A bacterium HS-A32 capable of degrading methamidophos was isolated from long - term organophosphate pesticides polluted soil. This strain can use methamidophos as the sole carbon and nitrogen source. The optimal growth conditions including temperature, pH and concentration of MAP were determined, i. e., 30°C, pH 7.0 and 1 000 mg/L MAP. The rate of degrading MAP was 82% within 2 days, and NH4+ could be detected by thin layer chromatography (TLC) with DNS-Cl. HS-A32 could also degrade other organophosphate pesticides, such as methyl parathion. S...