Microbial degradation of paraquat sorbed to plant residues

• Published in: Journal of agricultural and food chemistry Vol. 43; no. 5; pp. 1343 - 1347
• Main Authors: Lee, Seog June, Katayama, Arata, Kimura, Makoto
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.05.1995
• Subjects: Agronomy. Soil science and plant productions; ANAEROBIOSE; ANAEROBIOSIS; ASTRAGALUS; Biochemistry and biology; BIODEGRADACION; BIODEGRADATION; Biological and medical sciences; Chemical, physicochemical, biochemical and biological properties; CHLORURE D'AMMONIUM; CLORURO AMONICO; DISPONIBILIDAD DE NUTRIENTES; DISPONIBILITE D'ELEMENT NUTRITIF; FLORA DEL SUELO; FLORE DU SOL; Fundamental and applied biological sciences. Psychology; HERBICIDAS; HERBICIDE; Microbiology; MICROORGANISME; MICROORGANISMOS; NITRATE DE SODIUM; NITRATO DE SODIO; PAILLE DE RIZ; PAJA DE ARROZ; PARACUAT; PARAQUAT; Physics, chemistry, biochemistry and biology of agricultural and forest soils; RESIDU; RESIDU DE RECOLTE; RESIDUOS; RESIDUOS DE COSECHAS; Soil science; SORCION; SORPTION; UMBELLIFERAE; UREA; UREE; Quaternary ammonium compound; Biodegradation; Laboratory study; Cultivated soil; Vegetal microorganism relation; Paraquat; Microorganism; Herbicide; Site of action
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf00053a040

It was demonstrated that paraquat (1,1'-dimethyl-4,4'-bipyridynium dichloride) sorbed to plant residues was degraded by natural microbial populations associated with plants and/or soil under laboratory conditions. The microorganisms associated with plants showed a higher degradation rate than those from soil. The degradation rate was higher in rice straw (C/N ratio = 53) than in dropwort (C/N = 20) and Chinese milk vetch (C/N = 17). Urea, ammonium chloride, and sodium nitrate suppressed the paraquat degradation rate by microorganisms associated with rice straw suggesting a relationship to nitrogen metabolism. The degradation rate was much higher under aerobic conditions than under anaerobic conditions. When rice straw containing sorbed paraquat was placed on the surface of soil or mixed with soil, the herbicide was degraded under the former condition but not under the latter condition. Monopyridone (1',2'-dihydro-1,1'-dimethyl-2'-oxo 4,4'bipyridynium ion) and 14CO2 were detected as metabolites in rice straw spiked with [methyl-14C2]-paraquat