Microbial degradation of organophosphate pesticides is of particular interest because of the high mammalian toxicity of such compounds and their widespread and extensive use. It has been relatively easy for some organophosphates such as parathion to isolate degrading bacteria. However, it has been problematic isolating a degrading strain for chlorpyrifos, which has been widely used for agricultural and household pest control since 1965. The objectives of the experiments were to isolate degrading strains fro...