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Degradation of 2,4,6-Trinitrotoluene (TNT): Involvement of Protocatechuate 3,4-Dioxygenase (P34O) in Buttiauxella sp. S19-1. TOXICS 2021; 9:toxics9100231. [PMID: 34678927 PMCID: PMC8540567 DOI: 10.3390/toxics9100231] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 09/13/2021] [Accepted: 09/17/2021] [Indexed: 11/22/2022]
Abstract
Extensive use and disposal of 2,4,6-trinitrotoluene (TNT), a primary constituent of explosives, pollutes the environment and causes severe damage to human health. Complete mineralization of TNT via bacterial degradation has recently gained research interest as an effective method for the restoration of contaminated sites. Here, screening for TNT degradation by six selected bacteria revealed that Buttiauxella sp. S19-1, possesses the strongest degrading ability. Moreover, BuP34O (a gene encoding for protocatechuate 3,4-dioxygenase—P34O, a key enzyme in the β-ketoadipate pathway) was upregulated during TNT degradation. A knockout of BuP34O in S19-1 to generate S-M1 mutant strain caused a marked reduction in TNT degradation efficiency compared to S19-1. Additionally, the EM1 mutant strain (Escherichia coli DH5α transfected with BuP34O) showed higher degradation efficiency than DH5α. Gas chromatography mass spectrometry (GC-MS) analysis of TNT degradation by S19-1 revealed 4-amino-2,6-dinitrotolune (ADNT) as the intermediate metabolite of TNT. Furthermore, the recombinant protein P34O (rP34O) expressed the activity of 2.46 µmol/min·mg. Our findings present the first report on the involvement of P34O in bacterial degradation of TNT and its metabolites, suggesting that P34O could catalyze downstream reactions in the TNT degradation pathway. In addition, the TNT-degrading ability of S19-1, a Gram-negative marine-derived bacterium, presents enormous potential for restoration of TNT-contaminated seas.
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Lan RS, Smith CA, Hyman MR. Oxidation of Cyclic Ethers by Alkane-Grown Mycobacterium vaccae
JOB5. ACTA ACUST UNITED AC 2013. [DOI: 10.1002/rem.21364] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Bernstein A, Ronen Z. Biodegradation of the Explosives TNT, RDX and HMX. ENVIRONMENTAL SCIENCE AND ENGINEERING 2012. [DOI: 10.1007/978-3-642-23789-8_5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Soils contaminated with explosives: Environmental fate and evaluation of state-of-the-art remediation processes (IUPAC Technical Report). PURE APPL CHEM 2011. [DOI: 10.1351/pac-rep-10-01-05] [Citation(s) in RCA: 111] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
An explosion occurs when a large amount of energy is suddenly released. This energy may come from an over-pressurized steam boiler, from the products of a chemical reaction involving explosive materials, or from a nuclear reaction that is uncontrolled. In order for an explosion to occur, there must be a local accumulation of energy at the site of the explosion, which is suddenly released. This release of energy can be dissipated as blast waves, propulsion of debris, or by the emission of thermal and ionizing radiation. Modern explosives or energetic materials are nitrogen-containing organic compounds with the potential for self-oxidation to small gaseous molecules (N2, H2O, and CO2). Explosives are classified as primary or secondary based on their susceptibility of initiation. Primary explosives are highly susceptible to initiation and are often used to ignite secondary explosives, such as TNT (2,4,6-trinitrotoluene), RDX (1,3,5-trinitroperhydro-1,3,5-triazine), HMX (1,3,5,7-tetranitro-1,3,5,7-tetrazocane), and tetryl (N-methyl-N-2,4,6-tetranitro-aniline).
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Bruns-Nagel D, Breitung J, von Low E, Steinbach K, Gorontzy T, Kahl M, Blotevogel K, Gemsa D. Microbial transformation of 2,4,6-trinitrotoluene in aerobic soil columns. Appl Environ Microbiol 2010; 62:2651-6. [PMID: 16535369 PMCID: PMC1388907 DOI: 10.1128/aem.62.7.2651-2656.1996] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
2,4,6-Trinitrotoluene (TNT)-contaminated soil material of a former TNT production plant was percolated aerobically in soil columns. Nineteen days of percolation with a potassium phosphate buffer supplemented with glucose or glucose plus ammonium sulfate caused an over 90% decline in the amount of extractable nitroaromatics in soils containing 70 to 2,100 mg of TNT per kg (dry weight). In the percolation solution, a complete elimination of TNT was achieved. Mutagenicity and soil toxicity were significantly reduced by the percolation process. 4-N-Acetylamino-2-amino-6-nitrotoluene was generated in soil and percolation fluid as a labile TNT metabolite.
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Fiorella PD, Spain JC. Transformation of 2,4,6-Trinitrotoluene by Pseudomonas pseudoalcaligenes JS52. Appl Environ Microbiol 2010; 63:2007-15. [PMID: 16535610 PMCID: PMC1389165 DOI: 10.1128/aem.63.5.2007-2015.1997] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pseudomonas pseudoalcaligenes JS52 grows on nitrobenzene via partial reduction of the nitro group and enzymatic rearrangement of the resultant hydroxylamine. Cells and cell extracts of nitrobenzene-grown JS52 catalyzed the transient formation of 4-hydroxylamino-2,6-dinitrotoluene (4HADNT), 4-amino-2,6-dinitrotoluene (4ADNT), and four previously unidentified metabolites from 2,4,6-trinitrotoluene (TNT). Two of the novel metabolites were identified by liquid chromatography/mass spectrometry and (sup1)H-nuclear magnetic resonance spectroscopy as 2,4-dihydroxylamino-6-nitrotoluene (DHANT) and 2-hydroxylamino-4-amino-6-nitrotoluene (2HA4ANT). A polar yellow metabolite also accumulated during transformation of TNT by cells and cell extracts. Under anaerobic conditions, extracts of strain JS52 did not catalyze the production of the yellow metabolite or release nitrite from TNT; moreover, DHANT and 2HA4ANT accumulated under anaerobic conditions, which indicated that their further metabolism was oxygen dependent. Small amounts of nitrite were released during transformation of TNT by strain JS52. Sustained transformation of TNT by cells required nitrobenzene, which indicated that TNT transformation does not provide energy. Transformation of TNT catalyzed by enzymes in cell extracts required NADPH. Transformation experiments with (sup14)C-TNT indicated that TNT was not mineralized; however, carbon derived from TNT became associated with cells. Nitrobenzene nitroreductase purified from strain JS52 transformed TNT to DHANT via 4HADNT, which indicated that the nitroreductase could catalyze the first two steps in the transformation of TNT. The unusual ability of the nitrobenzene nitroreductase to catalyze the stoichiometric reduction of aromatic nitro compounds to the corresponding hydroxylamine provides the basis for the novel pathway for metabolism of TNT.
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House AJ, Hyman MR. Effects of gasoline components on MTBE and TBA cometabolism by Mycobacterium austroafricanum JOB5. Biodegradation 2009; 21:525-41. [DOI: 10.1007/s10532-009-9321-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2009] [Accepted: 11/26/2009] [Indexed: 11/28/2022]
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Wu H, Wei C, Wang Y, He Q, Liang S. Degradation of o-chloronitrobenzene as the sole carbon and nitrogen sources by Pseudomonas putida OCNB-1. J Environ Sci (China) 2009; 21:89-95. [PMID: 19402405 DOI: 10.1016/s1001-0742(09)60016-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A bacterial strain that utilized o-chloronitrobenzene (o-CNB) as the sole carbon, nitrogen and energy sources was isolated from an activated sludge collected from an industrial waste treatment plant. It was identified as Pseudomonas putida based on its morphology, physiological, and biochemical characteristics with an automatic biometrical system and the 16S rRNA sequence analysis. Microcosm study showed that the biodegradation of o-CNB was optimized at culture medium pH 8.0 and 32 degrees C. At these conditions, the strain degraded 85% of o-CNB at a starting concentration of 1.1 mmol/L in 42 h. o-Chloroaniline was identified as the major metabolite with high performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS). The study showed that o-CNB degradation by Pseudomonas putida OCNB-1 was initiated by aniline dioxyenase, nitrobenzene reductase and catechol-1,2-dioxygenase.
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Affiliation(s)
- Haizhen Wu
- College of Bioscience and Engineering, South China University of Technology, Guangzhou 510640, China.
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Juhasz AL, Naidu R. Explosives: fate, dynamics, and ecological impact in terrestrial and marine environments. REVIEWS OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2007; 191:163-215. [PMID: 17708075 DOI: 10.1007/978-0-387-69163-3_6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
An explosive or energetic compound is a chemical material that, under the influence of thermal or chemical shock, decomposes rapidly with the evolution of large amounts of heat and gas. Numerous compounds and compositions may be classified as energetic compounds; however, secondary explosives, such as TNT, RDX, and HMX pose the largest potential concern to the environment because they are produced and used in defense in the greatest quantities. The environmental fate and potential hazard of energetic compounds in the environment is affected by a number of physical, chemical, and biological processes. Energetic compounds may undergo transformation through biotic or abiotic degradation. Numerous organisms have been isolated with the ability to degrade/transform energetic compounds as a sole carbon source, sole nitrogen source, or through cometabolic processes under aerobic or anaerobic conditions. Abiotic processes that lead to the transformation of energetic compounds include photolysis, hydrolysis, and reduction. The products of these reactions may be further transformed by microorganisms or may bind to soil/sediment surfaces through covalent binding or polymerization and oligomerization reactions. Although considerable research has been performed on the fate and dynamics of energetic compounds in the environment, data are still gathering on the impact of TNT, RDX, and HMX on ecological receptors. There is an urgent need to address this issue and to direct future research on expanding our knowledge on the ecological impact of energetic transformation products. In addition, it is important that energetic research considers the concept of bioavailability, including factors influencing soil/sediment aging, desorption of energetic compounds from varying soil and sediment types, methods for modeling/predicting energetic bioavailability, development of biomarkers of energetic exposure or effect, and the impact of bioavailability on ecological risk assessment.
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Affiliation(s)
- Albert L Juhasz
- Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, Adelaide, Australia, 5095
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Robertson BK, Jjemba PK. Enhanced bioavailability of sorbed 2,4,6-trinitrotoluene (TNT) by a bacterial consortium. CHEMOSPHERE 2005; 58:263-270. [PMID: 15581929 DOI: 10.1016/j.chemosphere.2004.08.080] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2003] [Revised: 08/04/2004] [Accepted: 08/27/2004] [Indexed: 05/24/2023]
Abstract
Large quantities of trinitrotoluene (TNT) have been associated with past and present military activities worldwide. Because this contaminant is highly toxic and strongly sorbs to soil particles, bacteria that are able to transform it have had very little success, if any. This study was conducted to evaluate the bioavailability of 14C-labeled TNT in soil for microbial mineralization. Sorption-desorption experiments indicated that a Kendaia loam soil effectively adsorbs this explosive compound, with approximately 30-45% of the added TNT remaining sorbed to the soil after a total of 10 washings. A bacterial consortium isolated from explosive-contaminated sites was prepared in liquid medium and then tested in a TNT-spiked Kendaia loam soil. The concentration of TNT in the soil that was inoculated with the bacterial consortium was reduced by more than 30% of the initial concentration compared to the soil that did not contain the bacterial consortium within a period of 20 weeks. Nearly half of the TNT was mineralized as determined by the percentage of 14CO2 produced. Only one member of the consortium (i.e., Enterobacter sp.) significantly mineralized 25% of TNT although the extent of mineralization was significantly enhanced to 35% in the presence of the other two members of the consortium. The data suggest that some of the strongly adsorbed TNT may be accessible for metabolism if conditions for the right combination of microorganisms with specialized capabilities are optimized. The remaining sorbed fraction of substrate is presumably sequestered and thus unavailable to the microorganisms.
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Affiliation(s)
- B K Robertson
- Department of Biological Sciences, Alabama State University, 915 South Jackson Street, Montgomery, AL 36101, USA.
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Popesku JT, Singh A, Zhao JS, Hawari J, Ward OP. Metabolite production during transformation of 2,4,6-trinitrotoluene (TNT) by a mixed culture acclimated and maintained on crude oil-containing media. Appl Microbiol Biotechnol 2004; 65:739-46. [PMID: 15133643 DOI: 10.1007/s00253-004-1625-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2004] [Revised: 03/29/2004] [Accepted: 04/07/2004] [Indexed: 11/24/2022]
Abstract
Metabolites formed during 2,4,6-trinitrotoluene (TNT) removal by a mixed bacterial culture (acclimated and maintained on crude oil-containing medium and capable of high rates of TNT removal) were characterized. In resting cell experiments in the absence of glucose, 46.2 mg/l TNT were removed in 171 h (87.5% removal), with a combined total formation of 7.7 mg/l amino-4,6-dinitrotoluene (ADNT) and 0.3 mg/l 4,4'-azoxytetranitrotoluene and 2',4-azoxytetranitrotoluene, leaving 70% of the initial TNT unaccounted for. In the presence of glucose, resting cells removed 45.4 mg/l TNT in 49 h (95.5% removal), with 9.1 mg/l ADNT and 2.4 mg/l azoxy compounds being produced, leaving 70.3% of the TNT unaccounted for. Growing cells (glucose present) were capable of removing 44.2 mg/l TNT within 21 h (97.9% removal), with the concomitant formation of 1.8 mg/l ADNTs and 2.2 mg/l azoxy compounds. Denitrated TNT in the form of 2,6-dinitrotoluene was also produced in growing cells with a maximum amount of 1.31 mg/l after 28 h, followed by a slight decrease with time, leaving 88.5% of the initial TNT unaccounted for after 171 h. Radiolabeled (14)C-TNT studies revealed 4.14% mineralization after an incubation period of 163 days with growing cells.
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Affiliation(s)
- Jason T Popesku
- Department of Biology, University of Waterloo, Waterloo, N2L 3G1, Ontario, Canada
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Rosser SJ, Basran A, Travis ER, French CE, Bruce NC. Microbial transformations of explosives. ADVANCES IN APPLIED MICROBIOLOGY 2002; 49:1-35. [PMID: 11757347 DOI: 10.1016/s0065-2164(01)49008-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- S J Rosser
- Institute of Biotechnology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QT, United Kingdom
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13
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Affiliation(s)
- C E French
- Institute of Cell and Molecular Biology, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JR, UK.
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Johnson GR, Smets BF, Spain JC. Oxidative transformation of aminodinitrotoluene isomers by multicomponent dioxygenases. Appl Environ Microbiol 2001; 67:5460-6. [PMID: 11722893 PMCID: PMC93330 DOI: 10.1128/aem.67.12.5460-5466.2001] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2001] [Accepted: 09/11/2001] [Indexed: 11/20/2022] Open
Abstract
The electron-withdrawing nitro substituents of 2,4,6-trinitrotoluene (TNT) make the aromatic ring highly resistant to oxidative transformation. The typical biological transformation of TNT involves reduction of one or more of the nitro groups of the ring to produce the corresponding amine. Reduction of a single nitro substituent of TNT to an amino substituent increases the electron density of the aromatic nucleus considerably. The comparatively electron-dense nuclei of the aminodinitrotoluene (ADNT) isomers would be expected to be more susceptible to oxygenase attack than TNT. The hypothesis was tested by evaluating three nitroarene dioxygenases for the ability to hydroxylate the ADNT isomers. The predominant reaction was dioxygenation of the ring to yield nitrite and the corresponding aminomethylnitrocatechol. A secondary reaction was benzylic monooxygenation to form aminodinitrobenzyl alcohol. The substrate preferences and catalytic specificities of the three enzymes differed considerably. The discovery that the ADNT isomers are substrates for the nitroarene dioxygenases reveals the potential for extensive bacterial transformation of TNT under aerobic conditions.
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Affiliation(s)
- G R Johnson
- Air Force Research Laboratory, Tyndall Air Force Base, Florida 32403, USA
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Esteve-Núñez A, Caballero A, Ramos JL. Biological degradation of 2,4,6-trinitrotoluene. Microbiol Mol Biol Rev 2001; 65:335-52, table of contents. [PMID: 11527999 PMCID: PMC99030 DOI: 10.1128/mmbr.65.3.335-352.2001] [Citation(s) in RCA: 255] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Nitroaromatic compounds are xenobiotics that have found multiple applications in the synthesis of foams, pharmaceuticals, pesticides, and explosives. These compounds are toxic and recalcitrant and are degraded relatively slowly in the environment by microorganisms. 2,4,6-Trinitrotoluene (TNT) is the most widely used nitroaromatic compound. Certain strains of Pseudomonas and fungi can use TNT as a nitrogen source through the removal of nitrogen as nitrite from TNT under aerobic conditions and the further reduction of the released nitrite to ammonium, which is incorporated into carbon skeletons. Phanerochaete chrysosporium and other fungi mineralize TNT under ligninolytic conditions by converting it into reduced TNT intermediates, which are excreted to the external milieu, where they are substrates for ligninolytic enzymes. Most if not all aerobic microorganisms reduce TNT to the corresponding amino derivatives via the formation of nitroso and hydroxylamine intermediates. Condensation of the latter compounds yields highly recalcitrant azoxytetranitrotoluenes. Anaerobic microorganisms can also degrade TNT through different pathways. One pathway, found in Desulfovibrio and Clostridium, involves reduction of TNT to triaminotoluene; subsequent steps are still not known. Some Clostridium species may reduce TNT to hydroxylaminodinitrotoluenes, which are then further metabolized. Another pathway has been described in Pseudomonas sp. strain JLR11 and involves nitrite release and further reduction to ammonium, with almost 85% of the N-TNT incorporated as organic N in the cells. It was recently reported that in this strain TNT can serve as a final electron acceptor in respiratory chains and that the reduction of TNT is coupled to ATP synthesis. In this review we also discuss a number of biotechnological applications of bacteria and fungi, including slurry reactors, composting, and land farming, to remove TNT from polluted soils. These treatments have been designed to achieve mineralization or reduction of TNT and immobilization of its amino derivatives on humic material. These approaches are highly efficient in removing TNT, and increasing amounts of research into the potential usefulness of phytoremediation, rhizophytoremediation, and transgenic plants with bacterial genes for TNT removal are being done.
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Affiliation(s)
- A Esteve-Núñez
- Department of Biochemistry and Molecular and Cellular Biology of Plants, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Cientificas, Apdo Correos 419, E-18008 Granada, Spain
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Peres CM, Agathos SN. Biodegradation of nitroaromatic pollutants: from pathways to remediation. BIOTECHNOLOGY ANNUAL REVIEW 2001; 6:197-220. [PMID: 11193295 DOI: 10.1016/s1387-2656(00)06023-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Nitroaromatic compounds are important contaminants of the environment, mainly of anthropogenic origin. They are produced as intermediates and products in the industrial manufacturing of dyes, explosives, pesticides, etc. Their toxicity has been extensively demonstrated in a whole range of living organisms, and nitroaromatic contamination dating from World War II is the proof of the recalcitrance of such compounds to microbial recycling. In spite of this, bacteria have evolved diverse pathways that allow them to mineralize specific nitroaromatic compounds. Degradation sequences initiated by an oxidation, an attack by a hydride ion, or a partial reduction have been documented. Some of these reactions have been exploited in bioreactors. Although pathways and enzymes involved are rather well understood, the molecular basis of these pathways is still currently under investigation. However, productive metabolism is an exception. As a rule, most bacteria are only able to reduce the nitro group into an amino function. This reduction is cometabolic: the metabolism of exogenous carbon sources is required to provide reducing equivalents. Composting and processes in bioreactors have exploited the easy reduction of the nitroaromatic compounds. In the case an amino-aromatic compound is produced, it is important to incorporate it in the remediation scheme. Some processes dealing with both nitro- and amino-aromatic compounds have been described, the amino derivative being either mineralized by the same or, more often, another microorganism, or immobilized on soil particles. Depending on the nitroaromatic compound and the environment it is contaminating, a whole range of reactions and reactor studies are now available to help devise a successful remediation strategy.
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Affiliation(s)
- C M Peres
- Unité de Génie Biologique, Université Catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium
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Pak JW, Knoke KL, Noguera DR, Fox BG, Chambliss GH. Transformation of 2,4,6-trinitrotoluene by purified xenobiotic reductase B from Pseudomonas fluorescens I-C. Appl Environ Microbiol 2000; 66:4742-50. [PMID: 11055918 PMCID: PMC92374 DOI: 10.1128/aem.66.11.4742-4750.2000] [Citation(s) in RCA: 119] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The enzymatic transformation of 2,4,6-trinitrotoluene (TNT) by purified XenB, an NADPH-dependent flavoprotein oxidoreductase from Pseudomonas fluorescens I-C, was evaluated by using natural abundance and [U-(14)C]TNT preparations. XenB catalyzed the reduction of TNT either by hydride addition to the aromatic ring or by nitro group reduction, with the accumulation of various tautomers of the protonated dihydride-Meisenheimer complex of TNT, 2-hydroxylamino-4,6-dinitrotoluene, and 4-hydroxylamino-2, 6-dinitrotoluene. Subsequent reactions of these metabolites were nonenzymatic and resulted in predominant formation of at least three dimers with an anionic m/z of 376 as determined by negative-mode electrospray ionization mass spectrometry and the release of approximately 0.5 mol of nitrite per mol of TNT consumed. The extents of the initial enzymatic reactions were similar in the presence and in the absence of O(2), but the dimerization reaction and the release of nitrite were favored under aerobic conditions or under anaerobic conditions in the presence of NADP(+). Reactions of chemically and enzymatically synthesized and high-pressure liquid chromatography-purified TNT metabolites showed that both a hydroxylamino-dinitrotoluene isomer and a tautomer of the protonated dihydride-Meisenheimer complex of TNT were required precursors for the dimerization and nitrite release reactions. The m/z 376 dimers also reacted with either dansyl chloride or N-1-naphthylethylenediamine HCl, providing evidence for an aryl amine functional group. In combination, the experimental results are consistent with assigning the chemical structures of the m/z 376 species to various isomers of amino-dimethyl-tetranitrobiphenyl. A mechanism for the formation of these proposed TNT metabolites is presented, and the potential enzymatic and environmental significance of their formation is discussed.
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Affiliation(s)
- J W Pak
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin 53706, USA
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Park HS, Lim SJ, Chang YK, Livingston AG, Kim HS. Degradation of chloronitrobenzenes by a coculture of Pseudomonas putida and a Rhodococcus sp. Appl Environ Microbiol 1999; 65:1083-91. [PMID: 10049867 PMCID: PMC91148 DOI: 10.1128/aem.65.3.1083-1091.1999] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A single microorganism able to mineralize chloronitrobenzenes (CNBs) has not been reported, and degradation of CNBs by coculture of two microbial strains was attempted. Pseudomonas putida HS12 was first isolated by analogue enrichment culture using nitrobenzene (NB) as the substrate, and this strain was observed to possess a partial reductive pathway for the degradation of NB. From high-performance liquid chromatography-mass spectrometry and 1H nuclear magnetic resonance analyses, NB-grown cells of P. putida HS12 were found to convert 3- and 4-CNBs to the corresponding 5- and 4-chloro-2-hydroxyacetanilides, respectively, by partial reduction and subsequent acetylation. For the degradation of CNBs, Rhodococcus sp. strain HS51, which degrades 4- and 5-chloro-2-hydroxyacetanilides, was isolated and combined with P. putida HS12 to give a coculture. This coculture was confirmed to mineralize 3- and 4-CNBs in the presence of an additional carbon source. A degradation pathway for 3- and 4-CNBs by the two isolated strains was also proposed.
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Affiliation(s)
- H S Park
- Department of Chemical Engineering, Korea Advanced Institute of Science and Technology, 373-1 Kusong-dong, Yusong-gu, Taejon 305-701, Korea
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Bruns-Nagel D, Schmidt TC, Drzyzga O, von Löw E, Steinbach K. Identification of oxidized TNT metabolites in soil samples of a former ammunition plant. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 1999; 6:7-10. [PMID: 19005856 DOI: 10.1007/bf02987113] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/1998] [Accepted: 07/09/1998] [Indexed: 05/27/2023]
Abstract
Water extracts of soil samples of the former ammunition plant "Tanne" near Clausthal-Zellerfeld, Lower Saxony, Germany, were investigated for highly polar oxidized 2,4,6-trinitrotoluene (TNT) metabolites. 0.4 to 9.0 mg/kg dry soil 2,4,6-trinitrobenzoic acid (TNBA) and 5.8 to 544 mg/kg dry soil 2-amino-4,6-dinitrobenzoic acid (2-ADNBA) were found. In addition to the oxidized metabolites, TNT, 4- and 2-aminodinitrotoluene (4- and 2-ADNT), and 2,4-dinitrotoluene (2,4-DNT) were extractable with water. Most interestingly, in one sample, 2-ADNBA represented the main contaminant. The origin of the oxidized nitroaromatics is unknown at this time. They might be generated chemically or photochemically. Furthermore, a biological synthesis seems possible.
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Affiliation(s)
- D Bruns-Nagel
- Institute of Immunology and Environmental Hygiene, Philipps University Marburg, Pilgrimstein 2, D-35037, Marburg, Germany.
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Breitung J, Bruns-Nagel D, Steinbach K, Blotevogel KH, Gorontzy T, Dillert R, Winterberg R, Stoffers H, Haas R, Müller M, Asbach P, Kaminski L, von Löw E, Gemsa D. TNT in Komposten und Flüssigkultur. ACTA ACUST UNITED AC 1996. [DOI: 10.1007/bf03038775] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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