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Gupta S, Goel SS, Ramanathan G, Ronen Z. Biotransformation of 2,4,6-trinitrotoluene by Diaphorobacter sp. strain DS2. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:120749-120762. [PMID: 37943434 DOI: 10.1007/s11356-023-30651-0] [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: 06/15/2023] [Accepted: 10/20/2023] [Indexed: 11/10/2023]
Abstract
Diaphorobacter strain DS2 degrades 3-nitrotoluene and 2-nitrotoluene via ring oxidation with 3-nitrotoluene dioxygenase (3NTDO). In the current study, we hypothesized that 3NTDO might also be involved in the degradation of 2,4,6-trinitrotoluene (TNT), a major nitroaromatic explosive contaminant in soil and groundwater. Strain DS2 transforms TNT as a sole carbon and nitrogen source when grown on it. Ammonium chloride and succinate in the medium accelerated the TNT degradation rate. A resting cell experiment suggested that TNT does not compete with 3NT degradation (no negative impact of TNT on the reaction velocity for 3NT). Enzyme assay with 3NTDO did not exhibit TNT transformation activity. The above results confirmed that 3NTDO of DS2 is not responsible for TNT degradation. In the resting cell experiment, within 10 h, 4ADNT completely degraded. The degradation of 2ADNT was 97% at the same time. We hypothesized that 3NTDO involve in this reaction. Based on the DS2 genome, we proposed that the N-ethylmaleimide reductases (nemA) were involved in the initial reduction of the nitro group and aromatic ring of TNT. Our findings suggest that strain DS2 could be helpful for the removal of TNT from contaminated sites with or without any additional carbon and nitrogen source and with minimal accumulation of undesirable intermediates.
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Affiliation(s)
- Swati Gupta
- Department of Environmental Hydrology and Microbiology, The Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sde Boker Campus 8490000, Be'er Sheva, Israel
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India
| | - Shikhar S Goel
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India
| | - Gurunath Ramanathan
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India
| | - Zeev Ronen
- Department of Environmental Hydrology and Microbiology, The Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sde Boker Campus 8490000, Be'er Sheva, Israel.
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2
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Yin ML, Zhao SP, Lai JL, Yang X, Dong B, Zhu YB, Zhang Y. Oxygen-insensitive nitroreductase bacteria-mediated degradation of TNT and proteomic analysis. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:116227-116238. [PMID: 37907824 DOI: 10.1007/s11356-023-30568-8] [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: 06/20/2023] [Accepted: 10/16/2023] [Indexed: 11/02/2023]
Abstract
2,4,6-trinitrotoluene (TNT) is a nitroaromatic compound that causes soil and groundwater pollution during manufacture, transportation, and use, posing significant environmental and safety hazards. In this study, a TNT-degrading strain, Bacillus cereus strain T4, was screened and isolated from TNT-contaminated soil to explore its degradation characteristics and proteomic response to TNT. The results showed that after inoculation with the bacteria for 4 h, the TNT degradation rate reached 100% and was transformed into 2-amino-4,6-dinitrotoluene (2-ADNT), 4-amino-2,6-dinitrotoluene (4-ADNT), 2,4-diamino-6-nitrotoluene (2,4-DANT), and 2,6-diamino-4-nitrotoluene (2,6-DANT), accompanied by the accumulation of nitrite and ammonium ions. Through proteomic sequencing, we identified 999 differentially expressed proteins (482 upregulated, 517 downregulated), mainly enriched in the pentose phosphate, glycolysis/gluconeogenesis, and amino acid metabolism pathways. In addition, the significant upregulation of nitroreductase and N-ethylmaleimide reductase was closely related to TNT denitration and confirmed that the strain T4 converted TNT into intermediate metabolites such as 2-ADNT and 4-ADNT. Therefore, Bacillus cereus strain T4 has the potential to degrade TNT and has a high tolerance to intermediate products, which may effectively degrade nitroaromatic pollutants such as TNT in situ remediation in combination with other bacterial communities.
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Affiliation(s)
- Mao-Ling Yin
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, 621010, China
| | - San-Ping Zhao
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China.
| | - Jin-Long Lai
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Xu Yang
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Bin Dong
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Yong-Bing Zhu
- State Key Laboratory of NBC Protection for Civilian, Beijing, 102205, China
| | - Yu Zhang
- School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang, 621010, China
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3
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Kundu K, Van Landuyt J, Mattelin V, Martin B, Neyts M, Parmentier K, Boon N. Enhanced removal of warfare agent tri-nitro-toluene by a Methylophaga-dominated microbiome. MARINE POLLUTION BULLETIN 2023; 190:114866. [PMID: 37001405 DOI: 10.1016/j.marpolbul.2023.114866] [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: 01/07/2023] [Revised: 03/08/2023] [Accepted: 03/20/2023] [Indexed: 06/19/2023]
Abstract
Historical exposure of the marine environment to 2,4,6-trinitrotoluene (TNT) happened due to the dumping of left-over munitions. Despite significant research on TNT decontamination, the potential of marine microbiome for TNT degradation remains only little explored. In this study, TNT degradation experiments were conducted with sediment located near the World War I munition dumpsite - Paardenmarkt in the Belgian part of North Sea. A slow removal was observed using TNT as sole source of C and N, which could be enhanced by adding methanol. Degradation was reflected in nitro-reduced metabolites and microbial growth. 16S Illumina sequencing analysis revealed several enriched genera that used TNT as a sole source of C and N - Colwellia, Thalossospira, and Methylophaga. Addition of methanol resulted in increased abundance of Methylophaga, which corresponded to the rapid removal of TNT. Methanol enhanced the degradation by providing additional energy and establishing syntrophic association between methanol-utilizing and TNT-utilizing bacteria.
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Affiliation(s)
- Kankana Kundu
- Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, University of Ghent, Coupure Links 653, 9000 Ghent, Belgium.
| | - Josefien Van Landuyt
- Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, University of Ghent, Coupure Links 653, 9000 Ghent, Belgium
| | - Valérie Mattelin
- Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, University of Ghent, Coupure Links 653, 9000 Ghent, Belgium
| | - Bram Martin
- Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, University of Ghent, Coupure Links 653, 9000 Ghent, Belgium
| | - Marijke Neyts
- Royal Belgian Institute of Natural Science (RBIN), 3de en 23ste Linieregimentsplein, 8400 Oostende, Belgium
| | - Koen Parmentier
- Royal Belgian Institute of Natural Science (RBIN), 3de en 23ste Linieregimentsplein, 8400 Oostende, Belgium
| | - Nico Boon
- Center for Microbial Ecology and Technology (CMET), Faculty of Bioscience Engineering, University of Ghent, Coupure Links 653, 9000 Ghent, Belgium; Centre for Advanced Process Technology for Urban Resource recovery (CAPTURE), Ghent, Belgium.
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4
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Critical Role of Monooxygenase in Biodegradation of 2,4,6-Trinitrotoluene by Buttiauxella sp. S19-1. Molecules 2023; 28:molecules28041969. [PMID: 36838956 PMCID: PMC9958683 DOI: 10.3390/molecules28041969] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 02/10/2023] [Accepted: 02/17/2023] [Indexed: 02/22/2023] Open
Abstract
2,4,6-Trinitrotoluene (TNT) is an aromatic pollutant that is difficult to be degraded in the natural environment. The screening of efficient degrading bacteria for bioremediation of TNT has received much attention from scholars. In this paper, transcriptome analysis of the efficient degrading bacterium Buttiauxella sp. S19-1 revealed that the monooxygenase gene (BuMO) was significantly up-regulated during TNT degradation. S-ΔMO (absence of BuMO gene in S19-1 mutant) degraded TNT 1.66-fold less efficiently than strain S19-1 (from 71.2% to 42.9%), and E-MO mutant (Escherichia coli BuMO-expressing strain) increased the efficiency of TNT degradation 1.33-fold (from 52.1% to 69.5%) for 9 h at 180 rpm at 27 °C in LB medium with 1.4 µg·mL-1 TNT. We predicted the structure of BuMO and purified recombinant BuMO (rBuMO). Its specific activity was 1.81 µmol·min-1·mg-1 protein at pH 7.5 and 35 °C. The results of gas chromatography mass spectrometry (GC-MS) analysis indicated that 4-amino-2,6-dinitrotoluene (ADNT) is a metabolite of TNT biodegradation. We speculate that MO is involved in catalysis in the bacterial degradation pathway of TNT in TNT-polluted environment.
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Gupta S, Goel SS, Siebner H, Ronen Z, Ramanathan G. Transformation of 2, 4, 6-trinitrotoluene by Stenotrophomonas strain SG1 under aerobic and anaerobic conditions. CHEMOSPHERE 2023; 311:137085. [PMID: 36328316 DOI: 10.1016/j.chemosphere.2022.137085] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 10/28/2022] [Accepted: 10/29/2022] [Indexed: 06/16/2023]
Abstract
TNT, or 2,4,6-trinitrotoluene, is a common explosive that can contaminate soil and groundwater in production sites, military training areas, and disposal locations. The compound is highly toxic; therefore, there is an urgent need to rehabilitate the impacted environments. Harnessing the microbial ability to biodegrade TNT into environmentally harmless compound(s) is one approach to remediating contaminated sites. In our study, we report on the genomic and metabolic ability of Stenotrophomonas strain SG1 to degrade TNT under aerobic and anaerobic conditions. The bacterial strain SG1 was first isolated as a contaminant from a culture of Diaphorobacter sp. strain DS2 over minimal media supplemented with TNT. The draft genome assembly of strain SG1 is ∼4.7 Mb and is distributed among 358 contigs. The homology search against the custom database of enzymes responsible for TNT biodegradation revealed the presence of three N-ethylmaleimide reductases (NemA) with a defined KEGG ortholog and KEGG pathway of TNT degradation. The presence of respiratory nitrate reductases has also been mapped, which supports denitrification under anaerobic conditions. Experimentally, the TNT transformation rate accelerated when carbon sources, such as sodium acetate, sodium citrate, sodium succinate, sucrose, and glucose (final concentration of 5 mM), were added. Citrate promoted the highest growth and TNT transformation ratio (88.35%) in 120 h. With the addition of 5 mM ammonium chloride, TNT completely disappeared in the citrate and sucrose-containing treatments in 120 h. However, higher biomass was obtained in the sucrose and glucose-containing treatments in 120 h. During incubation, the formation of amino dinitrotoluene isomers, dinitrotoluene isomers, trinitrobenzene, azoxy isomers, diaryl hydroxylamines, and corresponding secondary amines was confirmed by GC/MS and UPLC/MS. 2-Amino-4-nitrotoluene, 4-amino-2-nitrotoluene, and 2-amino-6-nitrotoluene were also identified in the culture supernatant by GC/MS. Under anaerobic conditions, TNT completely disappeared in the citrate and citrate plus nitrate treatments. Since the strain shows the ability to remove TNT, this research should be useful in basic research and practical applications for removing TNT from wastewater.
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Affiliation(s)
- Swati Gupta
- Department of Environmental Hydrology and Microbiology, The Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sde Boker Campus, 8490000, Israel; Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India
| | - Shikhar S Goel
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India
| | - Hagar Siebner
- Department of Environmental Hydrology and Microbiology, The Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sde Boker Campus, 8490000, Israel
| | - Zeev Ronen
- Department of Environmental Hydrology and Microbiology, The Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sde Boker Campus, 8490000, Israel.
| | - Gurunath Ramanathan
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India.
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Gupta S, Siebner H, Ramanathan G, Ronen Z. Inhibition effect of 2,4,6-trinitrotoluene (TNT) on RDX degradation by rhodococcus strains isolated from contaminated soil and water. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 311:120018. [PMID: 36002099 DOI: 10.1016/j.envpol.2022.120018] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 07/31/2022] [Accepted: 08/17/2022] [Indexed: 06/15/2023]
Abstract
2,4,6-trinitrotoluene (TNT) is a highly toxic explosive that contaminates soil and water and may interfere with the degradation of co-occurring compounds, such as hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX). We proposed that TNT may influence RDX-degrading bacteria via either general toxicity or a specific effect on the |RDX degradation mechanisms. Thus, we examined the impact of TNT on RDX degradation by Rhodococcus strains YH1, T7, and YY1, which were isolated from an explosives-polluted environment. Although partly degraded, TNT did not support the growth of any of the strains when used as either sole carbon or sole nitrogen sources, or as carbon and nitrogen sources. The incubation of a mixture of TNT (25 mg/l) and RDX (20 mg/l) completely inhibited RDX degradation. The effect of TNT on the cytochrome P450, catalyzing RDX degradation, was tested in a resting cell experiment, proving that TNT inhibits XplA protein activity. A dose-response experiment showed that the IC50/trans values for YH1, T7, and YY1 were 7.272, 5.098, and 9.140 (mg/l of TNT), respectively, illustrating variable sensitivity to TNT among the strains. The expression of xplA was also strongly suppressed by TNT. Cells that were pre-grown with RDX (allowing xplA expression) and incubated with ammonium chloride, glucose, and TNT, completely transformed into their amino dinitrotoluene isomers and formed azoxy toluene isomers. The presence of oxygen-insensitive nitroreductase that enable reduction of the nitro group in the presence of O2 in the genomes of these strains suggests that they are responsible for TNT transformation in the cultures. The experimental results concluded that TNT has an adverse effect on RDX degradation by the examined strains. It inhibits RDX degradation due to the direct impact on cytochrome P450, xplA, or its expression. The tested strains can transform TNT independently of RDX. Thus, degradation of both compounds is possible if TNT concentrations are below their IC50 values.
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Affiliation(s)
- Swati Gupta
- Department of Environmental Hydrology and Microbiology, The Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sde Boker Campus, 8490000, Israel; Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Hagar Siebner
- Department of Environmental Hydrology and Microbiology, The Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sde Boker Campus, 8490000, Israel
| | - Gurunath Ramanathan
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Zeev Ronen
- Department of Environmental Hydrology and Microbiology, The Zuckerberg Institute for Water Research, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sde Boker Campus, 8490000, Israel.
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7
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Yakovleva G, Kurdy W, Gorbunova A, Khilyas I, Lochnit G, Ilinskaya O. Bacillus pumilus proteome changes in response to 2,4,6-trinitrotoluene-induced stress. Biodegradation 2022; 33:593-607. [PMID: 35980495 DOI: 10.1007/s10532-022-09997-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 08/08/2022] [Indexed: 11/24/2022]
Abstract
2,4,6-Trinitrotoluene (TNT) is the most widely used nitroaromatic compound and is highly resistant to degradation. Most aerobic microorganisms reduce TNT to amino derivatives via formation of nitroso- and hydroxylamine intermediates. Although pathways of TNT degradation are well studied, proteomic analysis of TNT-degrading bacteria was done only for some individual Gram-negative strains. Here, we isolated a Gram-positive strain from TNT-contaminated soil, identified it as Bacillus pumilus using 16S rRNA sequencing, analyzed its growth, the level of TNT transformation, ROS production, and revealed for the first time the bacillary proteome changes at toxic concentration of TNT. The transformation of TNT at all studied concentrations (20-200 mg/L) followed the path of nitro groups reduction with the formation of 4-amino-2,6-dinitrotoluene. Hydrogen peroxide production was detected during TNT transformation. Comparative proteomic analysis of B. pumilus showed that TNT (200 mg/L) inhibited expression of 46 and induced expression of 24 proteins. Among TNT upregulated proteins are those which are responsible for the reductive pathway of xenobiotic transformation, removal of oxidative stress, DNA repair, degradation of RNA and cellular proteins. The production of ribosomal proteins, some important metabolic proteins and proteins involved in cell division are downregulated by this xenobiotic.
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Affiliation(s)
- Galina Yakovleva
- Microbiology Department, Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, Kremlevskaya St., 18, Tatarstan, Kazan, Russia, 420008
| | - William Kurdy
- Microbiology Department, Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, Kremlevskaya St., 18, Tatarstan, Kazan, Russia, 420008
| | - Anna Gorbunova
- Microbiology Department, Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, Kremlevskaya St., 18, Tatarstan, Kazan, Russia, 420008
| | - Irina Khilyas
- Microbiology Department, Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, Kremlevskaya St., 18, Tatarstan, Kazan, Russia, 420008
| | - Guenter Lochnit
- Protein Analytics, Institute of Biochemistry, Faculty of Medicine, Justus Liebig University Giessen, Friedrichstrasse 24, Giessen, Germany, 35392
| | - Olga Ilinskaya
- Microbiology Department, Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, Kremlevskaya St., 18, Tatarstan, Kazan, Russia, 420008.
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Sriprom W, Choodum A, Phawachalotorn C, Wongniramaikul W, Limsakul W. Tetramethylammonium Hydroxide-doped Starch Film as a Colorimetric Sensor for Trinitrotoluene Detection. ANAL SCI 2020; 36:1261-1267. [PMID: 32475897 DOI: 10.2116/analsci.20p117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A tetramethylammonium hydroxide (TMAH)-doped starch film was developed for trinitrotoluene (TNT) detection. A purple Janowsky anion was obtained from the reaction of TNT with released TMAH. When the film was used in conjunction with digital image colorimetry (DIC), rapid quantitative analysis of TNT was achieved. The Red-Green-Blue (RGB) intensities analyzed from digital photographs of the purple product were used to establish calibration curves for TNT. A wide linear range (2.5 to 50 mgL-1) with good linearity (R2 > 0.99) was achieved for the quantification of TNT. Good precision (1.73 to 3.74%RSD) was obtained for inter-day tests (n = 5). The films were applied to test four post-blast soil samples and two positive results were observed. The concentrations quantified by DIC were in good agreement with spectrophotometry. The film was able to be stored in a freezer for 3 months with <4.3% change in performance.
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Affiliation(s)
- Wilasinee Sriprom
- Integrated Science and Technology Research Center, Faculty of Technology and Environment, Prince of Songkla University
| | - Aree Choodum
- Integrated Science and Technology Research Center, Faculty of Technology and Environment, Prince of Songkla University
| | - Chanadda Phawachalotorn
- Department of Applied Science and Business Management, King Mongkut's Institute of Technology Ladkrabang, Prince of Chumphon Campus
| | - Worawit Wongniramaikul
- Integrated Science and Technology Research Center, Faculty of Technology and Environment, Prince of Songkla University.,Research Program: The Development of Management System for Reduction and Control of Water Contamination and Distribution in Songkhla Lake Basin and the Western Coastline of the South of Thailand, Center of Excellence on Hazardous Substance Management (HSM)
| | - Wadcharawadee Limsakul
- Integrated Science and Technology Research Center, Faculty of Technology and Environment, Prince of Songkla University
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Montgomery MT, Boyd TJ, Hall NS, Paerl HW, Osburn CL. Ecosystem Capacity for Microbial Biodegradation of Munitions Compounds and Phenanthrene in Three Coastal Waterways in North Carolina, United States. ACS OMEGA 2020; 5:7326-7341. [PMID: 32280874 PMCID: PMC7144167 DOI: 10.1021/acsomega.9b04188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Accepted: 02/18/2020] [Indexed: 06/11/2023]
Abstract
Munitions compounds (i.e., 2,4,6-trinitrotoluene (TNT), octahy-dro-1,3,5,7-tetranitro-1,3,5,7-tetrazocin (HMX), and hexadydro-1,3,5-trinitro-1,3,5-triazin (RDX), also called energetics) were originally believed to be recalcitrant to microbial biodegradation based on historical groundwater chemical attenuation data and laboratory culture work. More recently, it has been established that natural bacterial assemblages in coastal waters and sediment can rapidly metabolize these organic nitrogen sources and even incorporate their carbon and nitrogen into bacterial biomass. Here, we report on the capacity of natural microbial assemblages in three coastal North Carolina (United States) estuaries to metabolize energetics and phenanthrene (PHE), a proxy for terrestrial aromatic compounds. Microbial assemblages generally had the highest ecosystem capacity (mass of the compound mineralized per average estuarine residence time) for HMX (21-5463 kg) > RDX (1.4-5821 kg) ≫ PHE (0.29-660 kg) > TNT (0.25-451 kg). Increasing antecedent precipitation tended to decrease the ecosystem capacity to mineralize TNT in the Newport River Estuary, and PHE and TNT mineralization were often highest with increasing salinity. There was some evidence from the New River Estuary that increased N-demand (due to a phytoplankton bloom) is associated with increased energetic mineralization rates. Using this type of analysis to determine the ecosystem capacity to metabolize energetics can explain why these compounds are rarely detected in seawater and marine sediment, despite the known presence of unexploded ordnance or recent use in military training exercises. Overall, measuring the ecosystem capacity may help predict the effects of climate change (warming and altered precipitation patterns) and other perturbations on exotic compound fate and transport within ecosystems and provide critical information for managers and decision-makers to develop management strategies based on these changes.
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Affiliation(s)
- Michael T. Montgomery
- Chemistry
Division, Naval Research Laboratory, 4555 Overlook Avenue Southwest, Washington, District of Columbia 20375, United States
| | - Thomas J. Boyd
- Chemistry
Division, Naval Research Laboratory, 4555 Overlook Avenue Southwest, Washington, District of Columbia 20375, United States
| | - Nathan S. Hall
- Institute
of Marine Sciences, University of North
Carolina, Morehead City, North Carolina 28557, United States
| | - Hans W. Paerl
- Institute
of Marine Sciences, University of North
Carolina, Morehead City, North Carolina 28557, United States
| | - Christopher L. Osburn
- Department
of Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, North Carolina 27695, United States
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Yang Z, Wei T, Huang H, Yang H, Zhou Y, Xu D. Insights into the biotransformation of 2,4,6-trinitrotoluene by the old yellow enzyme family of flavoproteins. A computational study. Phys Chem Chem Phys 2019; 21:11589-11598. [PMID: 30801593 DOI: 10.1039/c8cp07873d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Biodegradation is a cost-effective and environmentally friendly alternative to removing 2,4,6-trinitrotoluene (TNT) pollution. However, mechanisms of TNT biodegradation have been elusive. To enhance the understanding of TNT biotransformation by the Old Yellow Enzyme (OYE) family, we investigated the crucial first-step hydrogen-transfer reaction by molecular dynamics simulations, docking technologies and empirical valence bond calculations. We revealed the significance of the π-π stacking conformation between the substrate TNT and the reduced flavin mononucleotide (FMNH2) cofactor, which is a prerequisite for the aromatic ring reduction of TNT. Under the π-π stacking conformation, the barrier of the hydrogen-transfer reaction in the aromatic ring reduction is about 16 kcal mol-1 lower than that of nitro group reduction. Then, we confirmed the mechanism of controlling the π-π stacking, that is, the π-π interaction competition mechanism. It indicates that the π-π stacking of TNT and FMNH2 occurs only when the π-π interaction between FMNH2 and TNT is stronger than that between TNT and several key residues with aromatic rings. Finally, based on the competition mechanism, the formation of π-π stacking of TNT and FMNH2 can be successfully enabled by removing the aromatic ring of those key residues in enzymes that originally only transform TNT through the nitro group reduction. This testified the validity of the π-π interaction competition mechanism. This work theoretically clarifies the molecular mechanism of the first-step hydrogen-transfer reaction for the biotransformation of TNT by the OYE family. It is helpful to obtain the enzymes that can biodegrade TNT through the aromatic ring reduction.
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Affiliation(s)
- Zhilin Yang
- Institute of Chemical Materials, Chinese Academy of Engineering and Physics, 621900 Mianyang, China.
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Hsu DW, Wang TI, Huang DJ, Pao YJ, Lin YA, Cheng TW, Liang SH, Chen CY, Kao CM, Sheu YT, Chen CC. Copper promotes E. coli laccase-mediated TNT biotransformation and alters the toxicity of TNT metabolites toward Tigriopus japonicus. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2019; 173:452-460. [PMID: 30798189 DOI: 10.1016/j.ecoenv.2019.02.056] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 02/15/2019] [Accepted: 02/16/2019] [Indexed: 06/09/2023]
Abstract
Although laccase is involved in the biotransformation of 2,4,6-trinitrotoluene (TNT), little is known regarding the effect of E. coli laccase on TNT biotransformation. In this study, E. coli K12 served as the parental strain to construct a laccase deletion strain and two laccase-overexpressing strains. These E. coli strains were used to investigate the effect of laccase together with copper ions on the efficiency of TNT biotransformation, the variety of TNT biotransformation products generated and the toxicity of the TNT metabolites. The results showed that the laccase level was not relevant to TNT biotransformation in the soluble fraction of the culture medium. Conversely, TNT metabolites varied in the insoluble fraction analyzed by thin-layer chromatography (TLC). The insoluble fraction from the laccase-null strain showed fewer and relatively fainter spots than those detected in the wild-type and laccase-overexpressing strains, indicating that laccase expression levels were interrelated determinants of the varieties and amounts of TNT metabolites produced. In addition, the aquatic invertebrate Tigriopus japonicus was used to assess the toxicity of the TNT metabolites. The toxicity of the TNT metabolite mixture increased when the intracellular laccase level in strains increased or when purified E. coli recombinant Laccase (rLaccase) was added to the culture medium. Thus, our results suggest that laccase activity must be considered when performing microbial TNT remediation.
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Affiliation(s)
- Duen-Wei Hsu
- Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, Taiwan
| | - Tzu-I Wang
- Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, Taiwan
| | - Da-Ji Huang
- Department of Environmental Resources Management, Chia Nan University of Pharmacy & Science, Tainan, Taiwan
| | - Yu-Jie Pao
- Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, Taiwan
| | - Yuya A Lin
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Ting-Wen Cheng
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Shih-Hsiung Liang
- Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, Taiwan
| | - Chien-Yen Chen
- Department of Earth and Environmental Sciences, National Chung Cheng University, Chiayi, Taiwan
| | - Chih-Ming Kao
- Institute of Environmental Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Yih-Terng Sheu
- Institute of Environmental Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Chien-Cheng Chen
- Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, Taiwan.
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12
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Maksimova YG, Maksimov AY, Demakov VA. Biotechnological Approaches to the Bioremediation of an Environment Polluted with Trinitrotoluene. APPL BIOCHEM MICRO+ 2019. [DOI: 10.1134/s0003683818080045] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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13
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Miller AF, Park JT, Ferguson KL, Pitsawong W, Bommarius AS. Informing Efforts to Develop Nitroreductase for Amine Production. Molecules 2018; 23:molecules23020211. [PMID: 29364838 PMCID: PMC6017928 DOI: 10.3390/molecules23020211] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2017] [Revised: 01/03/2018] [Accepted: 01/12/2018] [Indexed: 12/19/2022] Open
Abstract
Nitroreductases (NRs) hold promise for converting nitroaromatics to aromatic amines. Nitroaromatic reduction rate increases with Hammett substituent constant for NRs from two different subgroups, confirming substrate identity as a key determinant of reactivity. Amine yields were low, but compounds yielding amines tend to have a large π system and electron withdrawing substituents. Therefore, we also assessed the prospects of varying the enzyme. Several different subgroups of NRs include members able to produce aromatic amines. Comparison of four NR subgroups shows that they provide contrasting substrate binding cavities with distinct constraints on substrate position relative to the flavin. The unique architecture of the NR dimer produces an enormous contact area which we propose provides the stabilization needed to offset the costs of insertion of the active sites between the monomers. Thus, we propose that the functional diversity included in the NR superfamily stems from the chemical versatility of the flavin cofactor in conjunction with a structure that permits tremendous active site variability. These complementary properties make NRs exceptionally promising enzymes for development for biocatalysis in prodrug activation and conversion of nitroaromatics to valuable aromatic amines. We provide a framework for identifying NRs and substrates with the greatest potential to advance.
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Affiliation(s)
- Anne-Frances Miller
- Department of Chemistry, University of Kentucky, Lexington, KY 40506-0055, USA.
| | - Jonathan T Park
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0100, USA.
| | - Kyle L Ferguson
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0100, USA.
| | - Warintra Pitsawong
- Department of Chemistry, University of Kentucky, Lexington, KY 40506-0055, USA.
| | - Andreas S Bommarius
- School of Chemical and Biomolecular Engineering, School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332-0100, USA.
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14
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Yang Z, Chen J, Zhou Y, Huang H, Xu D, Zhang C. Understanding the hydrogen transfer mechanism for the biodegradation of 2,4,6-trinitrotoluene catalyzed by pentaerythritol tetranitrate reductase: molecular dynamics simulations. Phys Chem Chem Phys 2018; 20:12157-12165. [DOI: 10.1039/c8cp00345a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The explosive 2,4,6-trinitrotoluene (TNT) is a highly toxic pollutant.
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Affiliation(s)
- Zhilin Yang
- Institute of Chemical Materials
- Chinese Academy of Engineering and Physics
- 621900 Mianyang
- China
| | - Junxian Chen
- MOE Key Laboratory of Green Chemistry & Technology
- College of Chemistry
- Sichuan University
- Chengdu
- P. R. China
| | - Yang Zhou
- Institute of Chemical Materials
- Chinese Academy of Engineering and Physics
- 621900 Mianyang
- China
| | - Hui Huang
- Institute of Chemical Materials
- Chinese Academy of Engineering and Physics
- 621900 Mianyang
- China
| | - Dingguo Xu
- MOE Key Laboratory of Green Chemistry & Technology
- College of Chemistry
- Sichuan University
- Chengdu
- P. R. China
| | - Chaoyang Zhang
- Institute of Chemical Materials
- Chinese Academy of Engineering and Physics
- 621900 Mianyang
- China
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15
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Khilyas IV, Lochnit G, Ilinskaya ON. Proteomic Analysis of 2,4,6-Trinitrotoluene Degrading Yeast Yarrowia lipolytica. Front Microbiol 2017; 8:2600. [PMID: 29312267 PMCID: PMC5744042 DOI: 10.3389/fmicb.2017.02600] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 12/13/2017] [Indexed: 11/28/2022] Open
Abstract
2,4,6-trinitrotoluene (TNT) is a common component of many explosives. The overproduction and extensive usage of TNT significantly contaminates the environment. TNT accumulates in soils and aquatic ecosystems and can primarily be destroyed by microorganisms. Current work is devoted to investigation of Yarrowia lipolytica proteins responsible for TNT transformation through the pathway leading to protonated Meisenheimer complexes and nitrite release. Here, we identified a unique set of upregulated membrane and cytosolic proteins of Y. lipolytica, which biosynthesis increased during TNT transformation through TNT-monohydride-Meisenheimer complexes in the first step of TNT degradation, through TNT-dihydride-Meisenheimer complexes in the second step, and the aromatic ring denitration and degradation in the last step. We established that the production of oxidoreductases, namely, NADH flavin oxidoreductases and NAD(P)+-dependent aldehyde dehydrogenases, as well as transferases was enhanced at all stages of the TNT transformation by Y. lipolytica. The up-regulation of several stress response proteins (superoxide dismutase, catalase, glutathione peroxidase, and glutathione S-transferase) was also detected. The involvement of intracellular nitric oxide dioxygenase in NO formation during nitrite oxidation was shown. Our results present at the first time the full proteome analysis of Y. lipolytica yeast, destructor of TNT.
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Affiliation(s)
- Irina V Khilyas
- Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, Kazan, Russia
| | - Guenter Lochnit
- Protein Analytics, Institute of Biochemistry, Faculty of Medicine, Justus Liebig University Giessen, Giessen, Germany
| | - Olga N Ilinskaya
- Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, Kazan, Russia
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16
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Chatterjee S, Deb U, Datta S, Walther C, Gupta DK. Common explosives (TNT, RDX, HMX) and their fate in the environment: Emphasizing bioremediation. CHEMOSPHERE 2017; 184:438-451. [PMID: 28618276 DOI: 10.1016/j.chemosphere.2017.06.008] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Revised: 05/10/2017] [Accepted: 06/03/2017] [Indexed: 06/07/2023]
Abstract
Explosive materials are energetic substances, when released into the environment, contaminate by posing toxic hazards to environment and biota. Throughout the world, soils are contaminated by such contaminants either due to manufacturing operations, military activities, conflicts of different levels, open burning/open detonation (OB/OD), dumping of munitions etc. Among different forms of chemical explosives, 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and octahydro-1,3,5,7-tetranitro- 1,3,5,7-tetrazocine (HMX) are most common. These explosives are highly toxic as USEPA has recommended restrictions for lifetime contact through drinking water. Although, there are several utilitarian aspects in anthropogenic activities, however, effective remediation of explosives is very important. This review article emphasizes the details of appropriate practices to ameliorate the contamination. Critical evaluation has also been made to encompass the recent knowledge and advancement about bioremediation and phytoremediation of explosives (especially TNT, RDX and HMX) along with the molecular mechanisms of biodegradation.
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Affiliation(s)
- Soumya Chatterjee
- Defence Research Laboratory, DRDO, Post Bag No. 02, Tezpur, 784001, Assam, India
| | - Utsab Deb
- Defence Research Laboratory, DRDO, Post Bag No. 02, Tezpur, 784001, Assam, India
| | - Sibnarayan Datta
- Defence Research Laboratory, DRDO, Post Bag No. 02, Tezpur, 784001, Assam, India
| | - Clemens Walther
- Gottfried Wilhelm Leibniz Universität Hannover, Institut für Radioökologie und Strahlenschutz (IRS), Herrenhäuser Str. 2, Gebäude 4113, 30419, Hannover, Germany
| | - Dharmendra K Gupta
- Gottfried Wilhelm Leibniz Universität Hannover, Institut für Radioökologie und Strahlenschutz (IRS), Herrenhäuser Str. 2, Gebäude 4113, 30419, Hannover, Germany.
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17
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Zhang L, Rylott EL, Bruce NC, Strand SE. Phytodetoxification of TNT by transplastomic tobacco (Nicotiana tabacum) expressing a bacterial nitroreductase. PLANT MOLECULAR BIOLOGY 2017; 95:99-109. [PMID: 28762129 DOI: 10.1007/s11103-017-0639-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 07/19/2017] [Indexed: 06/07/2023]
Abstract
KEY MESSAGE Expression of the bacterial nitroreductase gene, nfsI, in tobacco plastids conferred the ability to detoxify TNT. The toxic pollutant 2,4,6-trinitrotoluene (TNT) is recalcitrant to degradation in the environment. Phytoremediation is a potentially low cost remediation technique that could be applied to soil contaminated with TNT; however, progress is hindered by the phytotoxicity of this compound. Previous studies have demonstrated that plants transformed with the bacterial nitroreductase gene, nfsI have increased ability to tolerate and detoxify TNT. It has been proposed that plants engineered to express nfsI could be used to remediate TNT on military ranges, but this could require steps to mitigate transgene flow to wild populations. To address this, we have developed nfsI transplastomic tobacco (Nicotiana tabacum L.) to reduce pollen-borne transgene flow. Here we have shown that when grown on solid or liquid media, the transplastomic tobacco expressing nfsI were significantly more tolerant to TNT, produced increased biomass and removed more TNT from the media than untransformed plants. Additionally, transplastomic plants expressing nfsI regenerated with high efficiency when grown on medium containing TNT, suggesting that nfsI and TNT could together be used to provide a selectable screen for plastid transformation.
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Affiliation(s)
- Long Zhang
- Department of Civil and Environmental Engineering, University of Washington, Box 355014, Seattle, WA, 98195-5014, USA
| | | | - Neil C Bruce
- CNAP, Department of Biology, University of York, York, YO10 5DD, UK
| | - Stuart E Strand
- Department of Civil and Environmental Engineering, University of Washington, Box 355014, Seattle, WA, 98195-5014, USA.
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18
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Iman M, Sobati T, Panahi Y, Mobasheri M. Systems Biology Approach to Bioremediation of Nitroaromatics: Constraint-Based Analysis of 2,4,6-Trinitrotoluene Biotransformation by Escherichia coli. Molecules 2017; 22:E1242. [PMID: 28805729 PMCID: PMC6152126 DOI: 10.3390/molecules22081242] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 06/22/2017] [Accepted: 06/23/2017] [Indexed: 01/02/2023] Open
Abstract
Microbial remediation of nitroaromatic compounds (NACs) is a promising environmentally friendly and cost-effective approach to the removal of these life-threating agents. Escherichia coli (E. coli) has shown remarkable capability for the biotransformation of 2,4,6-trinitro-toluene (TNT). Efforts to develop E. coli as an efficient TNT degrading biocatalyst will benefit from holistic flux-level description of interactions between multiple TNT transforming pathways operating in the strain. To gain such an insight, we extended the genome-scale constraint-based model of E. coli to account for a curated version of major TNT transformation pathways known or evidently hypothesized to be active in E. coli in present of TNT. Using constraint-based analysis (CBA) methods, we then performed several series of in silico experiments to elucidate the contribution of these pathways individually or in combination to the E. coli TNT transformation capacity. Results of our analyses were validated by replicating several experimentally observed TNT degradation phenotypes in E. coli cultures. We further used the extended model to explore the influence of process parameters, including aeration regime, TNT concentration, cell density, and carbon source on TNT degradation efficiency. We also conducted an in silico metabolic engineering study to design a series of E. coli mutants capable of degrading TNT at higher yield compared with the wild-type strain. Our study, therefore, extends the application of CBA to bioremediation of nitroaromatics and demonstrates the usefulness of this approach to inform bioremediation research.
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Affiliation(s)
- Maryam Iman
- Chemical Injuries Research Center, Baqiyatallah University of Medical Sciences, 1477893855 Tehran, Iran.
- Department of Pharmaceutics, School of Pharmacy, Baqiyatallah University of Medical Sciences, 1477893855 Tehran, Iran.
| | - Tabassom Sobati
- Young Researchers and Elite Club, Islamic Azad University, 46115655 Tehran, Iran.
| | - Yunes Panahi
- Chemical Injuries Research Center, Baqiyatallah University of Medical Sciences, 1477893855 Tehran, Iran.
| | - Meysam Mobasheri
- Young Researchers and Elite Club, Islamic Azad University, 46115655 Tehran, Iran.
- Department of Biotechnology, Faculty of Advanced Sciences & Technology, Pharmaceutical Sciences Branch, Islamic Azad University (IAUPS), 194193311 Tehran, Iran.
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19
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Avila-Arias H, Avellaneda H, Garzón V, Rodríguez G, Arbeli Z, Garcia-Bonilla E, Villegas-Plazas M, Roldan F. Screening for biosurfactant production by 2,4,6-trinitrotoluene-transforming bacteria. J Appl Microbiol 2017; 123:401-413. [DOI: 10.1111/jam.13504] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 05/18/2017] [Accepted: 05/25/2017] [Indexed: 11/28/2022]
Affiliation(s)
- H. Avila-Arias
- Unidad de Saneamiento y Biotecnología Ambiental (USBA); Departamento de Biología; Facultad de Ciencias; Pontificia Universidad Javeriana; Bogotá Colombia
| | - H. Avellaneda
- Unidad de Saneamiento y Biotecnología Ambiental (USBA); Departamento de Biología; Facultad de Ciencias; Pontificia Universidad Javeriana; Bogotá Colombia
| | - V. Garzón
- Unidad de Saneamiento y Biotecnología Ambiental (USBA); Departamento de Biología; Facultad de Ciencias; Pontificia Universidad Javeriana; Bogotá Colombia
| | - G. Rodríguez
- Unidad de Saneamiento y Biotecnología Ambiental (USBA); Departamento de Biología; Facultad de Ciencias; Pontificia Universidad Javeriana; Bogotá Colombia
| | - Z. Arbeli
- Unidad de Saneamiento y Biotecnología Ambiental (USBA); Departamento de Biología; Facultad de Ciencias; Pontificia Universidad Javeriana; Bogotá Colombia
| | - E. Garcia-Bonilla
- Unidad de Saneamiento y Biotecnología Ambiental (USBA); Departamento de Biología; Facultad de Ciencias; Pontificia Universidad Javeriana; Bogotá Colombia
| | - M. Villegas-Plazas
- Unidad de Saneamiento y Biotecnología Ambiental (USBA); Departamento de Biología; Facultad de Ciencias; Pontificia Universidad Javeriana; Bogotá Colombia
| | - F. Roldan
- Unidad de Saneamiento y Biotecnología Ambiental (USBA); Departamento de Biología; Facultad de Ciencias; Pontificia Universidad Javeriana; Bogotá Colombia
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20
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Liang SH, Hsu DW, Lin CY, Kao CM, Huang DJ, Chien CC, Chen SC, Tsai IJ, Chen CC. Enhancement of microbial 2,4,6-trinitrotoluene transformation with increased toxicity by exogenous nutrient amendment. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2017; 138:39-46. [PMID: 28006730 DOI: 10.1016/j.ecoenv.2016.12.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 11/18/2016] [Accepted: 12/08/2016] [Indexed: 06/06/2023]
Abstract
In this study, the bacterial strain Citrobacter youngae strain E4 was isolated from 2,4,6-trinitrotoluene (TNT)-contaminated soil and used to assess the capacity of TNT transformation with/without exogenous nutrient amendments. C. youngae E4 poorly degraded TNT without an exogenous amino nitrogen source, whereas the addition of an amino nitrogen source considerably increased the efficacy of TNT transformation in a dose-dependent manner. The enhanced TNT transformation of C. youngae E4 was mediated by increased cell growth and up-regulation of TNT nitroreductases, including NemA, NfsA and NfsB. This result indicates that the increase in TNT transformation by C. youngae E4 via nitrogen nutrient stimulation is a cometabolism process. Consistently, TNT transformation was effectively enhanced when C. youngae E4 was subjected to a TNT-contaminated soil slurry in the presence of an exogenous amino nitrogen amendment. Thus, effective enhancement of TNT transformation via the coordinated inoculation of the nutrient-responsive C. youngae E4 and an exogenous nitrogen amendment might be applicable for the remediation of TNT-contaminated soil. Although the TNT transformation was significantly enhanced by C. youngae E4 in concert with biostimulation, the 96-h LC50 value of the TNT transformation product mixture on the aquatic invertebrate Tigriopus japonicas was higher than the LC50 value of TNT alone. Our results suggest that exogenous nutrient amendment can enhance microbial TNT transformation; however, additional detoxification processes may be needed due to the increased toxicity after reduced TNT transformation.
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Affiliation(s)
- Shih-Hsiung Liang
- Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, Taiwan
| | - Duen-Wei Hsu
- Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, Taiwan
| | - Chia-Ying Lin
- Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, Taiwan
| | - Chih-Ming Kao
- Institute of Environmental Engineering, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Da-Ji Huang
- Department of Environmental Resources Management, Chia Nan University of Pharmacy & Science, Tainan, Taiwan
| | - Chih-Ching Chien
- Graduate School of Biotechnology and Bioengineering, Yuan Ze University, Chung-Li, Taiwan
| | - Ssu-Ching Chen
- Department of Life Sciences, National Central University, Taoyuan, Taiwan
| | | | - Chien-Cheng Chen
- Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, Taiwan.
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21
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Lotufo GR, Belden JB, Fisher JC, Chen SF, Mowery RA, Chambliss CK, Rosen G. Accumulation and depuration of trinitrotoluene and related extractable and nonextractable (bound) residues in marine fish and mussels. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2016; 210:129-136. [PMID: 26708767 DOI: 10.1016/j.envpol.2015.11.049] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 11/25/2015] [Accepted: 11/27/2015] [Indexed: 06/05/2023]
Abstract
To determine if trinitrotoluene (TNT) forms nonextractable residues in mussels (Mytilus galloprovincialis) and fish (Cyprinodon variegatus) and to measure the relative degree of accumulation as compared to extractable TNT and its major metabolites, organisms were exposed to water fortified with (14)C-TNT. After 24 h, nonextractable residues made up 75% (mussel) and 83% (fish) while TNT accounted for 2% of total radioactivity. Depuration half-lives for extractable TNT, aminodinitrotoluenes (ADNTs) and diaminonitrotoluenes (DANTs) were fast initially (<0.5 h), but slower for nonextractable residues. Nonextractable residues from organisms were identified as ADNTs and DANTs using 0.1 M HCL for solubilization followed by liquid chromatography-tandem mass spectrometry. Recovered metabolites only accounted for a small fraction of the bound residue quantified using a radiotracer likely because of low extraction or hydrolysis efficiency or alternative pathways of incorporation of radiolabel into tissue.
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Affiliation(s)
- Guilherme R Lotufo
- U.S. Army Engineer Research and Development Center, 3909 Halls Ferry Road, Vicksburg, MS 39180, USA.
| | - Jason B Belden
- Department of Integrative Biology, Oklahoma State University, Stillwater OK 74078, USA
| | - Jonathon C Fisher
- Department of Natural Sciences, Northwestern State University, Tahlequah, OK 74464, USA
| | - Shou-Feng Chen
- Department of Chemistry, Baylor University, Waco, TX 76798, USA
| | | | | | - Gunther Rosen
- Space and Naval Warfare (SPAWAR) Systems Center Pacific, 53475 Strothe Rd., San Diego, CA 92152, USA
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22
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Shinkai Y, Nishihara Y, Amamiya M, Wakayama T, Li S, Kikuchi T, Nakai Y, Shimojo N, Kumagai Y. NADPH-cytochrome P450 reductase-mediated denitration reaction of 2,4,6-trinitrotoluene to yield nitrite in mammals. Free Radic Biol Med 2016; 91:178-87. [PMID: 26454083 DOI: 10.1016/j.freeradbiomed.2015.09.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Revised: 09/01/2015] [Accepted: 09/03/2015] [Indexed: 10/22/2022]
Abstract
While the biodegradation of 2,4,6-trinitrotoluene (TNT) via the release of nitrite is well established, mechanistic details of the reaction in mammals are unknown. To address this issue, we attempted to identify the enzyme from rat liver responsible for the production of nitrite from TNT. A NADPH-cytochrome P450 reductase (P450R) was isolated and identified from rat liver microsomes as the enzyme responsible for not only the release of nitrite from TNT but also formation of superoxide and 4-hydroxyamino-2,6-dinitrotoluene (4-HADNT) under aerobic conditions. In this context, reactive oxygen species generated during P450R-catalyzed TNT reduction were found to be, at least in part, a mediator for the production of 4-HADNT from TNT via formation of 4-nitroso-2,6-dinitrotoluene. P450R did not catalyze the formation of the hydride-Meisenheimer complex (H(-)-TNT) that is thought to be an intermediate for nitrite release from TNT. Furthermore, in a time-course experiment, 4-HADNT formation reached a plateau level and then declined during the reaction between TNT and P450R with NADPH, while the release of nitrite was subjected to a lag period. Notably, the produced 4-HADNT can react with the parent compound TNT to produce nitrite and dimerized products via formation of a Janovsky complex. Our results demonstrate for the first time that P450R-mediated release of nitrite from TNT results from the process of chemical interaction of TNT and its 4-electron reduction metabolite 4-HADNT.
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Affiliation(s)
- Yasuhiro Shinkai
- Environmental Biology Laboratory, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan; Graduate School of Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Yuya Nishihara
- Graduate School of Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Masahiro Amamiya
- Graduate School of Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Toshihiko Wakayama
- Graduate School of Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Song Li
- Doctoral Program in Medical Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Tomohiro Kikuchi
- Graduate School of Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Yumi Nakai
- Application and Research Center, JEOL Ltd., 3-1-2 Musashino, Akishima, Tokyo 196-8558, Japan
| | - Nobuhiro Shimojo
- Graduate School of Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan; Doctoral Program in Medical Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Yoshito Kumagai
- Environmental Biology Laboratory, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan; Graduate School of Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan; Doctoral Program in Medical Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
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Khan MI, Lee J, Yoo K, Kim S, Park J. Improved TNT detoxification by starch addition in a nitrogen-fixing Methylophilus-dominant aerobic microbial consortium. JOURNAL OF HAZARDOUS MATERIALS 2015; 300:873-881. [PMID: 26342802 DOI: 10.1016/j.jhazmat.2015.08.032] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 07/24/2015] [Accepted: 08/17/2015] [Indexed: 06/05/2023]
Abstract
In this study, a novel aerobic microbial consortium for the complete detoxification of 2,4,6-trinitrotoluene (TNT) was developed using starch as a slow-releasing carbon source under nitrogen-fixing conditions. Aerobic TNT biodegradation coupled with microbial growth was effectively stimulated by the co-addition of starch and TNT under nitrogen-fixing conditions. The addition of starch with TNT led to TNT mineralization via ring cleavage without accumulation of any toxic by-products, indicating improved TNT detoxification by the co-addition of starch and TNT. Pyrosequencing targeting the bacterial 16S rRNA gene suggested that Methylophilus and Pseudoxanthomonas population were significantly stimulated by the co-addition of starch and TNT and that the Methylophilus population became predominant in the consortium. Together with our previous study regarding starch-stimulated RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) degradation (Khan et al., J. Hazard. Mater. 287 (2015) 243-251), this work suggests that the co-addition of starch with a target explosive is an effective way to stimulate aerobic explosive degradation under nitrogen-fixing conditions for enhancing explosive detoxification.
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Affiliation(s)
- Muhammad Imran Khan
- Department of Civil and Environmental Engineering, College of Engineering, Yonsei University, Seoul 120-749, Republic of Korea; Department of Agronomy, University of Agriculture, Faisalabad 38040, Pakistan
| | - Jaejin Lee
- Department of Civil and Environmental Engineering, College of Engineering, Yonsei University, Seoul 120-749, Republic of Korea
| | - Keunje Yoo
- Department of Civil and Environmental Engineering, College of Engineering, Yonsei University, Seoul 120-749, Republic of Korea
| | - Seonghoon Kim
- Department of Civil and Environmental Engineering, College of Engineering, Yonsei University, Seoul 120-749, Republic of Korea
| | - Joonhong Park
- Department of Civil and Environmental Engineering, College of Engineering, Yonsei University, Seoul 120-749, Republic of Korea.
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24
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Ziganshin AM, Ziganshina EE, Byrne J, Gerlach R, Struve E, Biktagirov T, Rodionov A, Kappler A. Fe(III) mineral reduction followed by partial dissolution and reactive oxygen species generation during 2,4,6-trinitrotoluene transformation by the aerobic yeast Yarrowia lipolytica. AMB Express 2015; 5:8. [PMID: 25852985 PMCID: PMC4314830 DOI: 10.1186/s13568-014-0094-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 12/29/2014] [Indexed: 11/23/2022] Open
Abstract
Understanding the factors that influence pollutant transformation in the presence of ferric (oxyhydr)oxides is crucial to the efficient application of different remediation strategies. In this study we determined the effect of goethite, hematite, magnetite and ferrihydrite on the transformation of 2,4,6-trinitrotoluene (TNT) by Yarrowia lipolytica AN-L15. The presence of ferric (oxyhydr)oxides led to a small decrease in the rate of TNT removal. In all cases, a significant release of NO2− from TNT and further NO2− oxidation to NO3− was observed. A fraction of the released NO2− was abiotically decomposed to NO and NO2, and then NO was likely oxidized abiotically to NO2 by O2. ESR analysis revealed the generation of superoxide in the culture medium; its further protonation at low pH resulted in the formation of hydroperoxyl radical. Presumably, a fraction of NO released during TNT degradation reacted with superoxide and formed peroxynitrite, which was further rearranged to NO3− at the acidic pH values observed in this study. A transformation and reduction of ferric (oxyhydr)oxides followed by partial dissolution (in the range of 7–86% of the initial Fe(III)) were observed in the presence of cells and TNT. Mössbauer spectroscopy showed some minor changes for goethite, magnetite and ferrihydrite samples during their incubation with Y. lipolytica and TNT. This study shows that i) reactive oxygen and nitrogen species generated during TNT transformation by Y. lipolytica participate in the abiotic conversion of TNT and ii) the presence of iron(III) minerals leads to a minor decrease in TNT transformation.
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Solyanikova IP, Robota IV, Mazur DM, Lebedev AT, Golovleva LA. Application of Bacillus sp. strain VT-8 for decontamination of TNT-polluted sites. Microbiology (Reading) 2014. [DOI: 10.1134/s0026261714050257] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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26
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Darvishi Harzevili F. Yarrowia lipolytica in Biotechnological Applications. SPRINGERBRIEFS IN MICROBIOLOGY 2014. [DOI: 10.1007/978-3-319-06437-6_2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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27
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Erkelens M, Adetutu EM, Taha M, Tudararo-Aherobo L, Antiabong J, Provatas A, Ball AS. Sustainable remediation--the application of bioremediated soil for use in the degradation of TNT chips. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2012; 110:69-76. [PMID: 22728982 DOI: 10.1016/j.jenvman.2012.05.022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 05/19/2012] [Accepted: 05/26/2012] [Indexed: 06/01/2023]
Abstract
Environmental contamination by TNT (2,4,6 trinitrotoluene), historically used in civilian industries and the military as an explosive is of great concern due to its toxicity. Scientific studies have however shown that TNT is susceptible to microbial transformation. The aim of this study was to assess the potential of a previously bioremediated hydrocarbon contaminated soil (PBR) to increase TNT degradation rates. This was investigated by adding TNT chips to PBR and uncontaminated soils (PNC) in laboratory based studies (up to 16 weeks). Residual TNT chip analysis showed greater TNT degradation in PBR soils (70%) and significantly higher metabolic rates (4.5 fold increase in cumulative CO(2) levels) than in PNC soils (30%). Molecular analysis (PCR-DGGE-cluster analysis) showed substantial shifts in soil microbial communities associated with TNT contamination between day 0 and week 4 especially in PBR soils. Bacterial communities appeared to be more sensitive to TNT contamination than fungal communities in both soils. Quantitative PCR analysis showed ~3 fold increase in the abundance of nitroreductase genes (pnrA) in PBR soils with a gradual reduction in community evenness (Pareto-Lorenz curves) in contrast to PNC soils. These results suggest that microbial response to TNT contamination was dependent on the history of soil use. The results also confirm that the microbial potential of waste soils such as PBR soil (usually disposed of via landfill) can be successfully used for accelerated TNT chip degradation. This promotes sustainable re-use of waste soils extending the life span of landfill sites.
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Affiliation(s)
- Mason Erkelens
- School of Biological Sciences, Flinders University of South Australia, Sturt Road, Bedford Park, Adelaide, GPO Box 2100, Adelaide, SA 5001, Australia
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Isayev O, Crespo-Hernández CE, Gorb L, Hill FC, Leszczynski J. In silico structure-function analysis of E. cloacae nitroreductase. Proteins 2012; 80:2728-41. [PMID: 22865652 DOI: 10.1002/prot.24157] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 04/26/2012] [Accepted: 07/05/2012] [Indexed: 01/18/2023]
Abstract
Reduction, catalyzed by the bacterial nitroreductases, is the quintessential first step in the biodegradation of a variety of nitroaromatic compounds from contaminated waters and soil. The Enterobacter cloacae nitroreductase (EcNR) enzyme is considered as a prospective biotechnological tool for bioremediation of hazardous nitroaromatic compounds. Using diverse computational methods, we obtain insights into the structural basis of activity and mechanism of its function. We have performed molecular dynamics simulation of EcNR in three different states (free EcNR in oxidized form, fully reduced EcNR with benzoate inhibitor and fully reduced EcNR with nitrobenzene) in explicit solvent and with full electrostatics. Principal Component Analysis (PCA) of the variance-covariance matrix showed that the complexed nitroreductase becomes more flexible overall upon complexation, particularly helix H6, in the vicinity of the binding site. A multiple sequence alignment was also constructed in order to examine positional constraints on substitution in EcNR. Five regions which are highly conserved within the flavin mononucleotide (FMN) binding site were identified. Obtained results and their implications for EcNR functioning are discussed, and new plausible mechanism has been proposed.
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Affiliation(s)
- Olexandr Isayev
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106, USA.
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29
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Fernández M, Duque E, Pizarro-Tobías P, Van Dillewijn P, Wittich RM, Ramos JL. Microbial responses to xenobiotic compounds. Identification of genes that allow Pseudomonas putida KT2440 to cope with 2,4,6-trinitrotoluene. Microb Biotechnol 2011; 2:287-94. [PMID: 21261922 PMCID: PMC3815848 DOI: 10.1111/j.1751-7915.2009.00085.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Pseudomonas putida KT2440 grows in M9 minimal medium with glucose in the presence of 2,4,6‐trinitrotoluene (TNT) at a similar rate than in the absence of TNT, although global transcriptional analysis using DNA microarrays revealed that TNT exerts some stress. Response to TNT stress is regulated at the transcriptional level, as significant changes in the level of expression of 65 genes were observed. Of these genes, 39 appeared upregulated, and 26 were downregulated. The identity of upregulated genes suggests that P. putida uses two kinds of strategies to overcome TNT toxicity: (i) induction of genes encoding nitroreductases and detoxification‐related enzymes (pnrA, xenD, acpD) and (ii) induction of multidrug efflux pump genes (mexEF/oprN) to reduce intracellular TNT concentrations. Mutants of 13 up‐ and 7 downregulated genes were analysed with regards to TNT toxicity revealing the role of the MexE/MexF/OprN pump and a putative isoquinoline 1‐oxidoreductase in tolerance to TNT. The ORF PP1232 whose transcriptional level did not change in response to TNT affected growth in the presence of nitroaromatic compounds and it was found in a screening of 4000 randomly generated mutants.
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Affiliation(s)
- Matilde Fernández
- Bio-Iliberis Research and Development, Edificio BIC, Parque Tecnológico de Ciencias de la Salud, E-18100 Armilla, Granada, Spain
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Perumbakkam S, Mitchell EA, Craig AM. Changes to the rumen bacterial population of sheep with the addition of 2,4,6-trinitrotoluene to their diet. Antonie van Leeuwenhoek 2010; 99:231-40. [PMID: 20607404 DOI: 10.1007/s10482-010-9481-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2010] [Accepted: 06/24/2010] [Indexed: 11/27/2022]
Abstract
Previous work has shown that bacterial isolates from the sheep rumen are capable of detoxifying 2,4,6-trinitrotoluene (TNT) into polar constituents. In this study, the dietary effects of TNT on the sheep rumen microbial community were evaluated using molecular microbiology ecology tools. Rumen samples were collected from sheep fed with and without TNT added to their diet, genomic DNA was extracted, and the 16S rRNA-V3 gene marker was used to quantify changes in the microbial population in the rumen. Control and treatment samples yielded 533 sequences. Phylogenetic analyses were performed to determine the microbial changes between the two conditions. Results indicated the predominant bacterial populations present in the rumen were comprised of the phyla Firmicutes and Bacteroidetes, irrespective of presence/absence of TNT in the diet. Significant differences (P < 0.001) were found between the community structure of the bacteria under TNT (-) and TNT (+) diets. Examination of the TNT (+) diet showed an increase in the clones belonging to family Ruminococcaceae, which have previously been shown to degrade TNT in pure culture experiments.
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Affiliation(s)
- Sudeep Perumbakkam
- Department of Environmental and Molecular Toxicology, Oregon State University, Corvallis, OR 97331, USA
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31
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Biochemistry of microbial degradation of hexachlorocyclohexane and prospects for bioremediation. Microbiol Mol Biol Rev 2010; 74:58-80. [PMID: 20197499 DOI: 10.1128/mmbr.00029-09] [Citation(s) in RCA: 244] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lindane, the gamma-isomer of hexachlorocyclohexane (HCH), is a potent insecticide. Purified lindane or unpurified mixtures of this and alpha-, beta-, and delta-isomers of HCH were widely used as commercial insecticides in the last half of the 20th century. Large dumps of unused HCH isomers now constitute a major hazard because of their long residence times in soil and high nontarget toxicities. The major pathway for the aerobic degradation of HCH isomers in soil is the Lin pathway, and variants of this pathway will degrade all four of the HCH isomers although only slowly. Sequence differences in the primary LinA and LinB enzymes in the pathway play a key role in determining their ability to degrade the different isomers. LinA is a dehydrochlorinase, but little is known of its biochemistry. LinB is a hydrolytic dechlorinase that has been heterologously expressed and crystallized, and there is some understanding of the sequence-structure-function relationships underlying its substrate specificity and kinetics, although there are also some significant anomalies. The kinetics of some LinB variants are reported to be slow even for their preferred isomers. It is important to develop a better understanding of the biochemistries of the LinA and LinB variants and to use that knowledge to build better variants, because field trials of some bioremediation strategies based on the Lin pathway have yielded promising results but would not yet achieve economic levels of remediation.
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Detection of 2,4,6-trinitrotoluene-utilizing anaerobic bacteria by 15N and 13C incorporation. Appl Environ Microbiol 2010; 76:1695-8. [PMID: 20081008 DOI: 10.1128/aem.02274-09] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
2,4,6-Trinitrotoluene ((15)N or (13)C labeled) was added to Norfolk Harbor sediments to test whether anaerobic bacteria use TNT for growth. Stable-isotope probing (SIP)-terminal restriction fragment length polymorphism (TRFLP) detected peaks in the [(15)N]TNT cultures (60, 163, and 168 bp). The 60-bp peak was also present in the [(13)C]TNT cultures and was related to Lysobacter taiwanensis.
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Makris KC, Sarkar D, Datta R. Coupling indigenous biostimulation and phytoremediation for the restoration of 2,4,6-trinitrotoluene-contaminated sites. ACTA ACUST UNITED AC 2010; 12:399-403. [DOI: 10.1039/b908162c] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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34
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Sagi-Ben Moshe S, Ronen Z, Dahan O, Weisbrod N, Groisman L, Adar E, Nativ R. Sequential biodegradation of TNT, RDX and HMX in a mixture. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2009; 157:2231-2238. [PMID: 19428165 DOI: 10.1016/j.envpol.2009.04.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2008] [Revised: 04/03/2009] [Accepted: 04/06/2009] [Indexed: 05/27/2023]
Abstract
We describe TNT's inhibition of RDX and HMX anaerobic degradation in contaminated soil containing indigenous microbial populations. Biodegradation of RDX or HMX alone was markedly faster than their degradation in a mixture with TNT, implying biodegradation inhibition by the latter. The delay caused by the presence of TNT continued even after its disappearance and was linked to the presence of its intermediate, tetranitroazoxytoluene. PCR-DGGE analysis of cultures derived from the soil indicated a clear reduction in microbial biomass and diversity with increasing TNT concentration. At high-TNT concentrations (30 and 90 mg/L), only a single band, related to Clostridium nitrophenolicum, was observed after 3 days of incubation. We propose that the mechanism of TNT inhibition involves a cytotoxic effect on the RDX- and HMX-degrading microbial population. TNT inhibition in the top active soil can therefore initiate rapid transport of RDX and HMX to the less active subsurface and groundwater.
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Affiliation(s)
- S Sagi-Ben Moshe
- Department of Soil & Water Sciences, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100, Israel
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Wittich RM, Ramos JL, van Dillewijn P. Microorganisms and explosives: mechanisms of nitrogen release from TNT for use as an N-source for growth. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2009; 43:2773-2776. [PMID: 19475948 DOI: 10.1021/es803372n] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Unstable reduced derivatives of 2,4,6-trinitrotoluene (TNT) produced by microorganisms have been found to release nitrite by rearomatization and/or condensation. Here, we present further information regarding the novel mechanism of the condensation of reactive hydroxylaminodinitrotoluene and the Meisenheimer dihydride complex of TNT to produce two secondary diarylamine isomers. Using uniformly 15N-labeled (15N3) TNT, we show that the nitrite is being released by the condensation reaction and, also under environmental conditions, will originate from the microbiologically generated dihydride complex.
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Affiliation(s)
- Rolf-Michael Wittich
- Departamento de Protección Ambiental, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Calle Profesor Albareda 1, E-18008 Granada, Spain.
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Singh R, Manjunatha U, Boshoff HIM, Ha YH, Niyomrattanakit P, Ledwidge R, Dowd CS, Lee IY, Kim P, Zhang L, Kang S, Keller TH, Jiricek J, Barry CE. PA-824 kills nonreplicating Mycobacterium tuberculosis by intracellular NO release. Science 2008; 322:1392-5. [PMID: 19039139 PMCID: PMC2723733 DOI: 10.1126/science.1164571] [Citation(s) in RCA: 465] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Bicyclic nitroimidazoles, including PA-824, are exciting candidates for the treatment of tuberculosis. These prodrugs require intracellular activation for their biological function. We found that Rv3547 is a deazaflavin-dependent nitroreductase (Ddn) that converts PA-824 into three primary metabolites; the major one is the corresponding des-nitroimidazole (des-nitro). When derivatives of PA-824 were used, the amount of des-nitro metabolite formed was highly correlated with anaerobic killing of Mycobacterium tuberculosis (Mtb). Des-nitro metabolite formation generated reactive nitrogen species, including nitric oxide (NO), which are the major effectors of the anaerobic activity of these compounds. Furthermore, NO scavengers protected the bacilli from the lethal effects of the drug. Thus, these compounds may act as intracellular NO donors and could augment a killing mechanism intrinsic to the innate immune system.
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Affiliation(s)
- Ramandeep Singh
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Ujjini Manjunatha
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
- Novartis Institute for Tropical Diseases, 138670 Singapore
| | - Helena I. M. Boshoff
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Young Hwan Ha
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | | | - Richard Ledwidge
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Cynthia S. Dowd
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Ill Young Lee
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Pilho Kim
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Liang Zhang
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | - Sunhee Kang
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
| | | | - Jan Jiricek
- Novartis Institute for Tropical Diseases, 138670 Singapore
| | - Clifton E. Barry
- Tuberculosis Research Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892, USA
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Van Dillewijn P, Couselo JL, Corredoira E, Delgado A, Wittich RM, Ballester A, Ramos JL. Bioremediation of 2,4,6-trinitrotoluene by bacterial nitroreductase expressing transgenic aspen. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2008; 42:7405-7410. [PMID: 18939578 DOI: 10.1021/es801231w] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Trees belonging to the genus Populus are often used for phytoremediation due to their deep root formation, fast growth and high transpiration rates. Here, we study the capacity of transgenic hybrid aspen (Populus tremula x tremuloides var. Etropole) which expresses the bacterial nitroreductase gene, pnrA, to tolerate and take-up greater amounts of the toxic and recalcitrant explosive, 2,4,6-trinitrotoluene (TNT) from contaminated waters and soil. Transgenic aspen tolerate up to 57 mg TNT/L in hydroponic media and more than 1000 mg TNT/ kg soil, whereas the parental aspen could not endure in hydroponic culture with more than 11 mg TNT/L or soil with more than 500 mg TNT/kg. Likewise, the phytotoxicological limit for transgenic plants to a constant concentration of TNT was 20 mg TNT/L while wild-type plants only tolerated 10 mg TNT/L. Transgenic plants also showed improved uptake of TNT over wild-type plants when the original TNT concentration was above 35 mg TNT/L in liquid media or 750 mg TNT/kg in soil. Assays with 13C-labeled TNT show rapid adsorption of TNT to the root surface followed by a slower entrance rate into the plant. Most of the 13C-carbon from the labeled TNT taken up bythe plant (> 95%) remains in the root with little translocation to the stem. Altogether, transgenic aspen expressing pnrA are highly interesting for phytoremediation applications on contaminated soil and underground aquifers.
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Affiliation(s)
- Pieter Van Dillewijn
- Estacioín Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Department of Environmental Protection, Granada, Spain
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Subfunctionality of hydride transferases of the old yellow enzyme family of flavoproteins of Pseudomonas putida. Appl Environ Microbiol 2008; 74:6703-8. [PMID: 18791012 DOI: 10.1128/aem.00386-08] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To investigate potential complementary activities of multiple enzymes belonging to the same family within a single microorganism, we chose a set of Old Yellow Enzyme (OYE) homologs of Pseudomonas putida. The physiological function of these enzymes is not well established; however, an activity associated with OYE family members from different microorganisms is their ability to reduce nitroaromatic compounds. Using an in silico approach, we identified six OYE homologs in P. putida KT2440. Each gene was subcloned into an expression vector, and each corresponding gene product was purified to homogeneity prior to in vitro analysis for its catalytic activity against 2,4,6-trinitrotoluene (TNT). One of the enzymes, called XenD, lacked in vitro activity, whereas the other five enzymes demonstrated type I hydride transferase activity and reduced the nitro groups of TNT to hydroxylaminodinitrotoluene derivatives. XenB has the additional ability to reduce the aromatic ring of TNT to produce Meisenheimer complexes, defined as type II hydride transferase activity. The condensations of the primary products of type I and type II hydride transferases react with each other to yield diarylamines and nitrite; the latter can be further reduced to ammonium and serves as a nitrogen source for microorganisms in vivo.
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Type II hydride transferases from different microorganisms yield nitrite and diarylamines from polynitroaromatic compounds. Appl Environ Microbiol 2008; 74:6820-3. [PMID: 18791007 DOI: 10.1128/aem.00388-08] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Homogenous preparations of XenB of Pseudomonas putida, pentaerythritol tetranitrate reductase of Enterobacter cloacae, and N-ethylmaleimide reductase of Escherichia coli, all type II hydride transferases of the Old Yellow Enzyme family of flavoproteins, are shown to reduce the polynitroaromatic compound 2,4,6-trinitrotoluene (TNT). The reduction of this compound yields hydroxylaminodinitrotoluenes and Meisenheimer dihydride complexes, which, upon condensation, yield stoichiometric amounts of nitrite and diarylamines, implying that type II hydride transferases are responsible for TNT denitration, a process with important environmental implications for TNT remediation.
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