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BioMed Research International 2014A bacterial strain C5 that can produce new type of marine esterase was isolated and screened from marine sludge. According to 16S rRNA sequence analysis and...
A bacterial strain C5 that can produce new type of marine esterase was isolated and screened from marine sludge. According to 16S rRNA sequence analysis and physiological and biochemical experiments, the strain was identified as Bacillus subtilis. A single isozyme with a molecular weight of 86 kDa was observed by SDS-PAGE and native-PAGE. On this basis, the mechanism of esterase B1 secreted by strain C5 degrading parathion-methyl was explored, and the effects of temperature and pH on the degradation rate were investigated. From the results, p-nitrophenol was one of the degradation products of B1 degrading parathion-methyl, and the best degradation effect could be achieved at the temperature of 40°C and the neutral pH value.
Topics: Aquatic Organisms; Bacillus subtilis; Enzyme Stability; Hydrogen-Ion Concentration; Methyl Parathion; Phylogeny; Proteolysis; RNA, Ribosomal, 16S; Serine Endopeptidases; Temperature
PubMed: 25580438
DOI: 10.1155/2014/863094 -
BMC Public Health Jun 2021Nepal recorded 5754 suicides in 2018-19 - a high number for a relatively small country. Over 24% of these suicides were by poisoning, most by ingestion of highly...
BACKGROUND
Nepal recorded 5754 suicides in 2018-19 - a high number for a relatively small country. Over 24% of these suicides were by poisoning, most by ingestion of highly concentrated agricultural pesticides. Nepal has actively regulated pesticides to reduce their health impacts since 2001. We aimed to analyse Nepal's history of pesticide regulation, pesticides responsible for poisonings, and relate them to national suicide rates.
METHODS
Information on pesticide regulation was collected from the Plant Quarantine and Pesticide Management Centre of the Ministry of Agriculture and Livestock Development. National data on suicides from 1980 to 2019 were obtained from the National Statistical Bureau and Nepal Police. Data on the pesticides responsible for self-poisoning and pesticide suicides over time were obtained from a systematic literature review.
RESULTS
As of June 2020, 171 pesticides were registered for use in Nepal, of which one was extremely hazardous (WHO Class Ia), one other highly hazardous (WHO Class Ib), and 71 moderately hazardous (WHO Class II). Twenty-four pesticides have been banned since 2001, with eight (including five WHO Class I compounds) banned in 2019. Although the suicide rate has increased more than twelve-fold since 1980, particularly for hanging (15-fold increase from 1980 to 2018), fatal pesticide self-poisoning has increased by 13-fold. Methyl-parathion is reported to be the key pesticide responsible for pesticide self-poisoning in Nepal, despite being banned in 2006.
CONCLUSION
The full effect of the recent pesticide policy reform in Nepal remains to be seen. Our analysis shows a continuing increase in suicide numbers, despite bans of the most important pesticide in 2006. This may indicate smuggling across the border and the use of the brand name (Metacid) for pesticides in general making it difficult to identify the responsible pesticide. More information is required from forensic toxicology labs that identify the individual compounds found. The effect of recent bans of common suicide pesticides needs to be monitored over the coming years. Evidence from other Asian countries suggests that HHPs bans will lead to a marked reduction in suicides, as well as fewer cases of occupational poisoning.
Topics: Asia; Eating; Humans; Nepal; Pesticides; Poisoning; Suicide
PubMed: 34120596
DOI: 10.1186/s12889-021-11155-3 -
Global Challenges (Hoboken, NJ) Sep 2022Glyphosate is a globally applied herbicide yet it has been relatively undetectable in-field samples outside of gold-standard techniques. Its presumed nontoxicity toward...
Glyphosate is a globally applied herbicide yet it has been relatively undetectable in-field samples outside of gold-standard techniques. Its presumed nontoxicity toward humans has been contested by the International Agency for Research on Cancer, while it has been detected in farmers' urine, surface waters and crop residues. Rapid, on-site detection of glyphosate is hindered by lack of field-deployable and easy-to-use sensors that circumvent sample transportation to limited laboratories that possess the equipment needed for detection. Herein, the flavoenzyme, glycine oxidase, immobilized on platinum-decorated laser-induced graphene (LIG) is used for selective detection of glyphosate as it is a substrate for GlyOx. The LIG platform provides a scaffold for enzyme attachment while maintaining the electronic and surface properties of graphene. The sensor exhibits a linear range of 10-260 m, detection limit of 3.03 m, and sensitivity of 0.991 nA m . The sensor shows minimal interference from the commonly used herbicides and insecticides: atrazine, 2,4-dichlorophenoxyacetic acid, dicamba, parathion-methyl, paraoxon-methyl, malathion, chlorpyrifos, thiamethoxam, clothianidin, and imidacloprid. Sensor function is further tested in complex river water and crop residue fluids, which validate this platform as a scalable, direct-write, and selective method of glyphosate detection for herbicide mapping and food analysis.
PubMed: 36176938
DOI: 10.1002/gch2.202200057 -
Nanomaterials (Basel, Switzerland) Apr 2022Flexible sensors are highly advantageous for integration in portable and wearable devices. In this work, we propose and validate a simple strategy to achieve whole...
Flexible sensors are highly advantageous for integration in portable and wearable devices. In this work, we propose and validate a simple strategy to achieve whole wafer-size flexible SERS substrate via a one-step metal-assisted chemical etching (MACE). A pre-patterning Si wafer allows for PSi structures to form in tens of microns areas, and thus enables easy detachment of PSi film pieces from bulk Si substrates. The morphology, porosity, and pore size of PS films can be precisely controlled by varying the etchant concentration, which shows obvious effects on film integrity and wettability. The cracks and self-peeling of Psi films can be achieved by the drying conditions after MACE, enabling transfer of Psi films from Si wafer to any substrates, while maintaining their original properties and vertical alignment. After coating with a thin layer of silver (Ag), the rigid and flexible PSi films before and after transfer both show obvious surface-enhanced Raman scattering (SERS) effect. Moreover, flexible PSi films SERS substrates have been demonstrated with high sensitivity (down to 2.6 × 10 g/cm) for detection of methyl parathion (MPT) residues on a curved apple surface. Such a method provides us with quick and high throughput fabrication of nanostructured materials for sensing, catalysis, and electro-optical applications.
PubMed: 35407309
DOI: 10.3390/nano12071191 -
Water Research Dec 2008The photodegradation of parathion in aqueous solutions by UV and UV/H(2)O(2) processes was evaluated. Direct photolysis of parathion both by LP (low pressure) and MP...
The photodegradation of parathion in aqueous solutions by UV and UV/H(2)O(2) processes was evaluated. Direct photolysis of parathion both by LP (low pressure) and MP (medium pressure) lamps at pH 7 was very slow with quantum yields of 6.67+/-0.33x10(-4) and 6.00+/-1.06x10(-4)molE(-1), respectively. Hydrogen peroxide enhanced the photodegradation of parathion through the reaction between UV generated hydroxyl radical and parathion with a second-order reaction rate constant of 9.70+/-0.45x10(9)M(-1)s(-1). An optimum molar ratio between hydrogen peroxide and parathion was determined to be between 300 and 400. Photodegradation of parathion yielded several organic byproducts, of which the paraoxon, 4-nitrophenol, O,O,O-triethyl thiophosphate and O,O-diethyl-methyl thiophosphate were quantified and their occurrence during UV/H(2)O(2) processes were discussed. NO(2)(-), PO(4)(3-), NO(3)(-) and SO(4)(2-) were the major anionic byproducts of parathion photodegradation and their recover ratios were also discussed. A photodegradation scheme suggesting three simultaneous pathways was proposed in the study.
Topics: Hydrogen Peroxide; Insecticides; Oxidation-Reduction; Parathion; Solutions; Ultraviolet Rays; Water
PubMed: 18834610
DOI: 10.1016/j.watres.2008.08.023 -
International Journal of Environmental... Aug 2022Pesticide-related mental health issues in Thailand, an upper-middle-income country, are not well known. This study aimed to investigate the association between the...
Pesticide-related mental health issues in Thailand, an upper-middle-income country, are not well known. This study aimed to investigate the association between the history of occupational exposure to pesticides and the mental health of Thai farmers. A cross-sectional study was carried out in the areas around Chiang Mai, a large city in Northern Thailand, between June 2020 and January 2021. A total of 6974 farmers from six districts were interviewed to determine whether they regularly experienced symptoms related to mental health by the Self-Reporting Questionnaire (SRQ-20) as well as their lifetime history of agricultural pesticide exposure from 31 active ingredients and five functional categories: insecticides, herbicides, fungicides, rodenticides, and molluscicides. The cut-off of 6 was used to evaluate probable mental disorder. Most of the farmers under investigation were men (53.8%), with a mean age of 55.2 (11.7) years, and were involved mainly in the planting of rice, fruit, and vegetables. About 86.7% reported having used pesticides on their crops at some point in their lives-mostly glyphosate, paraquat, 2,4-D, methomyl, and carbofuran. All functional groups, as well as pesticide classes like organochlorines, organophosphates, and carbamates, were significantly associated with a higher risk of probable mental disorder based on exposure duration, frequency, personal protective equipment usage, and hygienic behavior. In a model with multiple pesticides, there was an association between mental disorder and exposure to endosulfan (AOR = 2.27, 95%CI = 1.26-4.08) and methyl parathion (AOR = 2.26, 95%CI = 1.26-4.06). Having previously reported pesticide poisoning symptoms was related to mental disorder (AOR = 7.97, 95%CI = 5.16-12.31), the findings provided evidence of pesticide exposure posing a risk to farmers' mental health, particularly long-term and high-intensity exposure.
Topics: Agriculture; Cross-Sectional Studies; Farmers; Female; Health Status; Humans; Male; Middle Aged; Occupational Exposure; Pesticides; Thailand
PubMed: 35955007
DOI: 10.3390/ijerph19159654 -
New Biotechnology Dec 2022In Escherichia coli, acyl carrier protein (ACP) is posttranslationally converted into its active holo-ACP form via covalent linkage of 4'-phosphopantetheine (4'-PP) to...
In Escherichia coli, acyl carrier protein (ACP) is posttranslationally converted into its active holo-ACP form via covalent linkage of 4'-phosphopantetheine (4'-PP) to residue serine-36. We found that the long flexible 4'-PP arm could react chemoselectively with the iodoacetyl group introduced on solid supports with high efficiency under mild conditions. Based on this finding, we developed site-selective immobilisation of proteins via the active holo-ACP fusion tag, independently of the physicochemical properties of the protein of interest. Furthermore, the molecular ratios of co-immobilised proteins can be manipulated because the tethering process is predominantly directed by the molar concentrations of diverse holo-ACP fusions during co-immobilisation. Conveniently tuning the molecular ratios of co-immobilised proteins allows their cooperation, leading to a highly productive multi-protein co-immobilisation system. Kinetic studies of enzymes demonstrated that α-amylase (Amy) and methyl parathion hydrolase (MPH) immobilised via active tag holo-ACP had higher catalytic efficiency (k/Km) in comparison with their corresponding counterparts immobilised via the sulfhydryl groups (-SH) of these proteins. The immobilised holo-ACP-Amy also presented higher thermostability compared with free Amy. The enhanced α-amylase thermostability upon immobilisation via holo-ACP renders it more suitable for industrial application.
Topics: Kinetics; Pantetheine; Acyl Carrier Protein; Escherichia coli; alpha-Amylases; Immobilized Proteins
PubMed: 36307012
DOI: 10.1016/j.nbt.2022.10.004 -
Environment International Dec 2019Pesticide exposure during pregnancy is thought to adversely affect fetal growth, which in turn may impact child growth, but results have been inconsistent across studies...
BACKGROUND
Pesticide exposure during pregnancy is thought to adversely affect fetal growth, which in turn may impact child growth, but results have been inconsistent across studies and few have explored these effects in developing countries.
OBJECTIVES
To quantify urinary concentrations of pesticide biomarkers in early pregnancy (<16 weeks' gestation), and to estimate the association of these concentrations with preterm birth, low birth weight, small for gestational age, and stunting at ~1 and 2 years of age.
METHODS
Eight pesticide biomarkers were quantified in urine collected from 289 pregnant women (aged 18-40 years) participating in a birth cohort study in Bangladesh. Anthropometry measurements were conducted on the index child at birth and approximately 1 and 2 years of age. A directed acyclic graph was used to identify minimal sufficient adjustment sets. Log-binomial regression was used to estimate the relative risk (RR) with 95% confidence intervals (CI).
RESULTS
3,5,6-trichloro-2-pyridinol (TCPY), a metabolite of chlorpyrifos and chlorpyrifos methyl, and 4-nitrophenol, a metabolite of parathion and methyl parathion, were detected in nearly all women with geometric mean (95% CI) values of 3.17 (2.82-3.56) and 18.66 (17.03-20.46) µg/g creatinine, respectively. 3-phenoxybenzoic acid (3-PBA), a non-specific metabolite of several pyrethroids, and 2-isopropyl-4-methyl-6-hydroxypyrimidine (IMPY), a diazinon metabolite, were detected in 19.8% and 16.1% of women, respectively. The remaining four pesticide biomarkers were detected in <10% of women. Women in the highest quartile of 4-nitrophenol were more than 3 times more likely to deliver preterm than women in the lowest quartile: unadjusted RR (95% CI), 3.57 (1.65, 7.73). Women in the highest quartile of 4-nitrophenol were also at increased risk of having a child born small for gestational age: RR (95% CI) adjusted for household income, maternal education, and maternal total energy and meat intake, 3.81 (1.10, 13.21). Women with detectable concentrations of IMPY were at increased risk of having a child born with low birth weight compared to women with non-detectable concentrations: adjusted RR (95% CI), 2.13 (1.12, 4.08). We observed no association between any of the pesticide biomarkers and stunting at 1 or 2 years of age.
DISCUSSION
Exposure to the insecticides parathion and diazinon during early pregnancy may increase the risk of adverse birth outcomes.
Topics: Adult; Bangladesh; Child, Preschool; Cohort Studies; Female; Growth Disorders; Humans; Infant; Infant, Low Birth Weight; Infant, Newborn; Maternal Exposure; Pesticides; Pregnancy; Pregnancy Outcome; Premature Birth; Rural Population; Young Adult
PubMed: 31675560
DOI: 10.1016/j.envint.2019.105243 -
Heliyon Sep 2023Organophosphorus Pesticides () are among the extensively used pesticides throughout the world to boost agricultural production. However, persistent residues of these... (Review)
Review
Organophosphorus Pesticides () are among the extensively used pesticides throughout the world to boost agricultural production. However, persistent residues of these toxic pesticides in various vegetables, fruits, and drinking water poses detrimental health effects. Consequently, the rapid monitoring of these harmful chemicals through simple and cost-effective methods has become crucial. In such an instance, electrochemical methods offer simple, rapid, sensitive, reproducible, and affordable detection pathways. To overcome the limitations associated with electrochemical enzymatic sensors, non-enzymatic sensors have emerged as promising and simpler alternatives. The non-enzymatic sensors have demonstrated superior activity, reaching detection limit up to femto (10) molar concentration in recent years, leveraging higher selectivity obtained through the molecularly imprinted polymers, synergistic effects between carbonaceous nanomaterials and metals, metal oxide alloys, and other alternative approaches. Herein, this review paper provides an overview of the recent advancements in the development of non-enzymatic electrochemical sensors for the detection of commonly used OPPs, such as Chlorpyrifos (), Diazinon (), Malathion (), Methyl parathion () and Fenthion (). The design method of the electrodes, electrode functioning mechanism, and their analytical performance metrics, such as limit of detection, sensitivity, selectivity, and linearity range, were reviewed and compared. Furthermore, the existing challenges within this rapidly growing field were discussed along with their potential solutions which will facilitate the fabrication of advanced and sustainable non-enzymatic sensors in the future.
PubMed: 37662791
DOI: 10.1016/j.heliyon.2023.e19299 -
Microbiological Research Aug 2022Microbes are crucial in removing various xenobiotics, including pesticides, from the environment, specifically by mineralizing these hazardous pollutants. However, the...
Microbes are crucial in removing various xenobiotics, including pesticides, from the environment, specifically by mineralizing these hazardous pollutants. However, the specific procedure of microbe-mediated pesticide degradation and its consequence on the environment remain elusive owing to limitations in culturing techniques. Therefore, in this study, we have investigated i) the physicochemical and elemental compositions of PCAS (pesticide-contaminated agricultural soils) and NS (natural soils); ii) the bacterial communities and degradation pathways, as well as some novel biodegradation genes (BDGs) and pesticide degradation genes (PDGs) across two different landscapes (PCAS and NS) by applying high-throughput sequencing. The chemical and elemental composition analyses showed that all nutrients (P, K, N, S, Mn, B, and Zn) were significantly higher in PCAS than in NS (p ≤ 0.05). The results of the 16S rRNA amplicon sequencing analysis of pesticide-contaminated (PCAS-1, PCAS-2, PCAS-3, PCAS-4) samples showed that the relative abundance of the phylum Proteobacteria (30-36%) > Actinobacteria (15-20%) > Firmicutes (13-14%) > Bacteroidetes (7-13%), were higher compared to the natural soil (NS-1, NS2). Consistent with this, a phylogenetic shift was observed with (alpha, beta, and gamma Proteobacteria) being abundant in PCAS, whereas delta and epsilon groups were more prevalent in NS. The functional characterization of the PCAS and NS by PICRUSt2 revealed that bacterial communities play a significant role in pesticide metabolism. Predictive metagenome analysis of contaminated soils showed the role of core degrading genes in membrane transport, stress response, regulatory genes, resource transport, and environmental sensing. Furthermore, 14 BDGs and 30 PDGs were examined, with a relative abundance of 0.081-1.029 % and 0.107-0.8903 % in each PCAS, respectively. The major BDGs and PDGs, with the compounds they hydrolyze, include ppo (polyphenol oxidase and laccase), CYP (cytochrome p450 protein), lip gene (lignin peroxidase), similarly, among the PDGs mhel (carbendazim), opd (organophosphate), mpd (methyl parathion), atzA, atzB, atzD, atzF and trzN (atrazine), chd (chlorothalonil), hdx (metamitron), hdl-1 (isoproturon) and fmo (nicosulfuron). Overall, our findings demonstrated the significance of utilizing metagenomic methods to predict microbial aided degradation in the ecology of contaminated environments.
Topics: Bacteria; Biodegradation, Environmental; Metagenome; Pesticides; Phylogeny; RNA, Ribosomal, 16S; Soil; Soil Microbiology; Soil Pollutants
PubMed: 35660194
DOI: 10.1016/j.micres.2022.127081