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Stress Biology Feb 2024Organophosphate compounds are widely used in agricultural activities to optimize food production. Contamination of field soil by these compounds may result in...
Organophosphate compounds are widely used in agricultural activities to optimize food production. Contamination of field soil by these compounds may result in detrimental effects on soil biota. The aim of the present study was to isolate microorganisms from field soils and evaluate the strains on ability to degrade organophosphates as single isolate and as a consortium. Isolated strains were identified using both biochemical and molecular techniques. Results revealed that, out of the 46 isolated strains, three isolates herein referred to as S6, S36 and S37 showed an average diazinon degradation rate of 76.4%, 76.7% and 76.8% respectively, of the initial dose (50 ppm) within 11 days of incubation in mineral medium. Notably, isolates S36 and S37 were more effective than S6 in degrading diazinon by 40% in soil aliquot after 11 days and therefore were evaluated on biochemical reactions and molecular identification. The isolates showed variable biochemical characteristics. However, both isolates possessed catalase enzyme, but lacked oxidase enzyme. Molecular characterization showed that, the closest species for S36 and S37 were Priestia megaterium and P. arybattia, respectively, based on 16S rRNA gene similarity (> 99%). Combination of the strains increased diazinon degradation ability by 45% compared to single strain treatment. Chlorpyrifos was the most highly degraded organophosphate, compared to phorate and cadusafos. Therefore it is expected that the pesticide-degrading bacteria could be a solution to soil health improvement and contribution to the production of safe agricultural products.
PubMed: 38319394
DOI: 10.1007/s44154-023-00138-6 -
International Journal of Toxicology Jun 2024Organophosphate pesticides are widely used; however, their use is limited due to neurotoxicity and, to a lesser extent, cardiotoxicity in humans. Given the high energy...
Organophosphate pesticides are widely used; however, their use is limited due to neurotoxicity and, to a lesser extent, cardiotoxicity in humans. Given the high energy demands of cardiac muscle, which is characterized by a dense population of mitochondria, any damage to these organelles can exacerbate cardiotoxicity. This study aims to elucidate whether the cardiotoxic effects of organophosphate pesticides originate from mitochondrial dysfunction. To investigate this, toxicogenomic analyses were performed using various tools, such as the Comparative Toxicogenomic Database, GeneMANIA, STRING, and Cytoscape. Results revealed that 11 out of the 13 WHO-recommended Class Ia organophosphate pesticides target genes associated with cardiotoxicity. Notably, three of these genes were mitochondrial, with catalase (CAT) being the common differentially expressed gene among parathion, methyl parathion, and phorate. Furthermore, protein-protein interaction analysis indicated a strong association between CAT and superoxide dismutase 2, mitochondrial (SOD2). Subsequently, isolated heart mitochondria were utilized to assess CAT and superoxide dismutase (SOD) activities . The findings demonstrated that at a concentration of 7.5 ng/µL, both methyl parathion and phorate significantly decreased CAT activity by approximately 35%. Moreover, phorate reduced total SOD and SOD2 activities by 17% and 19%, respectively, at the same concentration. In contrast, none of the three organophosphate pesticides induced the opening of the mitochondrial permeability transition pore. These results suggest that the reduction in CAT and SOD2 activities, critical antioxidant enzymes, leads to the accumulation of reactive oxygen species within mitochondria, ultimately resulting in mitochondrial damage. This mechanism likely underlies the observed cardiotoxicity induced by these organophosphate pesticides.
PubMed: 38897602
DOI: 10.1177/10915818241261624 -
Chemosphere Dec 2023Soil moisture, organic matter, and soil microbes are the key considering factors that control the persistence, degradation, and transformation of applied pesticides...
Soil moisture, organic matter, and soil microbes are the key considering factors that control the persistence, degradation, and transformation of applied pesticides under varied soil conditions. In this study, underlying influence of these factors was assessed through the fates and metabolic transformation of two non-ionic pesticides (e.g., Phorate and Terbufos) in soils. Concisely, two distinct experiments including a customized batch equilibrium (sorption study), and a lab incubation trial (degradation study) were performed, following the OECD guidelines. As per study findings, biochar (BC) amendment was found to be the most influential factors during sorption study, particularly, 1% BC amendment contributed to achieve the best results. In addition, the non-linearity of sorption isotherm (1/n < 1.0) was revealed through Freundlich isotherm, indicating the strong adsorption of studied pesticides onto the soils. On the other hand, during degradation study, soil moisture initiates the enhanced degradation of parent pesticides and subsequent metabolism. In the presence of 40% water holding capacity (WHC), 1% BC amendment enhances the metabolic transformation, while HO treatment could hinder the process. Additionally, the half-life degradation (t) of phorate and terbufos was controlled by biochar amendment, moisture, and soil sterilization, respectively. Finally, BC can accelerate the metabolic transformation, whereas, phorate underwent a metabolic change into sulfoxide and sulfone while terbufos turned into solely sulfoxide. This pioneering study gathered crucial data for understanding the persistence and metabolic transition of non-ionic pesticides in soils and their patterns of degradation.
Topics: Pesticides; Soil; Phorate; Hydrogen Peroxide; Charcoal; Sulfoxides; Soil Pollutants; Adsorption
PubMed: 37844696
DOI: 10.1016/j.chemosphere.2023.140458 -
Environmental Analysis, Health and... Mar 2024Developing countries like Nigeria are increasingly employing pesticides to boost the productivity of their agriculture and food supply, despite the fact that doing so...
Developing countries like Nigeria are increasingly employing pesticides to boost the productivity of their agriculture and food supply, despite the fact that doing so poses a health risk to the general populace. The purpose of this study was to assess pesticide residue levels in Lagos, Nigeria. A total of 18 samples from three neighbourhood markets were collected, and they were then examined for the presence of organochlorine (Endosulfan I, Pentachlorophenol, Heptachlor epoxide, and Endosulfan II) and organophosphate (Dichlorvos, Dimethoate, Phorate, and methyl parathion) residues. During the pre-treatment, the multi-residue Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS citrate) method with the addition of acetonitrile was used, and then samples were analysed using GC-MS. All of the samples contained dichlorvos, but the orange sample's concentration was below the limit of quantification, making quantification impossible. Dimethoate concentrations were below MRLs except waterleaf sample. With a concentration of 0.043 μg/mL, Waterleaf had the highest quantity of dimethoate in the sample. The findings of this study indicate that in order to safeguard the health of consumers, it is necessary to closely monitor organochlorine and organophosphate use nationwide, along with other related pesticides, and to test for pesticide residues in food products.
PubMed: 38631394
DOI: 10.5620/eaht.2024002 -
Microorganisms Jul 2023Eighteen pesticide-degrading endophytic bacteria were isolated from the roots, stems, and leaves of healthy rice plants and identified through 16S rRNA gene sequencing....
Characterization of Growth-Promoting Activities of Consortia of Chlorpyrifos Mineralizing Endophytic Bacteria Naturally Harboring in Rice Plants-A Potential Bio-Stimulant to Develop a Safe and Sustainable Agriculture.
Eighteen pesticide-degrading endophytic bacteria were isolated from the roots, stems, and leaves of healthy rice plants and identified through 16S rRNA gene sequencing. Furthermore, biochemical properties, including enzyme production, dye degradation, anti-bacterial activities, plant-growth-promoting traits, including N-fixation, P-solubilization, auxin production, and ACC-deaminase activities of these naturally occurring endophytic bacteria along with their four consortia, were characterized. HSTU-ABk39 and sp. HSTU-ABk36 displayed inhibition zones of 41.5 ± 1.5 mm, and 29 ± 09 mm against multidrug-resistant human pathogenic bacteria and , respectively. FT-IR analysis revealed that all eighteen isolates were able to degrade chlorpyrifos Our study confirms that pesticide-degrading endophytic bacteria from rice plants play a key role in enhancing plant growth. Notably, rice plants grown in pots containing reduced urea (30%) mixed with either endophytic bacterial consortium-1, consortium-2, consortium-3, or consortia-4 demonstrated an increase of 17.3%, 38.6%, 18.2%, and 39.1% yields, respectively, compared to the control plants grown in pots containing 100% fertilizer. GC-MS/MS analysis confirmed that consortia treatment caused the degradation of chlorpyrifos into different non-toxic metabolites, including 2-Hydroxy-3,5,6 trichloropyridine, Diethyl methane phosphonate, Phorate sulfoxide, and Carbonochloridic. Thus, these isolates could be deployed as bio-stimulants to improve crop production by creating a sustainable biological system.
PubMed: 37512993
DOI: 10.3390/microorganisms11071821 -
Water Research Jun 2024Constructed wetlands (CWs) are widely used in sewage treatment in rural areas, but there are only a few studies on field-scale CWs in treating wastewater-borne...
Constructed wetlands (CWs) are widely used in sewage treatment in rural areas, but there are only a few studies on field-scale CWs in treating wastewater-borne pesticides. In this study, the treatment and metabolic transformation of 29 pesticides in rural domestic sewage by 10 field-scale horizontal flow CWs (HF-CWs), each with a treatment scale of 36‒5000 m/d and operated for 2‒10 years, in Guangzhou, Southern China was investigated. The risk of pesticides in treated effluent and main factors influencing such risk were evaluated. Results demonstrated that HF-CWs could remove pesticides in sewage and reduce their ecological risk in effluent, but the degree varied among types of pesticides. Herbicides had the highest mean removal rate (67.35 %) followed by insecticides (60.13 %), and the least was fungicides (53.22 %). In terms of single pesticide compounds, the mean removal rate of butachlor was the highest (73.32 %), then acetochlor (69.41 %), atrazine (68.28 %), metolachlor (58.40 %), and oxadixyl (53.28 %). The overall removal rates of targeted pesticides in each HF-CWs ranged from 11 %‒57 %, excluding two HF-CWs showing increases in pesticides in treated effluent. Residues of malathion, phorate, and endosulfan in effluent had high-risks (RQ > 5). The pesticide concentration in effluent was mainly affected by that in influent (P = 0.042), and source control was the key to reducing risk. The main metabolic pathways of pesticide in HF-CWs were oxidation, with hydroxyl group to carbonyl group or to form sulfones, the second pathways by hydrolysis, aerobic condition was conducive to the transformation of pesticides. Sulfones were generally more toxic than the metabolites produced by hydrolytic pathways. The present study provides a reference on pesticides for the purification performance improvement, long-term maintenance, and practical sustainable application of field-scale HF-CWs.
Topics: Wetlands; Pesticides; Wastewater; Water Pollutants, Chemical; Risk Assessment; Waste Disposal, Fluid; China
PubMed: 38593607
DOI: 10.1016/j.watres.2024.121568