Incorporation of 14C-Formaldehyde into Hexose Phosphate by Cell-free Extract of a Methanolutilizing Yeast,Candida sp. |
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Authors: | Takaaki Fujii Kenzo Tonomura |
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Institution: | Fermentation Research Institute, Inage, Chiba |
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Abstract: | The persistence and degradation of isoxathion 14C-labeled at the 5-position of the isoxazole ring were studied in three soil types under laboratory conditions. Persistence was influenced by soil type and moisture content; approx. half life at 30 ppmw dose level varied from 15 to 40 days in nonflooded models. In a flooded model isoxathion disappeared much faster. Isoxathion underwent biodegradation to a number of products with concomitant release of 14CO2. 3-Hydroxy-5-phenylisoxazole, 5-phenyl-4-oxazolin-2-one, benzoylacetamide and benzoic acid were the unequivocally identified metabolites; oxon derivative of isoxathion, 3-methoxy-5-phenylisoxazole, 2-methyl-5-phenyl-4-isoxazolin-3-one, 2-acetyl-5-phenyl-4-isoxazolin-3-one, 2, 5-diphenylpyrazine and acetophenone were tentatively identified as the minor products. None of these major products was persistent in soils. 3-Hydroxy-5-phenylisoxazole, the initial metabolite or hydrolyzate of isoxathion, was adsorbed to soil to a much greater extent than isoxathion, which explains the rapid disappearance of its fungicidal activity in soil. |
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Keywords: | chitinase Autographa californica multiple nucleopolyhedrovirus Sf-9 cells chitin oligosaccharide solid chitin |
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