MICROBIAL-METABOLISM OF FLUAZIFOP-BUTYL

A microbial mixed culture able to grow on fluazifop-butyl and fluazifop was isolated. Fluazifop degradation by this microbial population was studied either when the herbicide was applied as the sole carbon source or in the presence of a second carbon source (sodium acetate or sodium propionate). The degradation rate was enhanced by sodium propionate. The degradation was found to be stereoselective. The S-enantiomer of fluazifop was degraded at a much higher rate than the R-enantiomer. Fluazifop disappearance was accompanied by formation of three metabolites which were identified by UV, IR, MS and NMR analyses. The metabolites were shown to be : 4-(5-trifluoromethyl-2-pyridyl) oxyphenol, 5-trifluoromethyl-2-hydroxypyridine and 2-(5-trifluoromethyl pyridyl) hydroxy acetate.