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Prashant S. Phale - One of the best experts on this subject based on the ideXlab platform.

  • Metabolic regulation and chromosomal localization of Carbaryl degradation pathway in Pseudomonas sp. strains C4, C5 and C6
    Archives of Microbiology, 2013
    Co-Authors: Randhir Singh, Vikas D. Trivedi, Prashant S. Phale
    Abstract:

    Pseudomonas sp. strains C4, C5 and C6 degrade Carbaryl (1-naphthyl N -methylcarbamate) via 1-naphthol, 1,2-dihydroxynaphthalene, salicylate and gentisate. Carbon source-dependent metabolic studies suggest that enzymes responsible for Carbaryl degradation are probably organized into ‘upper’ (Carbaryl to salicylate), ‘middle’ (salicylate to gentisate) and ‘lower’ (gentisate to TCA cycle) pathway. Carbaryl and 1-naphthol were found to induce all Carbaryl pathway enzymes, while salicylate and gentisate induce middle and lower pathway enzymes. The strains were found to harbor plasmid(s), and Carbaryl degradation property was found to be stable. Genes encoding enzymes of the degradative pathway such as 1-naphthol 2-hydroxylase, salicylaldehyde dehydrogenase, salicylate 5-hydroxylase and gentisate 1,2-dioxygenase were amplified from chromosomal DNA of these strains. The gene-specific PCR products were sequenced from strain C6, and phylogenetic tree was constructed. Southern hybridization and PCR analysis using gel eluted DNA as template supported the presence of pathway genes onto the chromosome and not on the plasmid(s).

  • metabolism of Carbaryl via 1 2 dihydroxynaphthalene by soil isolates pseudomonas sp strains c4 c5 and c6
    Applied and Environmental Microbiology, 2005
    Co-Authors: Vandana P Swetha, Prashant S. Phale
    Abstract:

    Pseudomonas sp. strains C4, C5, and C6 utilize Carbaryl as the sole source of carbon and energy. Identification of 1-naphthol, salicylate, and gentisate in the spent media; whole-cell O2 uptake on 1-naphthol, 1,2-dihydroxynaphthalene, salicylaldehyde, salicylate, and gentisate; and detection of key enzymes, viz, Carbaryl hydrolase, 1-naphthol hydroxylase, 1,2-dihydroxynaphthalene dioxygenase, and gentisate dioxygenase, in the cell extract suggest that Carbaryl is metabolized via 1-naphthol, 1,2-dihydroxynaphthalene, and gentisate. Here, we demonstrate 1-naphthol hydroxylase and 1,2-dihydroxynaphthalene dioxygenase activities in the cell extracts of Carbaryl-grown cells. 1-Naphthol hydroxylase is present in the membrane-free cytosolic fraction, requires NAD(P)H and flavin adenine dinucleotide, and has optimum activity in the pH range 7.5 to 8.0. Carbaryl-degrading enzymes are inducible, and maximum induction was observed with Carbaryl. Based on these results, the proposed metabolic pathway is Carbaryl → 1-naphthol → 1,2-dihydroxynaphthalene → salicylaldehyde → salicylate → gentisate → maleylpyruvate.

Michelle L. Mcwhorter - One of the best experts on this subject based on the ideXlab platform.

  • The effects of Carbaryl on the development of zebrafish (Danio rerio) embryos.
    Zebrafish, 2012
    Co-Authors: Elizabeth N. Schock, Windsor C. Ford, Kirsten J. Midgley, Joseph G. Fader, Michael N. Giavasis, Michelle L. Mcwhorter
    Abstract:

    In the United States, Sevin™ brand insecticide is one of the most commonly used insecticides. The active ingredient in Sevin™, Carbaryl (1-napthyl-N-methylcarbamate), is a known acetylcholinesterase (AChE) inhibitor that prevents the breakdown of acetylcholine to acetate and choline at the synapse. While Carbaryl successfully causes the death of insects by paralysis, it has also been shown to have negative effects on the development of several nontarget species. To study the effects of Carbaryl on nontarget species, zebrafish (Danio rerio) were used, as they are a good model for both toxicology and development studies. Our study suggests that Carbaryl induces changes in morphology, specifically in embryo size and shape. Additionally, Carbaryl causes defects in heart formation that is characterized by a decrease in heart rate and a developmental delay/defect in cardiac looping. A significant decrease in the number of spinal cord neurons present was also observed. Further investigation showed that there was an increase in cell death in Carbaryl-treated embryos. The results indicate that Carbaryl may have a greater environmental impact than initially intended. Our study, which was conducted solely by undergraduates at a liberal arts college, indicates that Carbaryl may be detrimental to the development of nontarget species.

Vandana P Swetha - One of the best experts on this subject based on the ideXlab platform.

  • metabolism of Carbaryl via 1 2 dihydroxynaphthalene by soil isolates pseudomonas sp strains c4 c5 and c6
    Applied and Environmental Microbiology, 2005
    Co-Authors: Vandana P Swetha, Prashant S. Phale
    Abstract:

    Pseudomonas sp. strains C4, C5, and C6 utilize Carbaryl as the sole source of carbon and energy. Identification of 1-naphthol, salicylate, and gentisate in the spent media; whole-cell O2 uptake on 1-naphthol, 1,2-dihydroxynaphthalene, salicylaldehyde, salicylate, and gentisate; and detection of key enzymes, viz, Carbaryl hydrolase, 1-naphthol hydroxylase, 1,2-dihydroxynaphthalene dioxygenase, and gentisate dioxygenase, in the cell extract suggest that Carbaryl is metabolized via 1-naphthol, 1,2-dihydroxynaphthalene, and gentisate. Here, we demonstrate 1-naphthol hydroxylase and 1,2-dihydroxynaphthalene dioxygenase activities in the cell extracts of Carbaryl-grown cells. 1-Naphthol hydroxylase is present in the membrane-free cytosolic fraction, requires NAD(P)H and flavin adenine dinucleotide, and has optimum activity in the pH range 7.5 to 8.0. Carbaryl-degrading enzymes are inducible, and maximum induction was observed with Carbaryl. Based on these results, the proposed metabolic pathway is Carbaryl → 1-naphthol → 1,2-dihydroxynaphthalene → salicylaldehyde → salicylate → gentisate → maleylpyruvate.

Elizabeth N. Schock - One of the best experts on this subject based on the ideXlab platform.

  • The effects of Carbaryl on the development of zebrafish (Danio rerio) embryos.
    Zebrafish, 2012
    Co-Authors: Elizabeth N. Schock, Windsor C. Ford, Kirsten J. Midgley, Joseph G. Fader, Michael N. Giavasis, Michelle L. Mcwhorter
    Abstract:

    In the United States, Sevin™ brand insecticide is one of the most commonly used insecticides. The active ingredient in Sevin™, Carbaryl (1-napthyl-N-methylcarbamate), is a known acetylcholinesterase (AChE) inhibitor that prevents the breakdown of acetylcholine to acetate and choline at the synapse. While Carbaryl successfully causes the death of insects by paralysis, it has also been shown to have negative effects on the development of several nontarget species. To study the effects of Carbaryl on nontarget species, zebrafish (Danio rerio) were used, as they are a good model for both toxicology and development studies. Our study suggests that Carbaryl induces changes in morphology, specifically in embryo size and shape. Additionally, Carbaryl causes defects in heart formation that is characterized by a decrease in heart rate and a developmental delay/defect in cardiac looping. A significant decrease in the number of spinal cord neurons present was also observed. Further investigation showed that there was an increase in cell death in Carbaryl-treated embryos. The results indicate that Carbaryl may have a greater environmental impact than initially intended. Our study, which was conducted solely by undergraduates at a liberal arts college, indicates that Carbaryl may be detrimental to the development of nontarget species.

Shuk Han Cheng - One of the best experts on this subject based on the ideXlab platform.

  • toxicity and cardiac effects of Carbaryl in early developing zebrafish danio rerio embryos
    Toxicology and Applied Pharmacology, 2007
    Co-Authors: Chun Chi Lin, Michelle Nga Yu Hui, Shuk Han Cheng
    Abstract:

    Carbaryl, an acetylcholinesterase inhibitor, is known to be moderately toxic to adult zebrafish and has been reported to cause heart malformations and irregular heartbeat in medaka. We performed experiments to study the toxicity of Carbaryl, specifically its effects on the heart, in early developing zebrafish embryos. LC50 and EC50 values for Carbaryl at 28 h post-fertilization were 44.66 μg/ml and 7.52 μg/ml, respectively, and 10 μg/ml Carbaryl was used in subsequent experiments. After confirming acetylcholinesterase inhibition by Carbaryl using an enzymatic method, we observed red blood cell accumulation, delayed hatching and pericardial edema, but not heart malformation as described in some previous reports. Our chronic exposure data also demonstrated Carbaryl-induced bradycardia, which is a common effect of acetylcholinesterase inhibitors due to the accumulation of acetylcholine, in embryos from 1 day post-fertilization (dpf) to 5 dpf. The distance between the sinus venosus, the point where blood enters the atrium, and the bulbus arteriosus, the point where blood leaves the ventricle, indicated normal looping of the heart tube. Immunostaining of myosin heavy chains with the ventricle-specific antibody MF20 and the atrium-specific antibody S46 showed normal development of heart chambers. At the same time, acute exposure resulted in Carbaryl-induced bradycardia. Heart rate dropped significantly after a 10-min exposure to 100 μg/ml Carbaryl but recovered when Carbaryl was removed. The novel observation of Carbaryl-induced bradycardia in 1- and 2-dpf embryos suggested that Carbaryl affected cardiac function possibly through an alternative mechanism other than acetylcholinesterase inhibition such as inhibition of calcium ion channels, since acetylcholine receptors in zebrafish are not functional until 3 dpf. However, the exact nature of this mechanism is currently unknown, and thus further studies are required.