Microbial transformation of the pyrethroid insecticides: permethrin, deltamethrin, fastac, fenvalerate, and fluvalinate.

Pure cultures of Bacillus cereus, Pseudomonas fluorescens, and Achromobacter sp. were shown to transform five pyrethroid insecticides in the presence of Tween 80. One of the major products, 3-phenoxybenzoic acid, was further transformed to 4-hydroxy-3-phenoxybenzoic acid. Permethrin was the most rapidly transformed of the pyrethroids, with a half-life of less than 5 days.