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Karanasios E, Tsiropoulos NG, Karpouzas DG. On-farm biopurification systems for the depuration of pesticide wastewaters: recent biotechnological advances and future perspectives. Biodegradation 2012; 23:787-802. [PMID: 23054187 DOI: 10.1007/s10532-012-9571-8] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2012] [Accepted: 06/27/2012] [Indexed: 11/29/2022]
Abstract
Point source contamination of natural water resources by pesticides constitutes a serious problem and on-farm biopurification systems (BPS) were introduced to resolve it. This paper reviews the processes and parameters controlling BPS depuration efficiency and reports on recent biotechnological advances which have been used for enhancing BPS performance. Biomixture composition and water management are the two factors which either individually or through their interactions control the depuration performance of BPS. Which process (biodegradation or adsorption) will dominate pesticides dissipation in BPS depends on biomixture composition and the physicochemical properties of the pesticides. Biotechnological interventions such as augmentation with pesticide-degrading microbes or pesticide-primed matrices have resulted in enhanced biodegradation performance of BPS. Despite all these advancement in BPS research, there are still several issues which should be resolved to facilitate their full implementation. Safe handling and disposal of the spent biomixture is a key practical issue which needs further research. The use of BPS for the depuration of wastewaters from post-farm activities such as postharvest treatment of fruits should be a priority research issue considering the lack of alternative treatment systems. However, the key point hampering optimization of BPS is the lack of fundamental knowledge on BPS microbiology. The use of advanced molecular and biochemical methods in BPS would shed light into this issue in the future.
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Affiliation(s)
- Evangelos Karanasios
- Department of Pesticide Control and Phytopharmacy, Benaki Phytopathological Institute, Athens, Greece
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52
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Sasikala C, Jiwal S, Rout P, Ramya M. Biodegradation of chlorpyrifos by bacterial consortium isolated from agriculture soil. World J Microbiol Biotechnol 2011; 28:1301-8. [DOI: 10.1007/s11274-011-0879-z] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Accepted: 08/31/2011] [Indexed: 10/17/2022]
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53
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Kreutzweiser D, Thompson D, Grimalt S, Chartrand D, Good K, Scarr T. Environmental safety to decomposer invertebrates of azadirachtin (neem) as a systemic insecticide in trees to control emerald ash borer. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2011; 74:1734-1741. [PMID: 21531021 DOI: 10.1016/j.ecoenv.2011.04.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Revised: 04/12/2011] [Accepted: 04/16/2011] [Indexed: 05/30/2023]
Abstract
The non-target effects of an azadirachtin-based systemic insecticide used for control of wood-boring insect pests in trees were assessed on litter-dwelling earthworms, leaf-shredding aquatic insects, and microbial communities in terrestrial and aquatic microcosms. The insecticide was injected into the trunks of ash trees at a rate of 0.2 gazadirachtin cm(-1) tree diameter in early summer. At the time of senescence, foliar concentrations in most (65%) leaves where at or below detection (<0.01 mg kg(-1) total azadirachtin) and the average concentration among leaves overall at senescence was 0.19 mg kg(-1). Leaves from the azadirachtin-treated trees at senescence were added to microcosms and responses by test organisms were compared to those in microcosms containing leaves from non-treated ash trees (controls). No significant reductions were detected among earthworm survival, leaf consumption rates, growth rates, or cocoon production, aquatic insect survival and leaf consumption rates, and among terrestrial and aquatic microbial decomposition of leaf material in comparison to controls. In a further set of microcosm tests containing leaves from intentional high-dose trees, the only significant, adverse effect detected was a reduction in microbial decomposition of leaf material, and only at the highest test concentration (∼6 mg kg(-1)). Results indicated no significant adverse effects on litter-dwelling earthworms or leaf-shredding aquatic insects at concentrations up to at least 30 × the expected field concentrations at operational rates, and at 6 × expected field concentrations for adverse effects on microbial decomposition. We conclude that when azadirachtin is used as a systemic insecticide in trees for control of insect pests such as the invasive wood-boring beetle, emerald ash borer, resultant foliar concentrations in senescent leaf material are likely to pose little risk of harm to decomposer invertebrates.
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Affiliation(s)
- David Kreutzweiser
- Canadian Forest Service, Natural Resources Canada, 1219 Queen St. East, Sault Ste. Marie, Ontario, Canada P6A 2E5.
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Abo-Amer AE. Characterization of a strain of Pseudomonas putida isolated from agricultural soil that degrades cadusafos (an organophosphorus pesticide). World J Microbiol Biotechnol 2011; 28:805-14. [DOI: 10.1007/s11274-011-0873-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Accepted: 08/20/2011] [Indexed: 10/17/2022]
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Kernchen RJ. Enzyme Stabilization in Nanostructured Materials, for Use in Organophosphorus Nerve Agent Detoxification and Prophylaxis. BIODEFENCE 2011. [DOI: 10.1007/978-94-007-0217-2_14] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Bergström L, Börjesson E, Stenström J. Laboratory and lysimeter studies of glyphosate and aminomethylphosphonic acid in a sand and a clay soil. JOURNAL OF ENVIRONMENTAL QUALITY 2011; 40:98-108. [PMID: 21488498 DOI: 10.2134/jeq2010.0179] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Indexed: 05/23/2023]
Abstract
Due to the increasing concern about the appearance of glyphosate [N-(phosphonomethyl)glycine] and its major metabolite aminomethylphosphonic acid (AMPA) in natural waters, batch laboratory and lysimeter transport studies were performed to assess the potential for leaching of the compounds in two agricultural soils. Unlabeled and 14C-labeled glyphosate were added at a rate corresponding to 1.54 kg a.i. ha(-1) on undisturbed sand and clay columns. Leachate was sampled weekly during a period of 748 d for analyses of glyphosate, AMPA, total 14C, and particle-bound residues. Topsoil and subsoil samples were used for determination of glyphosate adsorption, glyphosate degradation, and formation of AMPA and its degradation. The influence of adsorption on glyphosate degradation was confirmed, giving very slow degradation rate in the clay soil (half-life 110-151 d). The kinetics of AMPA residues suggest that although AMPA is always more persistent than glyphosate when formed from glyphosate, its degradation rate can be faster than that of glyphosate. The kinetics also suggest that apart from glyphosate being transformed to AMPA, the sarcosine pathway can be just as significant. The long persistence of glyphosate was also confirmed in the lysimeter study, where glyphosate+AMPA residues constituted 59% of the initial amount of glyphosate added to the clay soil 748 d after application. Despite large amounts of precipitation in the autumn and winter after application, however, these residues were mainly located in the topsoil, and only 0.009 and 0.019% of the initial amount of glyphosate added leached during the whole study period in the sand and clay, respectively. No leaching ofAMPA occurred in the sand, whereas 0.03 g ha(-1) leached in the clay soil.
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Affiliation(s)
- Lars Bergström
- Dep. of Soil and Environment, Swedish Univ. of Agricultural Sciences, P.O. Box 7014, SE-75007 Uppsala, Sweden.
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57
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Staley ZR, Rohr JR, Harwood VJ. The effect of agrochemicals on indicator bacteria densities in outdoor mesocosms. Environ Microbiol 2010; 12:3150-8. [DOI: 10.1111/j.1462-2920.2010.02287.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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58
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Durand S, Sancelme M, Besse-Hoggan P, Combourieu B. Biodegradation pathway of mesotrione: complementarities of NMR, LC-NMR and LC-MS for qualitative and quantitative metabolic profiling. CHEMOSPHERE 2010; 81:372-380. [PMID: 20692682 DOI: 10.1016/j.chemosphere.2010.07.017] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2010] [Revised: 07/04/2010] [Accepted: 07/09/2010] [Indexed: 05/29/2023]
Abstract
Enhanced knowledge of pesticide transformation products formed in the environment could lead to both accurate estimates of the overall effects of these compounds on environmental ecosystems and human health and improved removal processes. These compounds can present chemical and environmental behaviours completely different from the starting active ingredient. The difficulty lies on their identification or/and their quantification due to the lack of analytical reference standards. In this context, ex situ Nuclear Magnetic Resonance (NMR) and Liquid Chromatography-NMR (LC-NMR) were used as complementary tools to LC-Mass Spectrometry (MS) to define the metabolic pathway of mesotrione, an emergent herbicide, by the bacterial strain Bacillus sp. 3B6. The complementarities of ex situ and LC-NMR allowed us to unambiguously identify six metabolites whereas the structures of only four metabolites were suggested by LC-MS. The presence of a new metabolic pathway was evidenced by NMR. These results demonstrate that NMR and LC-NMR spectroscopy provided unambiguous structural information for xenobiotic metabolic profiling, even at moderate magnetic field and allowed direct absolute quantification despite the lack of commercial or synthetic standards, required for LC-MS techniques.
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Affiliation(s)
- Stéphanie Durand
- Clermont Université, Université Blaise Pascal, Laboratoire de Synthèse et Etude de Systèmes à Intérêt Biologique, 63000 Clermont-Ferrand, France
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59
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Potential for bioremediation of agro-industrial effluents with high loads of pesticides by selected fungi. Biodegradation 2010; 22:215-28. [DOI: 10.1007/s10532-010-9389-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2010] [Accepted: 07/06/2010] [Indexed: 10/19/2022]
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60
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Mattozzi MDLP, Keasling JD. Rationally engineered biotransformation of p-nitrophenol. Biotechnol Prog 2010; 26:616-21. [DOI: 10.1002/btpr.382] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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61
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Bazot S, Lebeau T. Effect of immobilization of a bacterial consortium on diuron dissipation and community dynamics. BIORESOURCE TECHNOLOGY 2009; 100:4257-4261. [PMID: 19386487 DOI: 10.1016/j.biortech.2009.03.067] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2008] [Revised: 03/23/2009] [Accepted: 03/24/2009] [Indexed: 05/27/2023]
Abstract
This work intended to study the relationship between diuron herbicide dissipation and the population dynamics of co-cultivated Delftia acidovorans WDL34 (WDL34) and Arthrobacter sp. N4 (N4) for different cell formulations: free cells or immobilization in Ca-alginate beads of one or both strains. GFP-tagged WDL34 and N4 Gram staining allowed analyzing the cell growth and distribution of each strain in both beads and culture medium in the course of the time. Compared to the free cell co-culture of WDL34 and N4, immobilization of WDL34 in Ca-alginate beads co-cultivated with free N4 increased the dissipation rate of diuron by 53% (0.141 mg ml(-1) h(-1)). In that case, immobilization strongly modified the final equilibrium among both strains (highest total N4 to WDL34 ratio). Our results demonstrated that the inoculant formulation played a major role in the cell growth of each cultivated strain possibly increasing diuron dissipation. This optimized cell formulation may allow improving water and soil treatment.
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Affiliation(s)
- Stéphane Bazot
- Laboratoire Ecologie, Systématique et Evolution, UMR8079, UPS-CNRS-ENGREF, Département Ecophysiologie Végétale, Université Paris-sud XI, 91405 Orsay Cedex, France
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62
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Lushchak OV, Kubrak OI, Storey JM, Storey KB, Lushchak VI. Low toxic herbicide Roundup induces mild oxidative stress in goldfish tissues. CHEMOSPHERE 2009; 76:932-7. [PMID: 19450865 DOI: 10.1016/j.chemosphere.2009.04.045] [Citation(s) in RCA: 139] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2009] [Revised: 04/16/2009] [Accepted: 04/19/2009] [Indexed: 05/27/2023]
Abstract
The formulation of Roundup consists of the herbicide glyphosate as the active ingredient with polyethoxylene amine added as a surfactant. The acute toxicity of Roundup (particularly of glyphosate) to animals is considered to be low according to the World Health Organization, but the extensive use of Roundup may still cause environmental problems with negative impact on wildlife, particularly in an aquatic environment where chemicals may persist for a long time. Therefore, we studied the effects of Roundup on markers of oxidative stress and antioxidant defense in goldfish, Carassius auratus. The fish were given 96 h exposure to Roundup at concentrations of 2.5-20 mg L(-1). Exposure to Roundup did not affect levels of lipid peroxides (LOOH) in goldfish brain or liver, and in kidney only the 10 mg L(-1) treatment elevated LOOH by 3.2-fold. Herbicide exposure also had no effect on the concentrations of protein thiols or low molecular mass thiols in kidney, but selective suppression of low molecular mass thiols by 26-29% occurred at some treatment levels in brain and liver. Roundup exposure generally suppressed the activities of superoxide dismutase (SOD), glutathione S-transferase (GST), glutathione reductase and glucose-6-phosphate dehydrogenase in fish tissues. For example, SOD activities were reduced by 51-68% in brain, 58-67% in liver and 33-53% in kidney of Roundup treated fish. GST activity decreased by 29-34% in liver. However, catalase activity increased in both liver and kidney of herbicide-exposed fish. To our knowledge this is the first study to demonstrate a systematic response by the antioxidant systems of fish to Roundup exposure.
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Affiliation(s)
- Oleh V Lushchak
- Department of Biochemistry, Precarpathian National University named after Vassyl Stefanyk, 57 Shevchenko Str., Ivano-Frankivsk 76025, Ukraine
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63
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Cycoń M, Wójcik M, Piotrowska-Seget Z. Biodegradation of the organophosphorus insecticide diazinon by Serratia sp. and Pseudomonas sp. and their use in bioremediation of contaminated soil. CHEMOSPHERE 2009; 76:494-501. [PMID: 19356785 DOI: 10.1016/j.chemosphere.2009.03.023] [Citation(s) in RCA: 140] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Revised: 03/10/2009] [Accepted: 03/11/2009] [Indexed: 05/25/2023]
Abstract
An enrichment culture technique was used for the isolation of bacteria responsible for biodegradation of diazinon in soil. Three bacterial strains were screened and identified by MIDI-FAME profiling as Serratia liquefaciens, Serratia marcescens and Pseudomonas sp. All isolates were able to grow in mineral salt medium (MSM) supplemented with diazinon (50 mgL(-1)) as a sole carbon source, and within 14d 80-92% of the initial dose of insecticide was degraded by the isolates and their consortium. Degradation of diazinon was accelerated when MSM was supplemented with glucose. However, this process was linked with the decrease of pH values, after glucose utilization. Studies on biodegradation in sterilized soil showed that isolates and their consortium exhibited efficient degradation of insecticide (100mg kg(-1) soil) with a rate constant of 0.032-0.085d(-1), and DT(50) for diazinon was ranged from 11.5d to 24.5d. In contrast, degradation of insecticide in non-sterilized soil, non-supplemented earlier with diazinon, was characterized by a rate constant of 0.014d(-1) and the 7-d lag phase, during which only 2% of applied dose was degraded. The results suggested a strong correlation between microbial activity and chemical processes during diazinon degradation. Moreover, isolated bacterial strains may have potential for use in bioremediation of diazinon-contaminated soils.
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Affiliation(s)
- Mariusz Cycoń
- Department of Microbiology, Faculty of Pharmacy, Medical University of Silesia, Jagiellońska 4, 41-200 Sosnowiec, Poland.
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64
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Yair S, Ofer B, Arik E, Shai S, Yossi R, Tzvika D, Amir K. Organophosphate Degrading Microorganisms and Enzymes as Biocatalysts in Environmental and Personal Decontamination Applications. Crit Rev Biotechnol 2008; 28:265-75. [DOI: 10.1080/07388550802455742] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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65
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Nolan BT, Dubus IG, Surdyk N, Fowler HJ, Burton A, Hollis JM, Reichenberger S, Jarvis NJ. Identification of key climatic factors regulating the transport of pesticides in leaching and to tile drains. PEST MANAGEMENT SCIENCE 2008; 64:933-944. [PMID: 18416432 DOI: 10.1002/ps.1587] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
BACKGROUND Key climatic factors influencing the transport of pesticides to drains and to depth were identified. Climatic characteristics such as the timing of rainfall in relation to pesticide application may be more critical than average annual temperature and rainfall. The fate of three pesticides was simulated in nine contrasting soil types for two seasons, five application dates and six synthetic weather data series using the MACRO model, and predicted cumulative pesticide loads were analysed using statistical methods. RESULTS Classification trees and Pearson correlations indicated that simulated losses in excess of 75th percentile values (0.046 mg m(-2) for leaching, 0.042 mg m(-2) for drainage) generally occurred with large rainfall events following autumn application on clay soils, for both leaching and drainage scenarios. The amount and timing of winter rainfall were important factors, whatever the application period, and these interacted strongly with soil texture and pesticide mobility and persistence. Winter rainfall primarily influenced losses of less mobile and more persistent compounds, while short-term rainfall and temperature controlled leaching of the more mobile pesticides. CONCLUSIONS Numerous climatic characteristics influenced pesticide loss, including the amount of precipitation as well as the timing of rainfall and extreme events in relation to application date. Information regarding the relative influence of the climatic characteristics evaluated here can support the development of a climatic zonation for European-scale risk assessment for pesticide fate.
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Affiliation(s)
- Bernard T Nolan
- BRGM, Water Division, Avenue C Guillemin, BP 36009, 45060 Orléans Cedex 2, France
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66
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Forlani G, Pavan M, Gramek M, Kafarski P, Lipok J. Biochemical bases for a widespread tolerance of cyanobacteria to the phosphonate herbicide glyphosate. PLANT & CELL PHYSIOLOGY 2008; 49:443-56. [PMID: 18263622 DOI: 10.1093/pcp/pcn021] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Possible non-target effects of the widely used, non-selective herbicide glyphosate were examined in six cyanobacterial strains, and the basis of their resistance was investigated. All cyanobacteria showed a remarkable tolerance to the herbicide up to millimolar levels. Two of them were found to possess an insensitive form of glyphosate target, the shikimate pathway enzyme 5-enol-pyruvyl-shikimate-3-phosphate synthase. Four strains were able to use the phosphonate as the only phosphorus source. Low uptake rates were measured only under phosphorus deprivation. Experimental evidence for glyphosate metabolism was also obtained in strains apparently unable to use the phosphonate. Results suggest that various mechanisms may concur in providing cyanobacterial strains with herbicide tolerance. The data also account for their widespread ability to metabolize the phosphonate. However, such a capability seems limited by low cell permeability to glyphosate, and is rapidly repressed when inorganic phosphate is available.
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Affiliation(s)
- Giuseppe Forlani
- Department of Biology and Evolution, University of Ferrara, Italy.
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67
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Wang X, Wu N, Guo J, Chu X, Tian J, Yao B, Fan Y. Phytodegradation of organophosphorus compounds by transgenic plants expressing a bacterial organophosphorus hydrolase. Biochem Biophys Res Commun 2008; 365:453-8. [PMID: 17996731 DOI: 10.1016/j.bbrc.2007.10.193] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2007] [Accepted: 10/30/2007] [Indexed: 11/18/2022]
Abstract
Organophosphorus (OP) compounds are widely used as pesticides in agriculture but cause broad-area environmental pollution. In this work, we have expressed a bacterial organophosphorus hydrolase (OPH) gene in tobacco plants. An assay of enzyme activity showed that transgenic plants could secrete OPH into the growth medium. The transgenic plants were resistant to methyl parathion (Mep), an OP pesticide, as evidenced by a toxicity test showing that the transgenic plants produced greater shoot and root biomass than did the wild-type plants. Furthermore, at 0.02% (v/v) Mep, the transgenic plants degraded more than 99% of Mep after 14 days of growth. Our work indicates that transgenic plants expressing an OPH gene may provide a new strategy for decontaminating OP pollutants.
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Affiliation(s)
- Xiaoxue Wang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
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68
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Wheelock CE, Phillips BM, Anderson BS, Miller JL, Miller MJ, Hammock BD. Applications of carboxylesterase activity in environmental monitoring and toxicity identification evaluations (TIEs). REVIEWS OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2008; 195:117-178. [PMID: 18418956 DOI: 10.1007/978-0-387-77030-7_5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
This review has examined a number of issues surrounding the use of carboxylesterase activity in environmental monitoring. It is clear that carboxylesterases are important enzymes that deserve increased study. This class of enzymes appears to have promise for employment in environmental monitoring with a number of organisms and testing scenarios, and it is appropriate for inclusion in standard monitoring assays. Given the ease of most activity assays, it is logical to report carboxylesterase activity levels as well as other esterases (e.g., acetylcholinesterase). Although it is still unclear as to whether acetylcholinesterase or carboxylesterase is the most "appropriate" biomarker, there are sufficient data to suggest that at the very least further studies should be performed with carboxylesterases. Most likely, data will show that it is optimal to measure activity for both enzymes whenever possible. Acetylcholinesterase has the distinct advantage of a clear biological function, whereas the endogenous role of carboxylesterases is still unclear. However, a combination of activity measurements for the two enzyme systems will provide a much more detailed picture of organism health and insecticide exposure. The main outstanding issues are the choice of substrate for activity assays and which tissues/organisms are most appropriate for monitoring studies. Substrate choice is very important, because carboxylesterase activity consists of multiple isozymes that most likely fluctuate on an organism- and tissue-specific basis. It is therefore difficult to compare work in one organism with a specific substrate with work performed in a different organism with a different substrate. An attempt should therefore be made to standardize the method. The most logical choice is PNPA (p-nitrophenyl acetate), as this substrate is commercially available, requires inexpensive optics for assay measurements, and has been used extensively in the literature. However, none of these beneficial properties indicates that the substrate is an appropriate surrogate for a specific compound, e.g., pyrethroid-hydrolyzing activity. It will most likely be necessary to have more specific surrogate substrates for use in assays that require information on the ability to detoxify/hydrolyze specific environmental contaminants. The use of carboxylesterase activity in TIE protocols appears to have excellent promise, but there are further technical issues that should be addressed to increase the utility of the method. The main concerns include the large amount of nonspecific protein added to the testing system, which can lead to undesirable side effects including nonspecific reductions in observed toxicity, decrease in dissolved oxygen content, and organism growth. It is probable that these issues can be resolved with further assay development. The ideal solution would be to have a commercial recombinant carboxylesterase that possessed elevated pyrethroid-hydrolysis activity and which was readily available, homogeneous, and inexpensive. The availability of such an enzyme would address nearly all the current method shortcomings. Such a preparation would be extremely useful for the aquatic toxicology community. Further work should focus on screening available esterases for stability, cost, and activity on pyrethroids, with specific focus on esterases capable of distinguishing type I from type II pyrethroids. It would also be beneficial to identify esterases that are not sensitive to OP insecticides. Many esterases and lipases are available as sets to test chemical reactions for green chemistry, enabling large-scale screening. Other potential approaches to increase the utility of the enzyme include derivatization with polyethylene glycol (PEG) or cyanuric acid chloride to increase stability and reduce microbial degradation. It is also possible that the enzyme could be formulated in a sol gel preparation to increase stability. It is likely that the use of carboxylesterase addition will increase for applications in sediment TIEs. Carboxylesterases are an interesting and useful enzyme family that deserves further study for applications in environmental monitoring as well as to increase our understanding of the fundamental biological role(s) of these enzymes. There are, of course, other enzymes that show high esterase activity on pyrethroids but are not technically carboxylesterases in the alpha/beta-hydrolase fold protein family. These enzymes should also be examined for use in TIE protocols and "esterase" arrays as well as for general applications in environmental monitoring. One can envision the creation of a standardized screen of enzymes with esterase activity to (1) identify environmental contaminants, (2) estimate the potential toxic effects of new compounds on a range of organisms, and (3) monitor organism exposure to agrochemicals (and potentially other contaminants). This approach would provide a multibiomarker integrative assessment of esterase-inhibiting potential of a compound or mixture. In conclusion, much is still unknown about this enzyme family, indicating that this area is still wide open to researchers interested in the applications of carboxylesterase activity as well as basic biological questions into the nature of enzyme activity and the endogenous role of the enzyme.
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Affiliation(s)
- Craig E Wheelock
- Division of Physiological Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Scheeles vãg 2, SE-171 77 Stockholm, Sweden
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69
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Karpouzas DG, Pantelelis I, Menkissoglu-Spiroudi U, Golia E, Tsiropoulos NG. Leaching of the organophosphorus nematicide fosthiazate. CHEMOSPHERE 2007; 68:1359-64. [PMID: 17316750 DOI: 10.1016/j.chemosphere.2007.01.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2006] [Revised: 01/09/2007] [Accepted: 01/10/2007] [Indexed: 05/14/2023]
Abstract
Fosthiazate is an organophosphorus nematicide which was recently included in Annex I of the Directive 91/414/EEC under the clause that it should be used with special care in soils vulnerable to leaching. Thus, the leaching of fosthiazate was investigated in columns packed with three different soils which represented situations of high (site 2), intermediate (site 1) and low (site 3) leaching potential. The recommended dose of fosthiazate was applied at the surface of the soil columns and fosthiazate fate and transport was investigated for the next two months. Fosthiazate concentrations in the leachate collected from the bottom of the columns packed with soil from site 2 exceeded 0.1 microgl(-1) in most cases. This soil was characterized as acidic, indicating longer fosthiazate persistence, with low organic matter content, indicating weak adsorption, thus representing a situation vulnerable to leaching. In contrast, the lowest concentrations of fosthiazate in the leachate were evident in the columns packed with soil from site 3. This soil was characterized as alkaline, indicating faster degradation, with higher organic matter content, indicating stronger adsorption, thus representing a situation not favoring leaching of fosthiazate. The highest concentration of fosthiazate in the leachate from the columns packed with soil from site 2 was 3.44 microgl(-1) compared to 1.17 and 0.16 microgl(-1), which were the corresponding maximum values measured in columns packed with soil from sites 1 and 3, respectively. The results of the current study further suggest that fosthiazate is mobile in soil and can leach under conducive soil conditions like acidic soils with low organic matter content.
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Affiliation(s)
- Dimitrios G Karpouzas
- Department of Biochemistry-Biotechnology, University of Thessaly, Ploutonos 26 & Aiolou Str., Larisa 41221, Greece.
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