A streptomycete bacterium was isolated from a field soil sample previously treated with the insecticide isofenphos and found to be capable of growing on several commercial carbamate and organophosphate insecticides. These included carbofuran, cloethocarb, trimethacarb, isofenphos, fonofos, ethoprop, and phorate but not terbufos. As shown by Chromatographic analyses, the bacterium reduced the levels of isofenphos by 65–75% in a four-week period. Although the exact mechanism of degradation is not known, apparently it occurs by either an incidental type of metabolism or an abiotic process. Taxonomic characterization of this bacterium indicated it most nearly resemblesStreptomyces pilosus. A single plasmid with a molecular weight of 9,700 base pairs was obtained from the organism. It is not yet known if the presence of plasmid DNA contributes to the ability of the organism to grow on the pesticides.