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Hedegaard MJ, Deliniere H, Prasse C, Dechesne A, Smets BF, Albrechtsen HJ. Evidence of co-metabolic bentazone transformation by methanotrophic enrichment from a groundwater-fed rapid sand filter. WATER RESEARCH 2018; 129:105-114. [PMID: 29136518 DOI: 10.1016/j.watres.2017.10.073] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 10/27/2017] [Accepted: 10/31/2017] [Indexed: 06/07/2023]
Abstract
The herbicide bentazone is recalcitrant in aquifers and is therefore frequently detected in wells used for drinking water production. However, bentazone degradation has been observed in filter sand from a rapid sand filter at a waterworks with methane-rich groundwater. Here, the association between methane oxidation and removal of bentazone was investigated with a methanotrophic enrichment culture derived from methane-fed column reactors inoculated with that filter sand. Several independent lines of evidence obtained from microcosm experiments with the methanotrophic enrichment culture, tap water and bentazone at concentrations below 2 mg/L showed methanotrophic co-metabolic bentazone transformation: The culture removed 53% of the bentazone in 21 days in presence of 5 mg/L of methane, while only 31% was removed in absence of methane. Addition of acetylene inhibited methane oxidation and stopped bentazone removal. The presence of bentazone partly inhibited methane oxidation since the methane consumption rate was significantly lower at high (1 mg/L) than at low (1 μg/L) bentazone concentrations. The transformation yield of methane relative to bentazone normalized by their concentration ratio ranged from 58 to 158, well within the range for methanotrophic co-metabolic degradation of trace contaminants calculated from the literature, with normalized substrate preferences varying from 3 to 400. High-resolution mass spectrometry revealed formation of the transformation products (TPs) 6-OH, 8-OH, isopropyl-OH and di-OH-bentazone, with higher abundances of all TPs in the presence of methane. Overall, we found a suite of evidence all showing that bentazone was co-metabolically transformed to hydroxy-bentazone by a methanotrophic culture enriched from a rapid sand filter at a waterworks.
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Affiliation(s)
| | - Hélène Deliniere
- DTU Environment, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Carsten Prasse
- Department of Civil and Environmental, Engineering University of California, Berkeley, CA 94720, United States; Department of Environmental Health and Engineering, Johns Hopkins University, Baltimore, MD 21218, United States
| | - Arnaud Dechesne
- DTU Environment, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
| | - Barth F Smets
- DTU Environment, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark
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2
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Zhang Y, Tay JH. Alternated phenol and trichloroethylene biodegradation in an aerobic granular sludge reactor. Biochem Eng J 2016. [DOI: 10.1016/j.bej.2015.10.026] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Shukla AK, Upadhyay SN, Dubey SK. Current trends in trichloroethylene biodegradation: a review. Crit Rev Biotechnol 2012; 34:101-14. [PMID: 23057686 DOI: 10.3109/07388551.2012.727080] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Over the past few years biodegradation of trichloroethylene (TCE) using different microorganisms has been investigated by several researchers. In this review article, an attempt has been made to present a critical summary of the recent results related to two major processes--reductive dechlorination and aerobic co-metabolism used for TCE biodegradation. It has been shown that mainly Clostridium sp. DC-1, KYT-1, Dehalobacter, Dehalococcoides, Desulfuromonas, Desulfitobacterium, Propionibacterium sp. HK-1, and Sulfurospirillum bacterial communities are responsible for the reductive dechlorination of TCE. Efficacy of bacterial communities like Nitrosomonas, Pseudomonas, Rhodococcus, and Xanthobacter sp. etc. for TCE biodegradation under aerobic conditions has also been examined. Mixed cultures of diazotrophs and methanotrophs have been used for TCE degradation in batch and continuous cultures (biofilter) under aerobic conditions. In addition, some fungi (Trametes versicolor, Phanerochaete chrysosporium ME-446) and Actinomycetes have also been used for aerobic biodegradation of TCE. The available information on kinetics of biofiltration of TCE and its degradation end-products such as CO2 are discussed along with the available results on the diversity of bacterial community obtained using molecular biological approaches. It has emerged that there is a need to use metabolic engineering and molecular biological tools more intensively to improve the robustness of TCE degrading microbial species and assess their diversity.
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Affiliation(s)
- Awadhesh Kumar Shukla
- Department of Botany, Faculty of Science, Banaras Hindu University , Varanasi , India and
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Sun AK, Wood TK. Trichloroethylene mineralization in a fixed-film bioreactor using a pure culture expressing constitutively toluene ortho -monooxygenase. Biotechnol Bioeng 2012; 55:674-85. [PMID: 18636577 DOI: 10.1002/(sici)1097-0290(19970820)55:4<674::aid-bit9>3.0.co;2-e] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
An aerobic, single-pass, fixed-film bioreactor was designed for the continuous degradation and mineralization of gas-phase trichloroethylene (TCE). A pure culture of Burkholderia cepacia PR1(23)(TOM(23C)), a Tn5transposon mutant of B. cepacia G4 that constitutively expresses the TCE-degrading enzyme, toluene ortho-monooxygenase (TOM), was immobilized on sintered glass (SIRANtrade mark carriers) and activated carbon. The inert open-pore structures of the sintered glass and the strongly, TCE-absorbing activated carbon provide a large surface area for biofilm development (2-8 mg total cellular protein/mL carrier with glucose minimal medium that lacks chloride ions). At gas-phase TCE concentrations ranging from 0.04 to 2.42 mg/L of air and 0.1 L/min of air flow, initial maximum TCE degradation rates of 0.007-0.715 nmol/(min mg protein) (equivalent to 8.6-392.3 mg TCE/L of reactor/day) were obtained. Using chloride ion generation as the indicator of TCE mineralization, the bioreactor with activated carbon mineralized an average of 6.9-10.3 mg TCE/L of reactor/day at 0.242 mg/L TCE concentration with 0.1 L/min of air flow for 38-40 days. Although these rates of TCE degradation and mineralization are two- to 200-fold higher than reported values, TOM was inactivated in the sintered-glass bioreactor at a rate that increased with increasing TCE concentration (e.g., in approximately 2 days at 0.242 mg/L and <1 day at 2.42 mg/L), although the biofilter could be operated for longer periods at lower TCE concentrations. Using an oxygen probe and phenol as the substrate, the activity of TOM in the effluent cells of the bioreactor was monitored; the loss of TOM activity of the effluent cells corroborated the decrease in the TCE degradation and mineralization rates in the bioreactor. Repeated starving of the cells was found to restore TOM activity in the bioreactor with activated carbon and extended TCE mineralization by approximately 34%. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 55: 674-685, 1997.
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Affiliation(s)
- A K Sun
- Department of Chemical and Biochemical Engineering, University of California, Irvine, Irvine, California 92697-2575; telephone: 714-824-3147; fax: 714-824-2541
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Pfluger AR, Wu WM, Pieja AJ, Wan J, Rostkowski KH, Criddle CS. Selection of Type I and Type II methanotrophic proteobacteria in a fluidized bed reactor under non-sterile conditions. BIORESOURCE TECHNOLOGY 2011; 102:9919-9926. [PMID: 21906939 DOI: 10.1016/j.biortech.2011.08.054] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2011] [Revised: 08/11/2011] [Accepted: 08/12/2011] [Indexed: 05/31/2023]
Abstract
Type II methanotrophs produce polyhydroxybutyrate (PHB), while Type I methanotrophs do not. A laboratory-scale fluidized bed reactor was initially inoculated with a Type II Methylocystis-like dominated culture. At elevated levels of dissolved oxygen (DO, 9 mg/L), pH of 6.2-6.5 with nitrate as the N-source, a Methylobacter-like Type I methanotroph became dominant within the biofilms which did not produce PHB. A shift to biofilms capable of PHB production was achieved by re-inoculating with Type II Methylosinus culture, providing dissolved N(2) as the N-source, and maintaining a low influent DO (2.0mg/L). The resulting biofilms contained both Types I and II methanotrophs. Batch tests indicated that biofilm samples grown with N(2) became dominated by Type II methanotrophs and produced PHB. Enrichments with nitrate or ammonium were dominated by Type I methanotrophs without PHB production capability. The key selection factors favoring Type II were N(2) as N-source and low DO.
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Affiliation(s)
- Andrew R Pfluger
- Department of Geography and Environmental Engineering, United States Military Academy, 745 Brewerton Road, West Point, NY 10996-1602, USA
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Chee GJ. Biodegradation analyses of trichloroethylene (TCE) by bacteria and its use for biosensing of TCE. Talanta 2011; 85:1778-82. [DOI: 10.1016/j.talanta.2011.07.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Revised: 07/01/2011] [Accepted: 07/01/2011] [Indexed: 11/30/2022]
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Van Hylckama VJ, De Koning W, Janssen DB. Effect of Chlorinated Ethene Conversion on Viability and Activity of Methylosinus trichosporium OB3b. Appl Environ Microbiol 2010; 63:4961-4. [PMID: 16535757 PMCID: PMC1389313 DOI: 10.1128/aem.63.12.4961-4964.1997] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The effect of transformation of chlorinated ethenes on the cell viability of Methylosinus trichosporium OB3b was investigated. A comparison of the loss of viability with the decrease in transformation rates showed that for the monooxygenase-mediated transformation of all chlorinated ethenes except vinyl chloride the decrease in cell viability was the predominant toxic effect.
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Jiang H, Chen Y, Jiang P, Zhang C, Smith TJ, Murrell JC, Xing XH. Methanotrophs: Multifunctional bacteria with promising applications in environmental bioengineering. Biochem Eng J 2010. [DOI: 10.1016/j.bej.2010.01.003] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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9
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Ponza S, Parkpian P, Polprasert C, Shrestha RP, Jugsujinda A. Removal of trichloroethylene (TCE) contaminated soil using a two-stage anaerobic-aerobic composting technique. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2010; 45:549-559. [PMID: 20390902 DOI: 10.1080/10934521003595233] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The effect of organic carbon addition on remediation of trichloroethylene (TCE) contaminated clay soil was investigated using a two stage anaerobic-aerobic composting system. TCE removal rate and processes involved were determined. Uncontaminated clay soil was treated with composting materials (dried cow manure, rice husk and cane molasses) to represent carbon based treatments (5%, 10% and 20% OC). All treatments were spiked with TCE at 1,000 mg TCE/kg DW and incubated under anaerobic and mesophillic condition (35 degrees C) for 8 weeks followed by continuous aerobic condition for another 6 weeks. TCE dissipation, its metabolites and biogas composition were measured throughout the experimental period. Results show that TCE degradation depended upon the amount of organic carbon (OC) contained within the composting treatments/matrices. The highest TCE removal percentage (97%) and rate (75.06 micro Mole/kg DW/day) were obtained from a treatment of 10% OC composting matrices as compared to 87% and 27.75 micro Mole/kg DW/day for 20% OC, and 83% and 38.08 micro Mole/kg DW/day for soil control treatment. TCE removal rate was first order reaction kinetics. Highest degradation rate constant (k(1) = 0.035 day(- 1)) was also obtained from the 10% OC treatment, followed by 20% OC (k(1) = 0.026 day(- 1)) and 5% OC or soil control treatment (k(1) = 0.023 day(- 1)). The half-life was 20, 27 and 30 days, respectively. The overall results suggest that sequential two stages anaerobic-aerobic composting technique has potential for remediation of TCE in heavy texture soil, providing that easily biodegradable source of organic carbon is present.
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Affiliation(s)
- Supat Ponza
- School of Environmental, Resources and Development, Asian Institute of Technology, Pathumthani, Thailand
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10
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Production of soluble methane monooxygenase during growth of Methylosinus trichosporium on methanol. J Biotechnol 2009; 139:78-83. [DOI: 10.1016/j.jbiotec.2008.09.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2008] [Revised: 09/18/2008] [Accepted: 09/23/2008] [Indexed: 11/21/2022]
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11
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Use of gene probes to assess the impact and effectiveness of aerobic in situ bioremediation of TCE. Arch Microbiol 2008; 191:221-32. [DOI: 10.1007/s00203-008-0445-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2008] [Revised: 09/26/2008] [Accepted: 10/20/2008] [Indexed: 10/21/2022]
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12
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Yu Y, Ramsay JA, Ramsay BA. On-line estimation of dissolved methane concentration during methanotrophic fermentations. Biotechnol Bioeng 2006; 95:788-93. [PMID: 16850500 DOI: 10.1002/bit.21050] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Knowledge of the aqueous phase methane concentration is critical to understanding and controlling process kinetics in methanotrophic bioreactors. Unfortunately since no dissolved methane probe is commercially available, this data must be obtained off-line by the time-consuming gas-liquid partition method. In this study we demonstrate how knowledge of the reactor's k(L)a for oxygen combined with gas phase methane analysis can be used to continuously estimate the aqueous phase concentration of dissolved methane. The on-line estimation was verified in two reactor systems with greatly different values of k (L)a. In both systems the measured and calculated dissolved methane concentrations were in good agreement although dissolved methane was underestimated in both cases. The utility of this methodology was demonstrated by revealing a possible metabolic bottleneck in the model system.
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Affiliation(s)
- Yinghao Yu
- Department of Chemical Engineering, Queen's University, Kingston, Ontario, Canada
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13
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Rust CM, Aelion CM, Flora JRV. Laboratory sand column study of encapsulated buffer release for potential in situ pH control. JOURNAL OF CONTAMINANT HYDROLOGY 2002; 54:81-98. [PMID: 11858196 DOI: 10.1016/s0169-7722(01)00142-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Encapsulation technology is being investigated as a method for controlling pH in situ at contaminated groundwater sites where pH may limit remediation of organic contaminants. This study examined the effectiveness of using KH2PO4 buffer encapsulated in a pH-sensitive coating to neutralize pH in laboratory sand columns (1.5-1) under a simulated groundwater flow rate and characterized the pattern of capsule release in the flow-through system. Denitrification was used in the columns to increase the pH of the pore water. Each of three columns was equipped with three miniature mesh wells to allow contact of the buffer with column pore water, but capsules (15 g) were inserted into only one column (amended). The two other columns served as amendment (no buffer) and abiotic (no denitrification) controls. Oxidation-reduction potential, dissolved organic and inorganic carbon, NH4+, NO3- +NO2-, PO(4)3-, and pH were measured in the influent, two side ports, and effluent of the columns over time. Near complete conversion of 80 mg N/1 of nitrate and 152 mg/l of ethanol per day resulted in a mean pH increase from 6.2 to 8.2 in the amendment control column. The amended column maintained the target pH of 7.0 +/- 0.2 for 4 weeks until the capsules began to be depleted, after which time the pH slowly started to increase. The capsules exhibited pulses of buffer release, and were effectively dissolved after 7.5 weeks of operation. Base-neutralizing capacity contributed by the encapsulated buffer over the entire study period, calculated as cation equivalents, was 120 mM compared to 8 mM without buffer. This study demonstrates the potential for this technology to mediate pH changes and provides the framework for future studies in the laboratory and in the field, in which pH is controlled in order to enhance organic contaminant remediation by pH-sensitive systems.
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Affiliation(s)
- Christine M Rust
- Department of Environmental Health Sciences, University of South Carolina, Columbia 29208, USA
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14
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Bioremediation of compounds hazardous to health and the environment: An overview. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s0079-6352(02)80005-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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15
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Collins C, Laturnus F, Nepovim A. Remediation of BTEX and trichloroethene. Current knowledge with special emphasis on phytoremediation. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2002; 9:86-94. [PMID: 11885421 DOI: 10.1007/bf02987319] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The widespread use of industrial chemicals in our highly industrialized society has often caused contamination of large terrestrial and marine areas due to the deliberate and accidental release of organic pollutants into the soil and groundwater. In this review, environmental problems arising from the use of chlorinated solvents and BTEX compounds are described, and an overview about active management strategies for remediation with special emphasis on phytoremediation are presented to achieve a reduction of the total mass of chlorinated solvents and BTEX compounds in contaminated areas. Phytoremediation has been proposed as an efficient, low-cost remediation technique to restore areas contaminated with chlorinated solvents and BTEX compounds. The feasibility of phytoremediation as a remediation tool for these compounds is discussed with particular reference to the uptake and metabolism of these compounds, and a future perspective on the use of phytoremediation for the removal of chlorinated solvents and BTEX compounds is given.
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Affiliation(s)
- Chris Collins
- Department of Environmental Science and Technology, Imperial College of Science Technology and Medicine, Prince Consort Road, London, SW7 2BP, UK.
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van Hylckama Vlieg JE, Janssen DB. Formation and detoxification of reactive intermediates in the metabolism of chlorinated ethenes. J Biotechnol 2001; 85:81-102. [PMID: 11165358 DOI: 10.1016/s0168-1656(00)00364-3] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Short-chain halogenated aliphatics, such as chlorinated ethenes, constitute a large group of priority pollutants. This paper gives an overview on the chemical and physical properties of chlorinated aliphatics that are critical in determining their toxicological characteristics and recalcitrance to biodegradation. The toxic effects and principle metabolic pathways of halogenated ethenes in mammals are briefly discussed. Furthermore, the bacterial degradation of halogenated compounds is reviewed and it is described how product toxicity may explain why most chlorinated ethenes are only degraded cometabolically under aerobic conditions. The cometabolic degradation of chlorinated ethenes by oxygenase-producing microorganisms has been extensively studied. The physiology and bioremediation potential of methanotrophs has been well characterized and an overview of the available data on these organisms is presented. The sensitivity of methanotrophs to product toxicity is a major limitation for the transformation of chlorinated ethenes by these organisms. Most toxic effects arise from the inability to detoxify the reactive chlorinated epoxyethanes occurring as primary metabolites. Therefore, the last part of this review focuses on the metabolic reactions and enzymes that are involved in the detoxification of epoxides in mammals. A key role is played by glutathione S-transferases. Furthermore, an overview is presented on the current knowledge about bacterial enzymes involved in the metabolism of epoxides. Such enzymes might be useful for detoxifying chlorinated ethene epoxides and an example of a glutathione S-transferase with activity for dichloroepoxyethane is highlighted.
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Affiliation(s)
- J E van Hylckama Vlieg
- Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, NL-9747 AG, Groningen, The Netherlands
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Sullivan JP, Dickinson D, Chase HA. Methanotrophs, Methylosinus trichosporium OB3b, sMMO, and their application to bioremediation. Crit Rev Microbiol 1999; 24:335-73. [PMID: 9887367 DOI: 10.1080/10408419891294217] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
One of the most problematic groups of the USEPA and EU priority pollutants are the halogenated organic compounds. These substances have a wide range of industrial applications, such as solvents and cleaners. Inadequate disposal techniques and accidental spillages have led to their detection in soil, groundwater, and river sediments. Persistence of these compounds in the environment has resulted from low levels of biodegradation due to chemical structural features that preclude or retard biological attack. Research has indicated the idea that treatment systems based on methanotrophic co-metabolic transformation may be a cost-effective and efficient alternative to physical methods because of the potential for high transformation rates, the possibility of complete compound degradation without the formation of toxic metabolites, applicability to a broad spectrum of compounds, and the use of a widely available and inexpensive growth substrate. A substantial amount of work concerning methanotrophic cometabolic transformations has been carried out using the soluble form of methane monooxygenase (sMMO) from the obligate methanotroph Methylosinus trichosporium OB3b. This NADH-dependent monooxygenase is derepressed when cells are grown under copper stress. sMMO has a wider specificity than the particulate form. sMMO has been shown to degrade trichloroethylene (TCE) at a rate of at least one order of magnitude faster than obtained with other mixed and pure cultures, suggesting it has a wider application to bioremediation. Furthermore, sMMO catalyzes an unusually wide range of oxidation reactions, including the hydroxylation of alkanes, epoxidation of alkenes, ethers, halogenated methanes, cyclic and aromatic compounds including compounds, that are resistant to degradation in the environment. However, the practical application of methantrophs and Methylosinus trichosporium OB3b to the treatment of chlorinated organics has met with mixed success. Although oxidation rates are rapid, compound oxidation with M. trichosporium OB3b is difficult. This fastidious organism grows relatively slowly, which limits the speed with which sMMO expressing biomass can be generated. Furthermore, product toxicity toward the cell, affecting the stability of the enzyme when transforming certain compounds has been observed, for example, by the products of 1,2,3 trichlorobenzene hydroxylation (2,3,4- and 3,4,5-trichlorophenol) and of TCE degradation (chloral hydrate). Because of this toxicity and the inability of sMMO to further oxidize its own hydroxylation products, the ability of methane monoxygenase to carry out the monooxygenation of a wide variety of substituted aromatics and polyaromatics cannot be fully exploited in M. trichosporium OB3b. Many of these problems could be overcome by the use of either a mixed downstream heterotrophic population of organisms that could accommodate the products of hydroxylation or to express sMMO in an organism that could metabolize the products of hydroxylation. The latter of these two approaches would have several advantages. The main benefit would be the removal of the need for methane, which is required to induce sMMO in M. trichosporium OB3b, and supply carbon and energy to the cells that continuously oxidise the target compound, but also acts as a competitive inhibitor of sMMO. Instead, the recombinant could utilize the products of sMMO-mediated hydroxylation as a carbon source.
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Affiliation(s)
- J P Sullivan
- Biology Department, Imperial College of Science, Technology and Medicine, London.
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Sukesan S, Watwood ME. Effects of hydrocarbon enrichment on trichloroethylene biodegradation and microbial populations in finished compost. J Appl Microbiol 1998; 85:635-42. [PMID: 9812376 DOI: 10.1111/j.1365-2672.1998.00565.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
This study focused on the capacity of finished compost, often used as packing material in biofiltration units, to support microbial biodegradation of trichloroethylene (TCE). Finished compost was enriched with methane or propane (10% head space) to stimulate cometabolic biodegradation of gaseous TCE. Successful hydrocarbon enrichment, as indicated by rapid depletion of hydrocarbon gas and measurable growth of hydrocarbon-utilizing micro-organisms, occurred within a week. Within batch reactor flasks, approximately 75% of head space TCE (1-40 ppmv) was rapidly sorbed onto compost material. Up to 99% of the remaining head space TCE was removed via biodegradation in compost enriched with either hydrocarbon. Hydrocarbon enrichment with methane or propane corresponded to 10-fold increases in methanotrophic or propanotrophic populations, respectively. Based on growth assessment under different nutritional regimes, there appeared to be complex metabolic interactions within the microbial community in enriched compost. Five separate bacterial cultures were derived from the hydrocarbon-enriched compost and assayed for the ability to degrade TCE.
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Affiliation(s)
- S Sukesan
- Department of Biological Sciences, Idaho State University, Pocatello 83209, USA
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Sun AK, Hong J, Wood TK. Modeling trichloroethylene degradation by a recombinant pseudomonad expressing toluene ortho-monooxygenase in a fixed-film bioreactor. Biotechnol Bioeng 1998; 59:40-51. [PMID: 10099312 DOI: 10.1002/(sici)1097-0290(19980705)59:1<40::aid-bit6>3.0.co;2-t] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Burkholderia cepacia PR123(TOM23C), expressing constitutively the TCE-degrading enzyme toluene ortho-monooxygenase (Tom), was immobilized on SIRANtrade mark glass beads in a biofilter for the degradation and mineralization of gas-phase trichloroethylene (TCE). To interpret the experimental results, a mathematical model has been developed which includes axial dispersion, convection, film mass-transfer, and biodegradation coupled with deactivation of the TCE-degrading enzyme. Parameters used for numerical simulation were determined from either independent experiments or values reported in the literature. The model was compared with the experimental data, and there was good agreement between the predicted and measured TCE breakthrough curves. The simulations indicated that TCE degradation in the biofilter was not limited by mass transfer of TCE or oxygen from the gas phase to the liquid/biofilm phase (biodegradation limits), and predicts that improving the specific TCE degradation rates of bacteria will not significantly enhance long-term biofilter performance. The most important factors for prolonging the performance of biofilter are increasing the amount of active biomass and the transformation capacity (enhancing resistance to TCE metabolism). Copyright 1998 John Wiley & Sons, Inc.
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Affiliation(s)
- AK Sun
- Department of Chemical and Biochemical Engineering, University of California, Irvine, Irvine, California 92697-2575, USA
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Smith LH, McCarty PL. Laboratory evaluation of a two-stage treatment system for TCE cometabolism by a methane-oxidizing mixed culture. Biotechnol Bioeng 1997; 55:650-9. [DOI: 10.1002/(sici)1097-0290(19970820)55:4<650::aid-bit7>3.0.co;2-g] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Anderson JE, McCarty PL. Transformation yields of chlorinated ethenes by a methanotrophic mixed culture expressing particulate methane monooxygenase. Appl Environ Microbiol 1997; 63:687-93. [PMID: 9023946 PMCID: PMC168358 DOI: 10.1128/aem.63.2.687-693.1997] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Transformation yields for the aerobic cometabolic degradation of five chlorinated ethenes were determined by using a methanotrophic mixed culture expressing particulate methane monooxygenase (pMMO). Transformation yields (expressed as moles of chlorinated ethene degraded per mole of methane consumed) were 0.57, 0.25, 0.058, 0.0019, and 0.00022 for trans-1,2-dichloroethylene (t-DCE), vinyl chloride (VC), cis-1,2-dichloroethylene (c-DCE), trichloroethylene (TCE), and 1,1-dichloroethylene (1,1-DCE), respectively. Degradation of t-DCE and VC was observed only in the presence of formate or methane, sources of reducing energy necessary for cometabolism. The t-DCE and VC transformation yields represented 35 and 15%, respectively, of the theoretical maximum yields, based on reducing-energy availability from methane dissimilation to carbon dioxide, exclusive of all other processes that require reducing energy. The yields for t-DCE and VC were 20 times greater than the yields reported by others for cells expressing soluble methane monooxygenase (sMMO). Transformation yields for c-DCE, TCE, and 1,1-DCE were similar to or less than those for cultures expressing sMMO. Although methanotrophic biotreatment systems have typically been designed to incorporate cultures expressing sMMO, these results suggest that pMMO expression may be highly advantageous for degradation of t-DCE or VC. It may also be much easier to maintain pMMO expression in treatment systems, because pMMO is expressed by all methanotrophs whereas sMMO is expressed only by type II methanotrophs under copper-limited conditions.
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Affiliation(s)
- J E Anderson
- Department of Civil Engineering, Stanford University, California 94305-4020, USA
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22
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Stability of toluene oxidation by Pseudomonas putida under nutrient deprivation. Appl Microbiol Biotechnol 1996. [DOI: 10.1007/bf00166234] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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23
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Abstract
Methane-utilizing bacteria (methanotrophs) are a diverse group of gram-negative bacteria that are related to other members of the Proteobacteria. These bacteria are classified into three groups based on the pathways used for assimilation of formaldehyde, the major source of cell carbon, and other physiological and morphological features. The type I and type X methanotrophs are found within the gamma subdivision of the Proteobacteria and employ the ribulose monophosphate pathway for formaldehyde assimilation, whereas type II methanotrophs, which employ the serine pathway for formaldehyde assimilation, form a coherent cluster within the beta subdivision of the Proteobacteria. Methanotrophic bacteria are ubiquitous. The growth of type II bacteria appears to be favored in environments that contain relatively high levels of methane, low levels of dissolved oxygen, and limiting concentrations of combined nitrogen and/or copper. Type I methanotrophs appear to be dominant in environments in which methane is limiting and combined nitrogen and copper levels are relatively high. These bacteria serve as biofilters for the oxidation of methane produced in anaerobic environments, and when oxygen is present in soils, atmospheric methane is oxidized. Their activities in nature are greatly influenced by agricultural practices and other human activities. Recent evidence indicates that naturally occurring, uncultured methanotrophs represent new genera. Methanotrophs that are capable of oxidizing methane at atmospheric levels exhibit methane oxidation kinetics different from those of methanotrophs available in pure cultures. A limited number of methanotrophs have the genetic capacity to synthesize a soluble methane monooxygenase which catalyzes the rapid oxidation of environmental pollutants including trichloroethylene.
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Affiliation(s)
- R S Hanson
- Department of Microbiology, University of Minnesota, Minneapolis 55455, USA.
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24
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Heald SC, Jenkins RO. Expression and substrate specificity of the toluene dioxygenase of Pseudomonas putida NCIMB 11767. Appl Microbiol Biotechnol 1996; 45:56-62. [PMID: 8920179 DOI: 10.1007/s002530050649] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Pseudomonas putida NCIMB 11767 oxidized phenol, monochlorophenols, several dichlorophenols and a range of alkylbenzenes (C1-C6) via an inducible toluene dioxygenase enzyme system. Biphenyl and naphthalene were also oxidized by this enzyme. Growth on toluene and phenol induced the meta-ring-fission enzyme, catechol 2,3-oxygenase, whereas growth on benzoate, which did not require expression of toluene dioxygenase, induced the ortho-ring-cleavage enzyme, catechol 1,2-oxygenase. Monochlorobenzoate isomers and 2,3,5-trichlorophenol were gratuitous inducers of toluene dioxygenase, whereas 3,4-dichlorophenol was a fortuitous oxidation substrate of the enzyme. The organism also grew on 2,4- and 2,5-dichloro isomers of both phenol and benzoate, on 2,3,4-trichlorophenol and on 1-phenylheptane. During growth on toluene in nitrogen-limited chemostat culture, expression of both toluene dioxygenase and catechol 2,3-oxygenase was positively correlated with increase in specific growth rate (0.11-0.74 h-1), whereas the biomass yield coefficient decreased. At optimal dilution rates, the predicted performance of a 1-m3 bioreactor supplied with 1 g nitrogen l-1 for removal of toluene was 57 g day-1 and for removal of trichloroethylene was 3.4 g day-1. The work highlights the oxidative versatility of this bacterium with respect to substituted hydrocarbons and shows how growth rate influences the production of competent cells for potential use as bioremediation catalysts.
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Affiliation(s)
- S C Heald
- Department of Biological Sciences, De Montfort University, Scraptoft, Leicester, UK
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25
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Klečka GM, McDaniel SG, Wilson PS, Carpenter CL, Clark JE, Thomas A, Spain JC. Field evaluation of a granular activated carbon fluid-bed bioreactor for treatment of chlorobenzene in groundwater. ACTA ACUST UNITED AC 1996. [DOI: 10.1002/ep.670150212] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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26
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Hecht V, Brebbermann D, Bremer P, Deckwer WD. Cometabolic degradation of trichloroethylene in a bubble column bioscrubber. Biotechnol Bioeng 1995; 47:461-9. [DOI: 10.1002/bit.260470407] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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27
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Chang HL, Alvarez-Cohen L. Transformation capacities of chlorinated organics by mixed cultures enriched on methane, propane, toluene, or phenol. Biotechnol Bioeng 1995; 45:440-9. [DOI: 10.1002/bit.260450509] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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28
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Uchiyama H, Oguri K, Nishibayashi M, Kokufuta E, Yagi O. Trichloroethylene degradation by cells of a methane-utilizing bacterium, Methylocystis sp. M, immobilized in calcium alginate. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/0922-338x(95)94756-h] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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29
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Fetzner S, Lingens F. Bacterial dehalogenases: biochemistry, genetics, and biotechnological applications. Microbiol Rev 1994; 58:641-85. [PMID: 7854251 PMCID: PMC372986 DOI: 10.1128/mr.58.4.641-685.1994] [Citation(s) in RCA: 148] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
This review is a survey of bacterial dehalogenases that catalyze the cleavage of halogen substituents from haloaromatics, haloalkanes, haloalcohols, and haloalkanoic acids. Concerning the enzymatic cleavage of the carbon-halogen bond, seven mechanisms of dehalogenation are known, namely, reductive, oxygenolytic, hydrolytic, and thiolytic dehalogenation; intramolecular nucleophilic displacement; dehydrohalogenation; and hydration. Spontaneous dehalogenation reactions may occur as a result of chemical decomposition of unstable primary products of an unassociated enzyme reaction, and fortuitous dehalogenation can result from the action of broad-specificity enzymes converting halogenated analogs of their natural substrate. Reductive dehalogenation either is catalyzed by a specific dehalogenase or may be mediated by free or enzyme-bound transition metal cofactors (porphyrins, corrins). Desulfomonile tiedjei DCB-1 couples energy conservation to a reductive dechlorination reaction. The biochemistry and genetics of oxygenolytic and hydrolytic haloaromatic dehalogenases are discussed. Concerning the haloalkanes, oxygenases, glutathione S-transferases, halidohydrolases, and dehydrohalogenases are involved in the dehalogenation of different haloalkane compounds. The epoxide-forming halohydrin hydrogen halide lyases form a distinct class of dehalogenases. The dehalogenation of alpha-halosubstituted alkanoic acids is catalyzed by halidohydrolases, which, according to their substrate and inhibitor specificity and mode of product formation, are placed into distinct mechanistic groups. beta-Halosubstituted alkanoic acids are dehalogenated by halidohydrolases acting on the coenzyme A ester of the beta-haloalkanoic acid. Microbial systems offer a versatile potential for biotechnological applications. Because of their enantiomer selectivity, some dehalogenases are used as industrial biocatalysts for the synthesis of chiral compounds. The application of dehalogenases or bacterial strains in environmental protection technologies is discussed in detail.
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Affiliation(s)
- S Fetzner
- Institut für Mikrobiologie der Universität Hohenheim, Stuttgart, Germany
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30
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Heald S, Jenkins RO. Trichloroethylene removal and oxidation toxicity mediated by toluene dioxygenase of Pseudomonas putida. Appl Environ Microbiol 1994; 60:4634-7. [PMID: 7811103 PMCID: PMC202037 DOI: 10.1128/aem.60.12.4634-4637.1994] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Whole cells of Pseudomonas putida containing toluene dioxygenase were able to remove all detectable trichloroethylene (TCE) from assay mixtures. The capacity of cells to remove TCE was 77 microM/mg of protein with an initial rate of removal of 5.2 nmol/min/ng of protein. TCE oxidation resulted in a decrease in the growth rate of cultures and caused rapid cell death. Addition of dithiothreitol to assay mixtures increased the TCE removal capacity of cells by up to 67% but did not prevent TCE-mediated cell death. TCE induced toluene degradation by whole cells to a rate approximately 40% of that induced by toluene itself.
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Affiliation(s)
- S Heald
- Department of Applied Biology and Biotechnology, De Montfort University, Scraptoft, Leicester, United Kingdom
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31
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Uchiyama H, Yagi O, Oguri K, Kokufuta E. Immobilization of trichloroethylene-degrading bacterium, Methylocystis sp. strain M in different matrices. ACTA ACUST UNITED AC 1994. [DOI: 10.1016/0922-338x(94)90319-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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32
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McKAY DANIELJ, MORSE JOHNS, HAZEN TERRYC. Biodegradation of Trichloroethylene byAlcaligenes eutrophusJMP134 in a Laboratory Scale Bioreactor. ACTA ACUST UNITED AC 1994. [DOI: 10.1089/hwm.1994.11.491] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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33
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Ensley BD, Kurisko PR. A Gas Lift Bioreactor for Removal of Contaminants from the Vapor Phase. Appl Environ Microbiol 1994; 60:285-90. [PMID: 16349158 PMCID: PMC201301 DOI: 10.1128/aem.60.1.285-290.1994] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The cometabolic degradation of trichloroethylene (TCE) as a vapor by two aromatic-metabolizing pseudomonads was evaluated in an airlift reactor. These microorganisms were able to degrade 90 to 95% of TCE in air at concentrations at the reactor inlet of 300 to 4,000 μg/liter. Although exposure of the cells to high inlet concentrations of TCE (4 mg/liter) caused a decline in enzyme-specific activity and TCE removal efficiency, this loss in activity could be prevented or delayed by increasing the rate of cosubstrate addition. Under the appropriate operating conditions, the microorganisms were able to degrade even high concentrations of TCE and activity of the cells in the reactor could be maintained for periods of at least 2 weeks.
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Affiliation(s)
- B D Ensley
- Envirogen Inc., Princeton Research Center, Lawrenceville, New Jersey 08648
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34
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Dolfing J, van den Wijngaard AJ, Janssen DB. Microbiological aspects of the removal of chlorinated hydrocarbons from air. Biodegradation 1993; 4:261-82. [PMID: 7764923 DOI: 10.1007/bf00695974] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Chlorinated hydrocarbons are widely used synthetic chemicals that are frequently present in industrial emissions. Bacterial degradation has been demonstrated for several components of this class of compounds. Structural features that affect the degradability include the number of chlorine atoms and the presence of oxygen substituents. Biological removal from waste streams of compounds that serve as a growth substrate can relatively easily be achieved. Substrates with more chlorine substituents can be converted co-metabolically by oxidative routes. The microbiological principles that influence the biodegradability of chlorinated hydrocarbons are described. A number of factors that will determine the performance of microorganisms in systems for waste gas treatment is discussed. Pilot plant evaluations, including economics, of a biological trickling filter for the treatment of dichloromethane containing waste gas indicate that at least for this compound biological treatment is cost effective.
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Affiliation(s)
- J Dolfing
- Department of Biochemistry, University of Groningen, The Netherlands
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35
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Providenti MA, Lee H, Trevors JT. Selected factors limiting the microbial degradation of recalcitrant compounds. ACTA ACUST UNITED AC 1993. [DOI: 10.1007/bf01569669] [Citation(s) in RCA: 84] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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36
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Fennell DE, Nelson YM, Underhill SE, White TE, Jewell WJ. TCE degradation in a methanotrophic attached-film bioreactor. Biotechnol Bioeng 1993; 42:859-72. [DOI: 10.1002/bit.260420711] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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37
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Lackey LW, Phelps TJ, Bienkowski PR, White DC. Biodegradation of chlorinated aliphatic hydrocarbon mixtures in a single-pass packed-bed reactor. Appl Biochem Biotechnol 1993; 39-40:701-13. [PMID: 8323270 DOI: 10.1007/bf02919029] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Aliphatic chlorinated compounds, such as trichloroethylene (TCE) and tetrachloroethylene (PCE), are major contaminants of ground water. A single-pass packed-bed bioreactor was utilized to study the biodegradation of organic waste mixtures consisting of PCE, TCE, and other short-chain chlorinated organics. The bioreactor consisted of two 1960-mL glass columns joined in a series. One column was packed with sand containing a microbial consortia enriched from a contaminated site. The other column provided a reservoir for oxygen and a carbon source of methane/propane that was recirculated through the reactor. Sampling was accomplished by both direct headspace and liquid effluent concentration analyses. The reactor was operated in a single-pass mode. Greater than 99% degradation of trichloroethylene, approaching drinking water standards, was observed when the bioreactor residence time ranged from 1.9 to 3.2 d. Typically, when the reactor was pulse-fed with methane, propane, and air, 1 mol of TCE was degraded/110 mol of substrate utilized. Perturbation studies were performed to characterize reactor behavior. The system's degradation behavior was affected by providing different carbon sources, a pulse feeding regime, supplementing microbial biomass, and by altering flow rates.
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Affiliation(s)
- L W Lackey
- Center for the Environmental Biotechnology, University of Tennessee-Knoxville 37996-2200
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38
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Korde VM, Phelps TJ, Bienkowski PR, White DC. Biodegradation of chlorinated aliphatics and aromatic compounds in total-recycle expanded-bed biofilm reactors. Appl Biochem Biotechnol 1993; 39-40:631-41. [PMID: 8323267 DOI: 10.1007/bf02919024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Ground-water contamination by chlorinated aliphatic compounds is a major cause for concern because of their toxicity. This study examined the biodegradation of trichloroethylene and aromatic compounds by microbial consortia enriched from contaminated subsurface sediments. The consortia were capable of utilizing methane and propane as sources of carbon and energy. Two continuously recycled expanded-bed bioreactors were inoculated with (1) the subsurface consortium, and (2) P. fluorescence, P. putida (strains pRB1401 and pWWO), and M. trichosporium OB3b. An uninoculated reactor containing 0.2% sodium azide and 0.5% formalin served as the control. Methane (5% v/v) and propane (3% v/v) were maintained by batch feeding through the course of the experiment. Greater than 97% degradation of trichloroethylene was observed over a period of 12 d. More than 99% of benzene, toluene, and xylene were degraded within the first 7 d. Dissolved oxygen levels were measured and found to be in the range 4.9-6.5 mg/L throughout the experiments.
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Affiliation(s)
- V M Korde
- Center for Environmental Biotechnology, University of Tennessee, Knoxville 37932-2567
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39
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Monitoring microbiol adhesion and biofilm formation by attenuated total reflection/Fourier transform infrared spectroscopy. J Microbiol Methods 1993. [DOI: 10.1016/0167-7012(93)90047-l] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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40
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Fennell DE, Underhill SE, Jewell WJ. Methanotrophic attached-film reactor development and biofilm characteristics. Biotechnol Bioeng 1992; 40:1218-32. [DOI: 10.1002/bit.260401012] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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41
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Trichloroethylene degradation by immobilized restingcells ofMethylocystis sp. M in a gas-solid bioreactor. Biotechnol Lett 1992. [DOI: 10.1007/bf01023952] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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42
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Fathepure BZ, Vogel TM. Complete degradation of polychlorinated hydrocarbons by a two-stage biofilm reactor. Appl Environ Microbiol 1991; 57:3418-22. [PMID: 1785918 PMCID: PMC183990 DOI: 10.1128/aem.57.12.3418-3422.1991] [Citation(s) in RCA: 107] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
A two-stage anaerobic-aerobic biofilm reactor successfully degraded a mixture of chlorinated organic compounds to water-soluble metabolic intermediates and carbon dioxide. Reductive dechlorination of hexachlorobenzene (HCB), tetrachloroethylene (PCE), and chloroform (CF) occurred on all tested primary carbon sources such as glucose, methanol, and acetate. However, the extent of dechlorination was maximum when the anaerobic biofilm column was fed acetate as a primary carbon source. HCB, PCE, and CF were dechlorinated to the levels of tri- and dichlorinated products (99, 80, and 32%, respectively) with acetate in the feed. This is important, since these less-chlorinated compounds can be metabolized by the aerobic biofilm. The effluent from the anaerobic biofilm column was fed directly into the aerobic column. After both columns, the total amount transformed into nonvolatile intermediates and carbon dioxide was 94, 96, and 83% for [14C]HCB, [14C]trichloroethylene, and [14C]CF, respectively. This research shows the potential application of this novel two-stage bioreactor system for treating groundwaters and industrial effluents composed of highly chlorinated aliphatic and aromatic hydrocarbons.
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Affiliation(s)
- B Z Fathepure
- Department of Civil and Environmental Engineering, Michigan State University, East Lansing 48824
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43
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Folsom BR, Chapman PJ. Performance characterization of a model bioreactor for the biodegradation of trichloroethylene by Pseudomonas cepacia G4. Appl Environ Microbiol 1991; 57:1602-8. [PMID: 1872599 PMCID: PMC183439 DOI: 10.1128/aem.57.6.1602-1608.1991] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Pseudomonas cepacia G4 grown in chemostats with phenol demonstrated constant specific degradation rates for both phenol and trichloroethylene (TCE) over a range of dilution rates. Washout of cells from chemostats was evident at a dilution rate of 0.2 h-1 at 28 degrees C. Increased phenol concentrations in the nutrient feed led to increased biomass production with constant specific degradation rates for both phenol and TCE. The addition of lactate to the phenol feed led to increased biomass production but lowered specific phenol and TCE degradation rates. The maximum potential for TCE degradation was about 1.1 g per day per g of cell protein. Cell growth and degradation kinetic parameters were used in the design of a recirculating bioreactor for TCE degradation. In this reactor, the total amount of TCE degraded increased as either reaction time or biomass was increased. TCE degradation was observed up to 300 microM TCE with no significant decreases in rates. On the average, this reactor was able to degrade 0.7 g of TCE per day per g of cell protein. These results demonstrate the feasibility of TCE bioremediation through the use of bioreactors.
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Affiliation(s)
- B R Folsom
- Environmental Research Laboratory, U.S. Environmental Protection Agency, Gulf Breeze, Florida 32561
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