Metabolism of Nitrophenols in Flooded Soils1
- Sudhakar-Barik and
- N. Sethunathan2
Nitrophenols (p-,o-, and m-isomers and 2,4-dinitrophenol) disappeared fairly rapidly from flooded alluvial and organic matter-rich acid sulfate (pokkali) soils inoculated with parathion (O,O-diethyl O,p-nitrophenyl phosphorothioate)-enrichment cultures from the respective soils. Nitrite, one of the reported end-products of nitrophenol (O,O-dimethyl O,p-nitrophenyl phosphorothioate) metabolism, accumulated only in inoculated alluvial soil, irrespective of the type of nitrophenol added. In an isotope study, ring cleavage of p-nitrophenol leading to carbon dioxide was demonstrated in flooded soils inoculated with parathion-enrichment culture, particularly under stirred conditions. Nitrophenols decomposed also in uninoculated samples of both soil types, though slowly as compared to inoculated soils; but nitrite and carbon dioxide were not formed. Resting cells of a bacterium, Pseudomonas sp. ATCC 29353, readily hydrolyzed parathion and then liberated nitrite from p-nitrophenol. In cell-free suspension, the reaction ceased at the p-nitrophenol stage. In bacterial cultures, parathion was hydrolyzed without proliferation while subsequent degradation of p-nitrophenol involved metabolism leading to bacterial enrichment.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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