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Kang, Dong Gyun; Kim, Jaoon Young Hwan; Joon, Hyung

doi:10.1023/a:1015568727825

Cited by 38 publications

(5 citation statements)

References 21 publications

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“…1). Plasmid pTO [20] that carries opd gene for expression of cytosolic OPH, was also used as a negative control. Recombinant strains bearing plasmids were inoculated in M9 medium (12.8 g/L Na 2 HPO 4 ·7H 2 O, 3 g/L KH 2 PO 4 , 0.5 g/L NaCl, 1 g/L NH 4 Cl, 3 mg/L CaCl 2 , 1 mM MgSO 4 ) containing 0.5% (w/v) glucose and 50 µg/mL of ampicillin at the final concentration.…”

Section: Introductionmentioning

confidence: 99%

Efficient cell surface display of organophosphorous hydrolase using N-terminal domain of ice nucleation protein in Escherichia coli

Kang

et al. 2008

Korean J. Chem. Eng.

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Recombinant Escherichia coli systems expressing organophosphorous hydrolase (OPH) have been used for detoxifying toxic organophosphate compounds. However, a whole cell biocatalyst system has an intrinsic problem due to substrate diffusion limitation by its cell membrane. As a strategy for reducing this diffusion barrier limitation to enhance whole cell biocatalytic activity, we engineered E. coli cells to target OPH on cell surface using ice nucleation protein (InaK) as a surface targeting motif, especially N-terminal domain of InaK (InaK-N). The whole cell OPH activities of the cells expressing InaK/OPH fusion constructs were higher (~2.5-fold for InaK-N and ~5.7-fold for combined N-and C-terminal domain of InaK (InaK-NC)) than that of the cells expressing cytosolic OPH. Interestingly, the membrane targeting efficiency of the cells expressing InaK-N/OPH fusion proteins was ~2.2-fold higher compared to the cells expressing InaK-NC/OPH even though both whole cell and total cell lysate OPH activities were lower. Therefore, we found that the small size N-terminal domain of InaK is more efficient for targeting OPH on the cell surface, and the surface display of OPH using N-terminal InaK domain can reduce the mass-transfer problem in whole cell bioconversion system.

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Section: Introductionmentioning

confidence: 99%

Efficient cell surface display of organophosphorous hydrolase using N-terminal domain of ice nucleation protein in Escherichia coli

Kang

et al. 2008

Korean J. Chem. Eng.

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“…Recombinant plasmid pTOH that contains oph gene fused with hexa-histidine affinity tag under T7 promoter was used ( Fig. 2) [18]. Recombinant plasmid bearing strain was cultured in M9 minimal medium (12.8 g/L Na 2 HPO 4 ·7H 2 O, 3 g/L KH 2 PO 4 , 0.5 g/L NaCl, 1 g/L NH 4 Cl, 3 mg/L CaCl 2 , 1 mM MgSO 4 ) containing 0.5% (w/v) glucose and 50 µg/mL of ampicillin at the final concentration.…”

Section: Oph Preparation and Reactionmentioning

confidence: 99%

“…is a homodimeric organophosphotriesterase that degrades a broad spectrum of neurotoxic OPs [15,16]. The use of OPH in bioremediation is of great interest due to its high turnover rate [17][18][19][20][21]. The OPH-expressing microorganism itself was also attempted to treat OPs as whole cell catalyst, but mass transport problems were not effectively solved yet [17,19,20].…”

Section: Introductionmentioning

confidence: 99%

Removal of neurotoxic ethyl parathion pesticide by two-stage chemical/enzymatic treatment system using Fenton’s reagent and organophosphorous hydrolase

Choi

Seo

Kang

et al. 2010

Korean J. Chem. Eng.

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Organophosphate compounds, which are essential ingredients of pesticide, plasticizer, air fuel, and chemical warfare agents, are serious neurotoxic hazardous materials. Therefore, diverse physical-chemical treatments have been attempted to degrade organophosphate compounds. In the present work, we propose a two-stage chemical and enzymatic treatment system. As a first stage, pretreatment of oxidation and coagulation using Fenton's reagent utilizing iron and hydrogen peroxide was employed. Preferentially, 1 mM ethyl parathion (EP) pesticide was largely (~80%) removed by Fenton's reagent reaction within 15 min. To remove residual EP, enzymatic treatment with organophosphorous hydrolase (OPH) from recombinant Escherichia coli was employed as a second stage. We successfully demonstrated that the proposed two-stage hybrid treatment process removed 1 mM environmental toxic EP efficiently (~98%) within 30 min.

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“…There are a number of methods that have been used for the degradation of organophosphates from water with appreciable success [6][7][8][9][10][11][12][13]. Ghosh et al [13] studied the hydrolysis of carboxylic esters such as Paraoxon using N-hydroxylamines and N-hydroxy amides in surfactants such as cationic micellar media.…”

Section: Introductionmentioning

confidence: 99%

“…Catalysis of this Paraoxon is by hydrolyzing phosphorus ester bonds, such as P-O and P-S bonds, through a hydrolytic mechanism that involves adding an activated water molecule at the phosphorus center [11]. More so, E. coli has been utilized to mineralize Paraoxon by co-expression of organophosphorus hydrolase (OPH) under trc promoter and Vitreoscilla hemoglobin (VHb) under the O 2 -dependent nar promoter [12]. Additionally, a strain of Pseudomonas putida was constructed, which was seen to efficiently degrade Paraoxon and utilize it as an energy source.…”

Section: Introductionmentioning

confidence: 99%

Reduction and Degradation of Paraoxon in Water Using Zero-Valent Iron Nanoparticles

et al. 2022

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Paraoxon is an emerging organophosphate pollutant that is commonly used as a pesticide and a drug, hence increasing the risk of contamination of water supplies. Its intensive use for vector control has led to pollutions in soil and water. Paraoxon is very toxic, with an LD50 of 2 to 30 mg/kg in rats. It can be metabolized in the body from parathion; thus, exposure can lead to serious health effects. In this study, zero valent iron (Fe°/ZVI NPs) nanoparticles were synthesized and investigated for the degradation of Paraoxon, a chemical warfare agent and insecticide, in an aqueous solution. The effects of solution pH, initial pollutant concentration, ZVI NPs dosage and contact time on mineralization efficiency were examined. Batch experiments demonstrated that 15 mg L−1 of Paraoxon was mineralized at degradation efficiencies of 75.9%, 63.9% and 48.9% after three-hour treatment with 6.0, 4.0 and 2.0% w/v Fe°, respectively. The calculated kinetic rate constant kobs was 0.4791 h−1, 0.4519 h−1 and 0.4175 h−1 after treating 10, 15 and 20 mg L−1 of Paraoxon solution with 6.0% w/v Fe, respectively. The degradation dynamics were described by the first-order kinetic law as evidenced by rate constants independent of the initial Paraoxon concentration. The degradation efficiency was strongly dependent on pH, increasing with a decrease in pH, with maximum removal at pH 4. p-nitrophenol was detected as a degradation product, suggesting cleavage of the O-P bond and hydrolysis as possible reaction processes. This study showed that Fe° particles have the potential for degrading Paraoxon.

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Cited by 38 publications

References 21 publications

Efficient cell surface display of organophosphorous hydrolase using N-terminal domain of ice nucleation protein in Escherichia coli

Efficient cell surface display of organophosphorous hydrolase using N-terminal domain of ice nucleation protein in Escherichia coli

Removal of neurotoxic ethyl parathion pesticide by two-stage chemical/enzymatic treatment system using Fenton’s reagent and organophosphorous hydrolase

Reduction and Degradation of Paraoxon in Water Using Zero-Valent Iron Nanoparticles

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