture containing Desulfitobacterium. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 245:651-657. [PMID: 30481679 DOI: 10.1016/j.envpol.2018.10.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 09/23/2018] [Accepted: 10/01/2018] [Indexed: 06/09/2023]
Abstract
The study was conducted to demonstrate the influence of extracellular secretions from Microbacterium on the reductive dechlorination of tetrachloroethene (PCE). A series of mixed cultures were established from a paddy soil sample. In the mixed cultures amended with extracellular secretions from Microbacterium, PCE was rapidly and completely converted into cis-1,2-dichloroethene (cis-DCE) and trans-1,2-dichloroethene (trans-DCE) within 40 days. The unamended mixed cultures showed weak signs of dechlorination after a pronounced lag phase, and trichloroethene (TCE) was accumulated as a major end product. This result means that amendment with extracellular secretions from Microbacterium shortened the lag phase, increased the dechlorination velocity and promoted the production of less-chlorinated chloroethene. The results were corroborated by defined subculture experiments, which proved that microorganisms from unamended mixed cultures could also be stimulated by extracellular secretions from Microbacterium. Desulfitobacterium was identified as the main dechlorinating population in all mixed cultures by direct PCR. Additionally, the 16S rRNA gene copies of Desulfitobacterium increased by one or two orders of magnitude with PCE dechlorination, which provided corroborative evidence for the identification result. The volatile fatty acids were monitored, and most interestingly, a close association between propionate oxidation and dechlorination was found, which has rarely been mentioned before. It was assumed that the oxidation of propionate provided hydrogen for dechlorination, while dechlorination facilitated the shift of the reaction toward propionate oxidation by reducing the partial pressure of hydrogen.
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Affiliation(s)
- Jixing Wan
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China; Zhejiang Provincial Key Laboratory for Water Pollution Control and Environmental Safety, Hangzhou, China
| | - Chen Chen
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China; Department of Civil and Environmental Engineering, National University of Singapore, Singapore
| | - Jingwen Chen
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China
| | - Qianyu Miao
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China
| | - Yindong Liu
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China
| | - Junxiang Ye
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China
| | - Kezhen Chen
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China
| | - Yiying Jin
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China
| | - Xianjin Tang
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China
| | - Chaofeng Shen
- Department of Environmental Engineering, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China; Zhejiang Provincial Key Laboratory for Water Pollution Control and Environmental Safety, Hangzhou, China.
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29
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Lechner U, Türkowsky D, Dinh TTH, Al‐Fathi H, Schwoch S, Franke S, Gerlach M, Koch M, von Bergen M, Jehmlich N, Dang TCH. Desulfitobacterium contributes to the microbial transformation of 2,4,5-T by methanogenic enrichment cultures from a Vietnamese active landfill. Microb Biotechnol 2018; 11:1137-1156. [PMID: 30117290 PMCID: PMC6196390 DOI: 10.1111/1751-7915.13301] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 07/07/2018] [Indexed: 12/17/2022] Open
Abstract
The herbicide 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) was a major component of Agent Orange, which was used as a defoliant in the Vietnam War. Little is known about its degradation under anoxic conditions. Established enrichment cultures using soil from an Agent Orange bioremediation plant in southern Vietnam with pyruvate as potential electron donor and carbon source were shown to degrade 2,4,5-T via ether cleavage to 2,4,5-trichlorophenol (2,4,5-TCP), which was further dechlorinated to 3,4-dichlorophenol. Pyruvate was initially fermented to hydrogen, acetate and propionate. Hydrogen was then used as the direct electron donor for ether cleavage of 2,4,5-T and subsequent dechlorination of 2,4,5-TCP. 16S rRNA gene amplicon sequencing indicated the presence of bacteria and archaea mainly belonging to the Firmicutes, Bacteroidetes, Spirochaetes, Chloroflexi and Euryarchaeota. Desulfitobacterium hafniense was identified as the dechlorinating bacterium. Metaproteomics of the enrichment culture indicated higher protein abundances of 60 protein groups in the presence of 2,4,5-T. A reductive dehalogenase related to RdhA3 of D. hafniense showed the highest fold change, supporting its function in reductive dehalogenation of 2,4,5-TCP. Despite an ether-cleaving enzyme not being detected, the inhibition of ether cleavage but not of dechlorination, by 2-bromoethane sulphonate, suggested that the two reactions are catalysed by different organisms.
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Affiliation(s)
- Ute Lechner
- Institute of Biology/MicrobiologyMartin‐Luther University Halle‐WittenbergHalleGermany
| | - Dominique Türkowsky
- Department of Molecular Systems BiologyHelmholtz Centre for Environmental Research – UFZLeipzigGermany
| | - Thi Thu Hang Dinh
- Vietnamese Academy of Science and TechnologyInstitute of BiotechnologyHanoiVietnam
- Present address:
Vietnamese Academy of Science and TechnologyGraduate University of Science and TechnologyHanoiVietnam
| | - Hassan Al‐Fathi
- Institute of Biology/MicrobiologyMartin‐Luther University Halle‐WittenbergHalleGermany
| | - Stefan Schwoch
- Institute of Biology/MicrobiologyMartin‐Luther University Halle‐WittenbergHalleGermany
| | - Stefan Franke
- Institute of Biology/MicrobiologyMartin‐Luther University Halle‐WittenbergHalleGermany
| | | | - Mandy Koch
- Institute of Chemistry/Food and Environmental ChemistryMartin‐Luther University Halle‐WittenbergHalleGermany
| | - Martin von Bergen
- Department of Molecular Systems BiologyHelmholtz Centre for Environmental Research – UFZLeipzigGermany
| | - Nico Jehmlich
- Department of Molecular Systems BiologyHelmholtz Centre for Environmental Research – UFZLeipzigGermany
| | - Thi Cam Ha Dang
- Vietnamese Academy of Science and TechnologyInstitute of BiotechnologyHanoiVietnam
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Xie Y, Chen L, Liu R, Tian J. Reduction of AOX in pharmaceutical wastewater in the cathode chamber of bio-electrochemical reactor. BIORESOURCE TECHNOLOGY 2018; 265:437-442. [PMID: 29935452 DOI: 10.1016/j.biortech.2018.06.034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 06/10/2018] [Accepted: 06/12/2018] [Indexed: 06/08/2023]
Abstract
A bio-electrochemical reactor (BER) operating at different cathode potentials ranging from -300 to -1000 mV (vs standard hydrogen electrode, SHE) was used to reduce adsorbable organic halogens (AOX) in pharmaceutical wastewater. Cathode polarization enriched the electron donor of the biological system. Thus, the AOX removal efficiency in the BER improved from 59.9% to 70.2%, and the AOX removal rate increased from 0.87 to 1.17 mg AOX/h when the cathode potential was reduced from -300 to -1000 mV with the addition of methyl viologen, a known redox mediator. The decrease of the cathode potential was also beneficial for methane production, and the inhibition of the methanogenic process enhanced the AOX removal. Additionally, cathode coulombic efficiency analysis demonstrated that the proportion of electrons used for AOX reduction decreases with decreasing potential, from 37.6% at -300 mV to 17.3% at -1000 mV, although the AOX removal efficiency improves.
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Affiliation(s)
- Yawei Xie
- School of Environment, Tsinghua University, Beijing 100084, China
| | - Lujun Chen
- School of Environment, Tsinghua University, Beijing 100084, China; Zhejiang Provincial Key Laboratory of Water Science and Technology, Zhejiang 314006, China.
| | - Rui Liu
- Zhejiang Provincial Key Laboratory of Water Science and Technology, Zhejiang 314006, China
| | - Jinping Tian
- School of Environment, Tsinghua University, Beijing 100084, China
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Němeček J, Steinová J, Špánek R, Pluhař T, Pokorný P, Najmanová P, Knytl V, Černík M. Thermally enhanced in situ bioremediation of groundwater contaminated with chlorinated solvents - A field test. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 622-623:743-755. [PMID: 29223901 DOI: 10.1016/j.scitotenv.2017.12.047] [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: 08/31/2017] [Revised: 12/04/2017] [Accepted: 12/04/2017] [Indexed: 06/07/2023]
Abstract
In situ bioremediation (ISB) using reductive dechlorination is a widely accepted but relatively slow approach compared to other technologies for the treatment of groundwater contaminated by chlorinated ethenes (CVOCs). Due to the known positive kinetic effect on microbial metabolism, thermal enhancement may be a viable means of accelerating ISB. We tested thermally enhanced ISB in aquifers situated in sandy saprolite and underlying fractured granite. The system comprised pumping, heating and subsequent injection of contaminated groundwater aiming at an aquifer temperature of 20-30°C. A fermentable substrate (whey) was injected in separate batches. The test was monitored using hydrochemical and molecular tools (qPCR and NGS). The addition of the substrate and increase in temperature resulted in a rapid increase in the abundance of reductive dechlorinators (e.g., Dehalococcoides mccartyi, Dehalobacter sp. and functional genes vcrA and bvcA) and a strong increase in CVOC degradation. On day 34, the CVOC concentrations decreased by 87% to 96% in groundwater from the wells most affected by the heating and substrate. On day 103, the CVOC concentrations were below the LOQ resulting in degradation half-lives of 5 to 6days. Neither an increase in biomarkers nor a distinct decrease in the CVOC concentrations was observed in a deep well affected by the heating but not by the substrate. NGS analysis detected Chloroflexi dechlorinating genera (Dehalogenimonas and GIF9 and MSBL5 clades) and other genera capable of anaerobic metabolic degradation of CVOCs. Of these, bacteria of the genera Acetobacterium, Desulfomonile, Geobacter, Sulfurospirillum, Methanosarcina and Methanobacterium were stimulated by the substrate and heating. In contrast, groundwater from the deep well (affected by heating only) hosted representatives of aerobic metabolic and aerobic cometabolic CVOC degraders. The test results document that heating of the treated aquifer significantly accelerated the treatment process but only in the case of an abundant substrate.
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Affiliation(s)
- Jan Němeček
- ENACON s.r.o., Krčská 16, CZ-140 00 Prague 4, Czech Republic; Technical University of Liberec, Studentská 2, CZ-461 17 Liberec, Czech Republic.
| | - Jana Steinová
- Technical University of Liberec, Studentská 2, CZ-461 17 Liberec, Czech Republic
| | - Roman Špánek
- Technical University of Liberec, Studentská 2, CZ-461 17 Liberec, Czech Republic
| | - Tomáš Pluhař
- Technical University of Liberec, Studentská 2, CZ-461 17 Liberec, Czech Republic
| | - Petr Pokorný
- ENACON s.r.o., Krčská 16, CZ-140 00 Prague 4, Czech Republic
| | - Petra Najmanová
- DEKONTA a.s., Volutová 2523, CZ-158 00 Prague 5, Czech Republic
| | - Vladislav Knytl
- DEKONTA a.s., Volutová 2523, CZ-158 00 Prague 5, Czech Republic
| | - Miroslav Černík
- Technical University of Liberec, Studentská 2, CZ-461 17 Liberec, Czech Republic
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Weatherill JJ, Atashgahi S, Schneidewind U, Krause S, Ullah S, Cassidy N, Rivett MO. Natural attenuation of chlorinated ethenes in hyporheic zones: A review of key biogeochemical processes and in-situ transformation potential. WATER RESEARCH 2018; 128:362-382. [PMID: 29126033 DOI: 10.1016/j.watres.2017.10.059] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Revised: 10/12/2017] [Accepted: 10/28/2017] [Indexed: 06/07/2023]
Abstract
Chlorinated ethenes (CEs) are legacy contaminants whose chemical footprint is expected to persist in aquifers around the world for many decades to come. These organohalides have been reported in river systems with concerning prevalence and are thought to be significant chemical stressors in urban water ecosystems. The aquifer-river interface (known as the hyporheic zone) is a critical pathway for CE discharge to surface water bodies in groundwater baseflow. This pore water system may represent a natural bioreactor where anoxic and oxic biotransformation process act in synergy to reduce or even eliminate contaminant fluxes to surface water. Here, we critically review current process understanding of anaerobic CE respiration in the competitive framework of hyporheic zone biogeochemical cycling fuelled by in-situ fermentation of natural organic matter. We conceptualise anoxic-oxic interface development for metabolic and co-metabolic mineralisation by a range of aerobic bacteria with a focus on vinyl chloride degradation pathways. The superimposition of microbial metabolic processes occurring in sediment biofilms and bulk solute transport delivering reactants produces a scale dependence in contaminant transformation rates. Process interpretation is often confounded by the natural geological heterogeneity typical of most riverbed environments. We discuss insights from recent field experience of CE plumes discharging to surface water and present a range of practical monitoring technologies which address this inherent complexity at different spatial scales. Future research must address key dynamics which link supply of limiting reactants, residence times and microbial ecophysiology to better understand the natural attenuation capacity of hyporheic systems.
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Affiliation(s)
| | - Siavash Atashgahi
- Laboratory of Microbiology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Uwe Schneidewind
- Department of Engineering Geology and Hydrogeology, RWTH Aachen University, Aachen, Germany
| | - Stefan Krause
- School of Geography, Earth and Environmental Science, University of Birmingham, UK
| | - Sami Ullah
- School of Geography, Earth and Environmental Science, University of Birmingham, UK
| | | | - Michael O Rivett
- Department of Civil and Environmental Engineering, University of Strathclyde, Glasgow, UK; GroundH(2)O Plus Ltd., Quinton, Birmingham, UK
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Chen G, Kleindienst S, Griffiths DR, Mack EE, Seger ES, Löffler FE. Mutualistic interaction between dichloromethane- and chloromethane-degrading bacteria in an anaerobic mixed culture. Environ Microbiol 2017; 19:4784-4796. [DOI: 10.1111/1462-2920.13945] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 09/19/2017] [Accepted: 09/22/2017] [Indexed: 01/02/2023]
Affiliation(s)
- Gao Chen
- Center for Environmental Biotechnology; University of Tennessee; Knoxville TN 37996 USA
- Department of Civil and Environmental Engineering; University of Tennessee; Knoxville TN 37996 USA
| | - Sara Kleindienst
- Center for Environmental Biotechnology; University of Tennessee; Knoxville TN 37996 USA
- Oak Ridge National Laboratory; University of Tennessee and Oak Ridge National Laboratory (UT-ORNL) Joint Institute for Biological Sciences (JIBS) and Biosciences Division; Oak Ridge TN 37831 USA
- Center for Applied Geosciences; Department of Geosciences, Eberhard Karls University Tübingen; Tübingen 72074 Germany
| | | | - E. Erin Mack
- Corporate Remediation Group; E. I. DuPont de Nemours and Company; Wilmington DE 19805 USA
| | | | - Frank E. Löffler
- Center for Environmental Biotechnology; University of Tennessee; Knoxville TN 37996 USA
- Department of Civil and Environmental Engineering; University of Tennessee; Knoxville TN 37996 USA
- Oak Ridge National Laboratory; University of Tennessee and Oak Ridge National Laboratory (UT-ORNL) Joint Institute for Biological Sciences (JIBS) and Biosciences Division; Oak Ridge TN 37831 USA
- Department of Microbiology; University of Tennessee; Knoxville TN 37996 USA
- Department of Biosystems Engineering and Soil Science; University of Tennessee; Knoxville TN 37996 USA
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Mortan SH, Martín-González L, Vicent T, Caminal G, Nijenhuis I, Adrian L, Marco-Urrea E. Detoxification of 1,1,2-trichloroethane to ethene in a bioreactor co-culture of Dehalogenimonas and Dehalococcoides mccartyi strains. JOURNAL OF HAZARDOUS MATERIALS 2017; 331:218-225. [PMID: 28273571 DOI: 10.1016/j.jhazmat.2017.02.043] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Revised: 01/30/2017] [Accepted: 02/23/2017] [Indexed: 06/06/2023]
Abstract
1,1,2-Trichloroethane (1,1,2-TCA) is a non-flammable organic solvent and common environmental contaminant in groundwater. Organohalide-respiring bacteria are key microorganisms to remediate 1,1,2-TCA because they can gain metabolic energy during its dechlorination under anaerobic conditions. However, all current isolates produce hazardous end products such as vinyl chloride, monochloroethane or 1,2-dichloroethane that accumulate in the medium. Here, we constructed a syntrophic co-culture of Dehalogenimonas and Dehalococcoides mccartyi strains to achieve complete detoxification of 1,1,2-TCA to ethene. In this co-culture, Dehalogenimonas transformed 1,1,2-TCA via dihaloelimination to vinyl chloride, whereas Dehalococcoides reduced vinyl chloride via hydrogenolysis to ethene. Molasses, pyruvate, and lactate supported full dechlorination of 1,1,2-TCA in serum bottle co-cultures. Scale up of the cultivation to a 5-L bioreactor operating for 76d in fed-batch mode was successful with pyruvate as substrate. This synthetic combination of bacteria with known complementary metabolic capabilities demonstrates the potential environmental relevance of microbial cooperation to detoxify 1,1,2-TCA.
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Affiliation(s)
- Siti Hatijah Mortan
- Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona (UAB), Bellaterra, Barcelona, Spain
| | - Lucía Martín-González
- Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona (UAB), Bellaterra, Barcelona, Spain
| | - Teresa Vicent
- Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona (UAB), Bellaterra, Barcelona, Spain
| | - Gloria Caminal
- Institut de Química Avançada de Catalunya (IQAC) CSIC, Barcelona, Spain
| | - Ivonne Nijenhuis
- Department Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Lorenz Adrian
- Department Isotope Biogeochemistry, Helmholtz Centre for Environmental Research-UFZ, Leipzig, Germany
| | - Ernest Marco-Urrea
- Departament d'Enginyeria Química, Biològica i Ambiental, Universitat Autònoma de Barcelona (UAB), Bellaterra, Barcelona, Spain.
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Mayer-Blackwell K, Azizian MF, Green JK, Spormann AM, Semprini L. Survival of Vinyl Chloride Respiring Dehalococcoides mccartyi under Long-Term Electron Donor Limitation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:1635-1642. [PMID: 28002948 DOI: 10.1021/acs.est.6b05050] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
In anoxic groundwater aquifers, the long-term survival of Dehalococcoides mccartyi populations expressing the gene vcrA (or bvcA) encoding reductive vinyl chloride dehalogenases are important to achieve complete dechlorination of tetrachloroethene (PCE) and trichloroethene (TCE) to nonchlorinated ethene. The absence or inactivity of vcrA-containing Dehalococcoides results in the accumulation of the harmful chlorinated intermediates dichloroethene (DCE) and vinyl chloride (VC). Although vcrA-containing Dehalococcoides subpopulations depend on synergistic interaction with other organohalide-respiring populations generating their metabolic electron acceptors (DCE and VC), their survival requires successful competition for electron donor within the entire organohalide-respiring microbial community. To understand this dualism of synergy and competition under growth conditions relevant in contaminated aquifers, we investigated Dehalococcoides-level population structure when subjected to a change in the ratio of electron donor to chlorinated electron acceptor in continuously stirred tank reactors (CSTRs) operated over 7 years. When the electron donor formate was supplied in stoichiometric excess to TCE, both tceA-containing and vcrA-containing Dehalococcoides populations persisted, and near-complete dechlorination to ethene was stably maintained. When the electron donor formate was supplied at substoichiometric concentrations, the interactions between tceA-containing and vcrA-containing populations shifted toward direct competition for the same limiting catabolic electron donor substrate with subsequent niche exclusion of the vcrA-containing population. After more than 2000 days of operation under electron donor limitation, increasing the electron donor to TCE ratio facilitated a recovery of the vcrA-containing Dehalococoides population to its original frequency. We demonstrate that electron donor scarcity alone, in the absence of competing metabolic processes or inhibitory dechlorination intermediate products, is sufficient to alter the Dehalococcoides population structure. These results underscore the importance of electron donor and chloroethene stoichiometry in maintaining balanced functional performance within consortia composed of multiple D. mccartyi subpopulations, even when other competing electron acceptor processes are absent.
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Affiliation(s)
| | - Mohammad F Azizian
- Chemical, Biological and Environmental Engineering, Oregon State University , Corvallis, Oregon 97331, United States
| | - Jennifer K Green
- Chemical, Biological and Environmental Engineering, Oregon State University , Corvallis, Oregon 97331, United States
| | | | - Lewis Semprini
- Chemical, Biological and Environmental Engineering, Oregon State University , Corvallis, Oregon 97331, United States
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36
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Leng RA. Biofilm compartmentalisation of the rumen microbiome: modification of fermentation and degradation of dietary toxins. ANIMAL PRODUCTION SCIENCE 2017. [DOI: 10.1071/an17382] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Many deleterious chemicals in plant materials ingested by ruminants produce clinical effects, varying from losses of production efficiency through to death. Many of the effects are insidious, often going unrecognised by animal managers. When secondary plant compounds enter the rumen, they may undergo modification by rumen microbes, which often removes the deleterious compounds, but in specific instances, the deleterious effect may be enhanced. Improved understanding of rumen ecology, particularly concerning the biofilm mode of microbial fermentation, has led to major advances in our understanding of fermentation. In the present review, the potential impact of the physical structuring of the rumen microbiome is discussed in relation to how several economically important secondary plant compounds and other toxins are metabolised by the rumen microbiome and how their toxic effects may be remedied by providing inert particles with a large surface area to weight ratio in the diet. These particles provide additional surfaces for attachment of rumen microorganisms that help alleviate toxicity problems associated with deleterious compounds, including fluoroacetate, mimosine, mycotoxins, cyanoglycosides and hydrogen cyanide. The review first summarises the basic science of biofilm formation and describes the properties of biofilms and their roles in the rumen. It then addresses how biofilms on inert solids and fermentable particulates may assist in detoxification of potentially toxic compounds. A hypothesis that explains how nitrate poisoning may occur as a result of compartmentalisation of nitrate and nitrite reduction in the rumen is included.
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37
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Wang S, Chen S, Wang Y, Low A, Lu Q, Qiu R. Integration of organohalide-respiring bacteria and nanoscale zero-valent iron (Bio-nZVI-RD): A perfect marriage for the remediation of organohalide pollutants? Biotechnol Adv 2016; 34:1384-1395. [DOI: 10.1016/j.biotechadv.2016.10.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 09/18/2016] [Accepted: 10/15/2016] [Indexed: 12/19/2022]
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38
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Rónavári A, Balázs M, Tolmacsov P, Molnár C, Kiss I, Kukovecz Á, Kónya Z. Impact of the morphology and reactivity of nanoscale zero-valent iron (NZVI) on dechlorinating bacteria. WATER RESEARCH 2016; 95:165-73. [PMID: 26994337 DOI: 10.1016/j.watres.2016.03.019] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 03/04/2016] [Accepted: 03/08/2016] [Indexed: 01/10/2023]
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39
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Liu CY, Cade-Menun BJ, Xu XH, Fan JL. Electron Donor Substances and Iron Oxides Stimulate Anaerobic Dechlorination of DDT in a Slurry System with Hydragric Acrisols. JOURNAL OF ENVIRONMENTAL QUALITY 2016; 45:331-340. [PMID: 26828189 DOI: 10.2134/jeq2015.07.0406] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The interactive effects between electron donor substances and iron (Fe) oxides have significant influence on electron transfer and the growth of Fe-reducing bacteria, which may affect the reductive dechlorination of 1,1,1-trichoro-2,2-bis(p-chlorophenyl)ethane (DDT) in soils. To evaluate the roles of volatile fatty acids and Fe(III) oxide in accelerating the reductive dechlorination of DDT in Hydragric Acrisols, a batch anaerobic incubation experiment was conducted in a slurry system with the following seven treatments: sterile soil, control (DDT-contaminated soil), lactic acid, propionic acid, goethite, lactic acid + goethite, and propionic acid + goethite. Results showed that after 20 d of incubation, DDT residues for these treatments decreased by 34, 65, 77, 81, 77, 90, and 92% of the initial quantities, respectively, with 1,1-dichloro-2,2-bis(4-chlorophenyl)-ethane as the dominant metabolite. The application of lactic acid had no significant effect on DDT dechlorination in the first 8 d while the methanogenesis rate increased quickly but accelerated DDT dechlorination after Day 8 while the methanogenesis rate decreased and Fe(II) contents increased. The application of propionic acid enhanced DDT dechlorination rates throughout the incubation. The amendment by goethite stimulated microbial reduction of Fe(III) oxides to generate Fe(II), which was an efficient electron donor, thus accelerating DDT dechlorination significantly in the early incubation period. A synergetic interaction that accelerated DDT dechlorination, either between lactic acid and goethite or between propionic acid and goethite, was obtained. The results will be of great significance to develop efficient in situ remediation technology of DDT-contaminated soil.
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40
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Liu C, Xu X, Fan J. Accelerated anaerobic dechlorination of DDT in slurry with Hydragric Acrisols using citric acid and anthraquinone-2,6-disulfonate (AQDS). J Environ Sci (China) 2015; 38:87-94. [PMID: 26702971 DOI: 10.1016/j.jes.2015.05.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 05/05/2015] [Accepted: 05/11/2015] [Indexed: 06/05/2023]
Abstract
The application of electron donor and electron shuttle substances has a vital influence on electron transfer, thus may affect the reductive dechlorination of 1,1,1-trichoro-2,2-bis(p-chlorophenyl)ethane (DDT) in anaerobic reaction systems. To evaluate the roles of citric acid and anthraquinone-2,6-disulfonate (AQDS) in accelerating the reductive dechlorination of DDT in Hydragric Acrisols that contain abundant iron oxide, a batch anaerobic incubation experiment was conducted in a slurry system with four treatments of (1) control, (2) citric acid, (3) AQDS, and (4) citric acid+AQDS. Results showed that DDT residues decreased by 78.93%-92.11% of the initial quantities after 20days of incubation, and 1,1-dichloro-2,2-bis(4-chlorophenyl)-ethane (DDD) was the dominant metabolite. The application of citric acid accelerated DDT dechlorination slightly in the first 8days, while the methanogenesis rate increased quickly, and then the acceleration effect improved after the 8th day while the methanogenesis rate decreased. The amendment by AQDS decreased the Eh value of the reaction system and accelerated microbial reduction of Fe(III) oxides to generate Fe(II), which was an efficient electron donor, thus enhancing the reductive dechlorination rate of DDT. The addition of citric acid+AQDS was most efficient in stimulating DDT dechlorination, but no significant interaction between citric acid and AQDS on DDT dechlorination was observed. The results will be of great significance for developing an efficient in situ remediation strategy for DDT-contaminated sites.
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Affiliation(s)
- Cuiying Liu
- Jiangsu Key Laboratory of Agricultural Meteorology, College of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing 210044, China.
| | - Xianghua Xu
- Jiangsu Key Laboratory of Agricultural Meteorology, College of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing 210044, China
| | - Jianling Fan
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China
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41
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Mirza BS, Sorensen DL, Dupont RR, McLean JE. Dehalococcoides abundance and alternate electron acceptor effects on large, flow-through trichloroethene dechlorinating columns. Appl Microbiol Biotechnol 2015; 100:2367-79. [PMID: 26536878 DOI: 10.1007/s00253-015-7112-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 10/18/2015] [Accepted: 10/20/2015] [Indexed: 11/25/2022]
Abstract
Trichloroethene (TCE) in groundwater is a major health concern and biostimulation/bioaugmentation-based strategies have been evaluated to achieve complete reductive dechlorination with varying success. Different carbon sources were hypothesized to stimulate different extents of TCE reductive dechlorination. Ecological conditions that developed different dechlorination stages were investigated by quantitating Dehalococcoides 16S rRNA (Dhc) and reductive dehalogenase gene abundance, and by describing biogeochemical properties of laboratory columns in response to this biostimulation. Eight large columns (183 cm × 15.2 cm), packed with aquifer material from Hill AFB, Utah, that were continuously fed TCE for 7.5 years. Duplicate columns were biostimulated with whey or one of two different Newman Zone® emulsified oil formulations containing either nonionic surfactant (EOLN) or standard surfactant (EOL). Two columns were non-stimulated controls. Complete (whey amended), partial (EOLN amended), limited (EOL), and non-TCE dehalogenating systems (controls) developed over the course of the study. Bioaugmentation of half of the columns with Bachman Road culture 3 years prior to dismantling did not influence the extent of TCE dehalogenation. Multivariate analysis clustered samples by biostimulation treatments and extent of TCE dehalogenation. Dhc, tceA, and bvcA gene concentrations did not show a consistent relationship with TCE dehalogenation but the vcrA gene was more abundant in completely dehalogenating, whey-treated columns. The whey columns developed strongly reducing conditions producing Fe(II), sulfide, and methane. Biostimulation with different carbon and energy sources can support high concentrations of diverse Dhc, but carbon addition has a major influence on biogeochemical processes effecting the extent of TCE dehalogenation.
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Affiliation(s)
- Babur S Mirza
- Utah Water Research Laboratory, Utah State University, Logan, UT, 84322-8200, USA
| | - Darwin L Sorensen
- Utah Water Research Laboratory, Utah State University, Logan, UT, 84322-8200, USA
| | - R Ryan Dupont
- Utah Water Research Laboratory, Utah State University, Logan, UT, 84322-8200, USA.,Department of Civil and Environmental Engineering, Utah State University, Logan, UT, 84322-8200, USA
| | - Joan E McLean
- Utah Water Research Laboratory, Utah State University, Logan, UT, 84322-8200, USA. .,Department of Civil and Environmental Engineering, Utah State University, Logan, UT, 84322-8200, USA.
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42
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Türke A, Nakamura K, Bach W. Palagonitization of Basalt Glass in the Flanks of Mid-Ocean Ridges: Implications for the Bioenergetics of Oceanic Intracrustal Ecosystems. ASTROBIOLOGY 2015; 15:793-803. [PMID: 26426282 DOI: 10.1089/ast.2014.1255] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
When basalt is exposed to oxygenated aqueous solutions, rims of palagonite form along fractures at the expense of glass. We employed electron microprobe and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analyses of fresh glass and adjacent palagonite crusts to determine the geochemical changes involved in palagonite formation. Samples were retrieved from drill cores taken in the North Pond Area, located on the western flank of the Mid-Atlantic Ridge at 22°45'N and 46°05'W. We also analyzed whole rock powders to determine the overall crust-seawater exchange in a young ridge flank. Radioactive elements are enriched in palagonite relative to fresh glass, reaching concentrations where radiolytic production of molecular hydrogen (H2) may be a significant energy source. Based on these results, we hypothesize that microbial ecosystems in ridge flank habitats undergo a transition in the principal energy carrier, fueling carbon fixation from Fe oxidation in very young crust to H2 consumption in older crust. Unless the H2 is swept away by rapid fluid flow (i.e., in young flanks), it may easily accumulate to levels high enough to support chemolithoautotrophic life. In older flanks, crustal sealing and sediment accumulation have slowed down seawater circulation, and the significance of radiolytically produced H2 for catalytic energy supply is expected to increase greatly. Similar habitats on other planetary surfaces are theoretically possible, as accumulation of radiolytically produced hydrogen merely requires the presence of H2O molecules and a porous medium, from which the hydrogen is not lost.
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Affiliation(s)
- Andreas Türke
- 1 Department of Geosciences and MARUM, University of Bremen , Bremen, Germany
| | - Kentaro Nakamura
- 2 Department of Systems Innovation, School of Engineering, The University of Tokyo , Tokyo, Japan
| | - Wolfgang Bach
- 1 Department of Geosciences and MARUM, University of Bremen , Bremen, Germany
- 3 Centre of Excellence in Geobiology and the Department of Earth Sciences, Realfagbygget, University of Bergen , Bergen, Norway
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43
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Verdini R, Aulenta F, de Tora F, Lai A, Majone M. Relative contribution of set cathode potential and external mass transport on TCE dechlorination in a continuous-flow bioelectrochemical reactor. CHEMOSPHERE 2015; 136:72-8. [PMID: 25950501 DOI: 10.1016/j.chemosphere.2015.03.092] [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: 12/23/2014] [Revised: 03/24/2015] [Accepted: 03/25/2015] [Indexed: 05/28/2023]
Abstract
Microbial bioelectrochemical systems, which use solid-state cathodes to drive the reductive degradation of contaminants such as the chlorinated hydrocarbons, are recently attracting considerable attention for bioremediation applications. So far, most of the published research has focused on analyzing the influence of key (bio)electrochemical factors influencing contaminant degradation, such as the cathode potential, whereas only few studies have examined the potential impact of mass transport phenomena on process performance. Here we analyzed the performance of a flow-through bioelectrochemical reactor, continuously fed with a synthetic groundwater containing trichloroethene at three different linear fluid velocities (from 0.3 m d(-1) to 1.7 m d(-1)) and three different set cathode potentials (from -250 mV to -450 mV vs. the standard hydrogen electrode). The obtained results demonstrated that, in the range of fluid velocities which are characteristics for natural groundwater systems, mass transport phenomena may strongly influence the rate and extent of reductive dechlorination. Nonetheless, the relative importance of mass transport largely depends on the applied cathode potential which, in turn, controls the intrinsic kinetics of biological reactions and the underlying electron transfer mechanisms.
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Affiliation(s)
- Roberta Verdini
- Department of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Roma, Italy.
| | - Federico Aulenta
- Water Research Institute (IRSA), National Research Council (CNR), via Salaria km 29.300, 00015 Monterotondo (RM), Italy
| | - Francesca de Tora
- Department of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Roma, Italy
| | - Agnese Lai
- Department of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Roma, Italy
| | - Mauro Majone
- Department of Chemistry, Sapienza University of Rome, Piazzale Aldo Moro 5, 00185 Roma, Italy
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Lai A, Verdini R, Aulenta F, Majone M. Influence of nitrate and sulfate reduction in the bioelectrochemically assisted dechlorination of cis-DCE. CHEMOSPHERE 2015; 125:147-154. [PMID: 25556008 DOI: 10.1016/j.chemosphere.2014.12.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 12/04/2014] [Accepted: 12/05/2014] [Indexed: 06/04/2023]
Abstract
This paper investigated the reductive dechlorination (RD) of cis-dichloroethylene (cis-DCE) (average influent 14.2±0.7 μM) by a bioelectrochemical system (BES), in the presence of real contaminated groundwater containing high levels of nitrate and sulfate. The BES enhanced both the RD and competing reactions, such as nitrate and sulfate reductions, which occurred with neither an external organic carbon source nor any inoculum other than the indigenous microbial consortia in the real groundwater. In preliminary batch tests, RD and full nitrate removal occurred after a short lag phase, whereas sulfate reduction occurred slowly and alongside the RD. Under continuous flow conditions (hydraulic retention time, HRT, 1.4 d), the competition of different electron acceptors was strongly affected by the cathodic potential in the range -550 to -750 mV vs. standard hydrogen electrode (SHE). Nitrate reduction was driven to completion at all tested cathodic potentials, whereas sulfate reduction and the RD rate increased as the cathodic potential became more negative. At -750 mV vs. SHE, strong methanogenesis was also observed and became the most important sink of electrons. The overall coulombic efficiency decreased while the potential became more negative. The RD contribution was always less than 1%. Hence, greater energy consumption was required to obtain higher RD rate and better conversion. Anodic oxidation was only observed at -750 mV vs. SHE where almost 39% of residual vinyl chloride (VC) was oxidized and the sulfate was formed back from sulfide (further contributing to electric waste).
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Affiliation(s)
- Agnese Lai
- Department of Chemistry, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy
| | - Roberta Verdini
- Department of Chemistry, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy.
| | - Federico Aulenta
- Water Research Institute (IRSA-CNR), National Research Council, 00016 Monterotondo, RM, Italy
| | - Mauro Majone
- Department of Chemistry, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy
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Mao X, Stenuit B, Polasko A, Alvarez-Cohen L. Efficient metabolic exchange and electron transfer within a syntrophic trichloroethene-degrading coculture of Dehalococcoides mccartyi 195 and Syntrophomonas wolfei. Appl Environ Microbiol 2015; 81:2015-24. [PMID: 25576615 PMCID: PMC4345365 DOI: 10.1128/aem.03464-14] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 01/02/2015] [Indexed: 01/07/2023] Open
Abstract
Dehalococcoides mccartyi 195 (strain 195) and Syntrophomonas wolfei were grown in a sustainable syntrophic coculture using butyrate as an electron donor and carbon source and trichloroethene (TCE) as an electron acceptor. The maximum dechlorination rate (9.9 ± 0.1 μmol day(-1)) and cell yield [(1.1 ± 0.3) × 10(8) cells μmol(-1) Cl(-)] of strain 195 maintained in coculture were, respectively, 2.6 and 1.6 times higher than those measured in the pure culture. The strain 195 cell concentration was about 16 times higher than that of S. wolfei in the coculture. Aqueous H2 concentrations ranged from 24 to 180 nM during dechlorination and increased to 350 ± 20 nM when TCE was depleted, resulting in cessation of butyrate fermentation by S. wolfei with a theoretical Gibbs free energy of -13.7 ± 0.2 kJ mol(-1). Carbon monoxide in the coculture was around 0.06 μmol per bottle, which was lower than that observed for strain 195 in isolation. The minimum H2 threshold value for TCE dechlorination by strain 195 in the coculture was 0.6 ± 0.1 nM. Cell aggregates during syntrophic growth were observed by scanning electron microscopy. The interspecies distances to achieve H2 fluxes required to support the measured dechlorination rates were predicted using Fick's law and demonstrated the need for aggregation. Filamentous appendages and extracellular polymeric substance (EPS)-like structures were present in the intercellular spaces. The transcriptome of strain 195 during exponential growth in the coculture indicated increased ATP-binding cassette transporter activities compared to the pure culture, while the membrane-bound energy metabolism related genes were expressed at stable levels.
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Affiliation(s)
- Xinwei Mao
- Department of Civil and Environmental Engineering, College of Engineering, University of California, Berkeley, Berkeley, California, USA
| | - Benoit Stenuit
- Department of Civil and Environmental Engineering, College of Engineering, University of California, Berkeley, Berkeley, California, USA
| | - Alexandra Polasko
- Department of Civil and Environmental Engineering, College of Engineering, University of California, Berkeley, Berkeley, California, USA
| | - Lisa Alvarez-Cohen
- Department of Civil and Environmental Engineering, College of Engineering, University of California, Berkeley, Berkeley, California, USA Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
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Puigserver D, Cortés A, Viladevall M, Nogueras X, Parker BL, Carmona JM. Processes controlling the fate of chloroethenes emanating from DNAPL aged sources in river-aquifer contexts. JOURNAL OF CONTAMINANT HYDROLOGY 2014; 168:25-40. [PMID: 25278314 DOI: 10.1016/j.jconhyd.2014.09.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Revised: 09/04/2014] [Accepted: 09/09/2014] [Indexed: 06/03/2023]
Abstract
This work dealt with the physical and biogeochemical processes that favored the natural attenuation of chloroethene plumes of aged sources located close to influent rivers in the presence of co-contaminants, such as nitrate and sulfate. Two working hypotheses were proposed: i) Reductive dechlorination is increased in areas where the river-aquifer relationship results in the groundwater dilution of electron acceptors, the reduction potential of which exceeds that of specific chloroethenes; ii) zones where silts predominate or where textural changes occur are zones in which biodegradation preferentially takes place. A field site on a Quaternary alluvial aquifer at Torelló, Catalonia (Spain) was selected to validate these hypotheses. This aquifer is adjacent to an influent river, and its redox conditions favor reductive dechlorination. The main findings showed that the low concentrations of nitrate and sulfate due to dilution caused by the input of surface water diminish the competition for electrons between microorganisms that reduce co-contaminants and chloroethenes. Under these conditions, the most bioavailable electron acceptors were PCE and metabolites, which meant that their biodegradation was favored. This led to the possibility of devising remediation strategies based on bioenhancing natural attenuation. The artificial recharge with water that is low in nitrates and sulfates may favor dechlorinating microorganisms if the redox conditions in the mixing water are sufficiently maintained as reducing and if there are nutrients, electron donors and carbon sources necessary for these microorganisms.
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Affiliation(s)
- Diana Puigserver
- Dept. de Gequímica, Petrologia i Prospecció Geològica, Facultat de Geologia, Universitat de Barcelona, C/Martí i Franquès, s/n, E-08028 Barcelona, Spain.
| | - Amparo Cortés
- Dept. de Productes Naturals, Biologia Vegetal i Edafologia, Facultat de Farmàcia, Universitat de Barcelona, Av. Joan XXIII, s/n, E-08028 Barcelona, Spain.
| | - Manuel Viladevall
- Dept. de Gequímica, Petrologia i Prospecció Geològica, Facultat de Geologia, Universitat de Barcelona, C/Martí i Franquès, s/n, E-08028 Barcelona, Spain.
| | - Xènia Nogueras
- Dept. de Gequímica, Petrologia i Prospecció Geològica, Facultat de Geologia, Universitat de Barcelona, C/Martí i Franquès, s/n, E-08028 Barcelona, Spain.
| | - Beth L Parker
- School of Engineering, University of Guelph, NIG 2W1 Guelph, ON, Canada.
| | - José M Carmona
- Dept. de Gequímica, Petrologia i Prospecció Geològica, Facultat de Geologia, Universitat de Barcelona, C/Martí i Franquès, s/n, E-08028 Barcelona, Spain.
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Enrichment and Characterization of a Trichloroethene-Dechlorinating Consortium Containing Multiple “Dehalococcoides” Strains. Biosci Biotechnol Biochem 2014; 75:1268-74. [DOI: 10.1271/bbb.110028] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Schneidewind U, Haest PJ, Atashgahi S, Maphosa F, Hamonts K, Maesen M, Calderer M, Seuntjens P, Smidt H, Springael D, Dejonghe W. Kinetics of dechlorination by Dehalococcoides mccartyi using different carbon sources. JOURNAL OF CONTAMINANT HYDROLOGY 2014; 157:25-36. [PMID: 24275111 DOI: 10.1016/j.jconhyd.2013.10.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 10/05/2013] [Accepted: 10/18/2013] [Indexed: 06/02/2023]
Abstract
Stimulated anaerobic dechlorination is generally considered a valuable step for the remediation of aquifers polluted with chlorinated ethenes (CEs). Correct simulation and prediction of this process in situ, however, require good knowledge of the associated biological reactions. The aim of this study was to evaluate the dechlorination reaction in an aquifer contaminated with trichloroethene (TCE) and its daughter products, discharging into the Zenne River. Different carbon sources were used in batch cultures and these were related to the dechlorination reaction, together with the monitored biomarkers. Appropriate kinetic formulations were assessed. Reductive dechlorination of TCE took place only when external carbon sources were added to microcosms, and occurred concomitant with a pronounced increase in the Dehalococcoides mccartyi cell count as determined by 16S rRNA gene-targeted qPCR. This indicates that native dechlorinating bacteria are present in the aquifer of the Zenne site and that the oligotrophic nature of the aquifer prevents a complete degradation to ethene. The type of carbon source, the cell number of D. mccartyi or the reductive dehalogenase genes, however, did not unequivocally explain the observed differences in degradation rates or the extent of dechlorination. Neither first-order, Michaelis-Menten nor Monod kinetics could perfectly simulate the dechlorination reactions in TCE spiked microcosms. A sensitivity analysis indicated that the inclusion of donor limitation would not significantly enhance the simulations without a clear process understanding. Results point to the role of the supporting microbial community but it remains to be verified how the complexity of the microbial (inter)actions should be represented in a model framework.
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Affiliation(s)
- Uwe Schneidewind
- Flemish Institute for Technological Research (VITO), Environmental Modeling Unit, Boeretang 200, 2400 Mol, Belgium; Ghent University, Department of Soil Management, Coupure Links 653, 9000 Ghent, Belgium
| | - Pieter Jan Haest
- Flemish Institute for Technological Research (VITO), Separation and Conversion Technology, Boeretang 200, 2400 Mol, Belgium
| | - Siavash Atashgahi
- Flemish Institute for Technological Research (VITO), Separation and Conversion Technology, Boeretang 200, 2400 Mol, Belgium; Wageningen University, Laboratory of Microbiology, 6703 HB Wageningen, The Netherlands; KU Leuven, Division Soil and Water Management, Kasteelpark Arenberg 20, 3001 Heverlee, Belgium
| | - Farai Maphosa
- Wageningen University, Laboratory of Microbiology, 6703 HB Wageningen, The Netherlands
| | - Kelly Hamonts
- Flemish Institute for Technological Research (VITO), Separation and Conversion Technology, Boeretang 200, 2400 Mol, Belgium
| | - Miranda Maesen
- Flemish Institute for Technological Research (VITO), Separation and Conversion Technology, Boeretang 200, 2400 Mol, Belgium
| | - Montse Calderer
- Manresa Technology Centre - CTM, Environmental Technology Area, Av. Bases de Manresa, 08242 Manresa, Spain
| | - Piet Seuntjens
- Flemish Institute for Technological Research (VITO), Environmental Modeling Unit, Boeretang 200, 2400 Mol, Belgium; Ghent University, Department of Soil Management, Coupure Links 653, 9000 Ghent, Belgium; University of Antwerp, Department of Bioscience Engineering, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Hauke Smidt
- Wageningen University, Laboratory of Microbiology, 6703 HB Wageningen, The Netherlands
| | - Dirk Springael
- KU Leuven, Division Soil and Water Management, Kasteelpark Arenberg 20, 3001 Heverlee, Belgium
| | - Winnie Dejonghe
- Flemish Institute for Technological Research (VITO), Separation and Conversion Technology, Boeretang 200, 2400 Mol, Belgium.
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Viotti P, Di Palma PR, Aulenta F, Luciano A, Mancini G, Papini MP. Use of a reactive transport model to describe reductive dechlorination (RD) as a remediation design tool: application at a CAH-contaminated site. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2014; 21:1514-1527. [PMID: 23933954 DOI: 10.1007/s11356-013-2035-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2013] [Accepted: 07/22/2013] [Indexed: 06/02/2023]
Abstract
In this paper, a numerical model is presented that is capable of describing the complex set of biochemical processes that occur in chlorinated aliphatic hydrocarbon (CAH)-contaminated groundwater when an exogenous electron donor is added. The reactive pattern is based on the degradation pathways of both chlorinated ethanes and ethenes, and it includes electron donor production (H2 and acetate) from the fermentation of an organic substrate as well as rate-limiting processes related to electron acceptor competition. Coupling of the kinetic model to a convection-dispersion module is described. The calibration phase was carried out using data obtained at a real CAH-contaminated site in the north of Italy. Model simulations of different application scenarios are presented to draw general conclusions on the effectiveness of reductive dechlorination (RD) as a possible cleanup strategy. Early outcomes indicate that cleanup targets can only be achieved if source longevity is reduced. Therefore, metabolic RD is expected to produce beneficial effects because it is known to induce bioenhanced degradation and transformation of CAHs.
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Affiliation(s)
- Paolo Viotti
- Department of Civil, Building and Environmental Engineering, Sapienza University of Rome, Via Eudossiana 18, 00184, Rome, Italy,
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Hong J, Tezel U, Okutman Tas D, Pavlostathis SG. Influence of quaternary ammonium compounds on the microbial reductive dechlorination of pentachloroaniline. WATER RESEARCH 2013; 47:6780-6789. [PMID: 24075473 DOI: 10.1016/j.watres.2013.09.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 09/01/2013] [Accepted: 09/05/2013] [Indexed: 06/02/2023]
Abstract
The inhibitory effect of two widely used quaternary ammonium compounds (QACs)--alkyl benzyl dimethyl (AB) and hexadecyl trimethyl (HD) ammonium chloride--on fermentation, methanogenesis and pentachloroaniline (PCA) dechlorination was assessed using a mixed, methanogenic, PCA-dechlorinating culture amended with AB or HD at a concentration range from 5 to 70 μM. PCA dechlorination was inhibited at 5 μM AB and was completely inhibited at 25 or 5 μM by AB or HD, respectively. However, the PCA dechlorination pathway was the same in both the QACs-free and QACs-amended culture series. Fermentation (acidogenesis) and methanogenesis were inhibited by both AB and HD at and above 25 μM but to a lesser degree than PCA dechlorination. Overall, HD resulted in a more severe inhibition of the mixed culture than AB. Adsorption of both QACs to the mixed culture biomass followed the Freundlich isotherm model. The adsorption affinity of HD for the mixed culture biomass was significantly higher than that of AB, which may be related to the observed higher inhibitory effects of HD compared to AB. Both AB and HD were not degraded in the mixed, dechlorinating culture used in this study.
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Affiliation(s)
- Jinglan Hong
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0512, USA; School of Environmental Science and Engineering, Shandong University, 250100 Jinan, China
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