Dibutyl phthalate (DBP) was more efficiently degraded by cutinase compared to yeast esterase; i.e. almost 80% of initial DBP (500 mg l(-1)) was decomposed within 7.5 h, and nearly 50% of the degraded DBP disappeared within the initial 30 min. The toxicity of the final DBP degradation products were investigated using various recombinant bioluminescent bacteria. Butyl methyl phthalate, the major product of degradation by the esterase, was an oxidative toxic hazard that damaged protein synthesis.