School Of Environment And Earth Sciences

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Subject: search.filters.subject.Laccase

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    Amino-functionalized Magnetic Iron Nanoparticles As a Carrier for Laccase Enzyme and Its Potential to Degrade Chlorpyrifos in Contaminated Soil: Fate and Kinetics
    (Springer Science and Business Media Deutschland GmbH, 2022-04-14T00:00:00) Das, Anamika; Yogalakshmi, Kn
    The present study utilizes the covalent-crosslinking method to immobilize the�laccase enzyme on magnetic iron nanoparticles�and further assess its potential in degrading�chlorpyrifos in pesticide spiked�soil. The soil texture analysis revealed the presence of clay, silt and sand accounting to�7.1%, 14.3%, and 78.6%, respectively. The degradation of chlorpyrifos in spiked soil�using laccase enzyme�immobilized�magnetic iron nanoparticles was measured for 60�days�in a batch process. The results revealed a gradual increase in degradation efficiency showing around�29.3%, 43.8%, 56.3%, and 67.3% at the 20th, 30th, 40th, and 50th day�of incubation. A maximum degradation of�83.6% was observed on the 60th day of incubation. Intermediate products 2,4-bis(1,1 dimethylethyl) phenol, 1,2 benzenedicarboxylic acid, bis(2-methyl propyl) ester�and�piperidine confirmed the degradation of chlorpyrifos in soil. The piperidine originated in the chromatogram between�20�40�days of incubation and diminished later. Chlorpyrifos degradation followed pseudo first-order kinetics with a R2 of 0.96. Further, the nanoparticles showed no negative�impact on soil bacterial population during the antibacterial assay. The study confirms the degradation of chlorpyrifos in contaminated soil using laccase-immobilized nanoparticles. � 2022, The Author(s), under exclusive licence to Springer Nature Switzerland AG.
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    Degradation of chlorpyrifos in soil using laccase immobilized iron oxide nanoparticles and their competent role in deterring the mobility of chlorpyrifos
    (Elsevier Ltd, 2020) Das A.; Jaswal V.; Yogalakshmi K.N.
    Covalent-immobilization of the laccase enzyme onto the iron oxide nanoparticles was achieved using N-(3-Dimethylaminopropyl)-N?-ethylcarbodiimide hydrochloride (EDAC) as cross-linkers. The presence of sulphur moeity in the laccase immobilized nanoparticles (LNPs) observed through Scanning Electron Microscopy- Energy dispersive X-ray spectroscopy (SEM-EDS) spectra confirmed the immobilization of laccase enzyme. The TEM analysis of iron oxide nanoparticles (FNPs), chitosan coated iron nanoparticles (CNPs) and laccase immobilized nanoparticles (LNPs) confirmed their sizes around 12, 15 and 20 nm, respectively. The effect of LNPs in degrading chlorpyrifos under field conditions was studied by simulating the conditions in a column. Column A, which was used as control showed more leaching of chlorpyrifos as compared to column B containing LNPs. The sorption coefficient (Kd) value obtained for control (column A) and LNPs containing column B were 21.6 and 112.3 L/kg, respectively. LNPs altered the Kd values of soil thereby showing lesser leaching potential. Higher the Kd value, lesser will be the leaching potential in the ground water. Copper in laccase enzyme resulted in hydrolysis of chlorpyrifos. Chitosan used for coating on FNPs and soil organic matter resulted in the adsoption of chlorpyrifos. Current results will allow a better assessment of the role of LNPs as a competent deterrent in chlorpyrifos mobility and degradation.
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    Comparative Analysis of Laccase Immobilization on Magnetic Iron Nanoparticles using Two Activating Agents:EDAC and Cyanuric Chloride
    (Tamil Nadu Scientific Research Organization (TNSRO), 2016) Das, Anamika; Singh, Jatinder; Yogalakshmi, K. N.
    Surface modification improves the covalent bonding of enzymes onto the magnetic nanoparticles. The present study aims to evaluate the effect of surface activators (EDAC (1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide) and Cyanuric chloride) in immobilization of enzymes. Nanoparticles prepared by co-precipitation method ranged insize from 15-20 nm. The nanoparticles possessed crystalline property as confirmed by the XRD (X-ray powder diffraction) peaks. SEM-EDS (Scanning Electron Microscopy- Energy Dispersive X-ray Spectroscopy) analysis of EDAC and cyanuric acid activated nanoparticles showed atomic sulphur percent of 0.08% and 0.02%, respectively. It is concluded that EDACwas more successful in loading more enzymes than cyanuric acid. Bradford estimation of the unbound protein after first wash for ENP-EDAC and ENP-CC was 29.1 μg/mL and 132.1 μg/mL, respectively. EDAC is a potential surface modifier for enzyme immobilization process.