School Of Environment And Earth Sciences

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    Mutagenic Effect in Vegetables by Pesticides
    (Krishi Sanskriti Publications, 2013) Nag, Shilpa; Jain, A.K.; M.S., Dhanya
    The advent of pesticides in vegetable crops is to control insects, pathogens and weeds aimed at increasing the crop yield, but the applied pesticides are not fully reaching the target pests. It escapes to environment or accumulates in crops resulting in some deleterious changes. The disturbances were observed in physiological and cytological levels of the affected plants by blocking mitosis and producing mitotic and meiotic chromosome abnormalities. Some pesticides like acetamiprid, carbendazim, chlorpyriphos, cypermethrin, dichlorvos, dicofol, dimethoate, fenvalarate, indoxcarb, mancozeb, monocrotophos, profenophos, quinalphos, zineb etc. proved to be mutagens. Researchers reported abnormalities like chromosomes with inactivated centromeres, isochromosome, picnosis, vagrant, stickiness, bridges, precocious separation and lagging chromosomes, reduction in mitotic index, micronuclei, multipolar cells, sister chromatid exchanges, c- mitosis are common in vegetables. Such abnormalities were observed in kharif vegetables like Lycopersicon esculentum, Capsicum annum, Solanum melongena, Abelmoschus esculentus, Cucumis sativus, Vicia faba, Phaseolus vulgaris and rabi vegetables like Allium cepa, Coriandrum sativum, Raphanus sativus, Solanum tuberosum, Pisum sativum etc. The pesticides act as potent environmental mutagens that possess a threat to cause alterations in genetic makeup in vegetables.
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    Laccase immobilized magnetic iron nanoparticles: Fabrication and its performance evaluation in chlorpyrifos degradation
    (Elsevier Ltd, 2017) Das, A.; Singh, J.; Yogalakshmi, K.N.
    Chlorpyrifos degradation was studied using laccase immobilized on magnetic iron nanoparticles (CENPs). The magnetic iron nanoparticles (MNPs) prepared by co-precipitation method were characterized using Transmission electron microscopy (TEM), Scanning electron microscopy- Energy dispersive spectroscopy (SEM-EDS) and Thermogravimetric analysis (TGA). The size of the nanoparticles ranged between 10 and 15 nm. The MNPs were coated with chitosan, surface modified with carbodiimide (EDAC) immobilized with laccase enzymes. The chlorpyrifos degradation studies were performed in batch studies under constant shaking for a period of 12 h. Results of the study showed that laccase immobilized on magnetic iron nanoparticles were effective in degrading more than 99% chlorpyrifos in 12 h at pH 7 and 60 ?C. In the overall degradation percentage, MNPs contributed to 32.3% of chlorpyrifos removal while ENPs resulted in 58.8% chlorpyrifos degradation. Immobilization of enzyme decreased the overall activity of the free enzyme. The CENPs showed 95% activity after five repeated washing and hence possess good reusability potential. ? 2017 Elsevier Ltd