Isolation of beta-cypermethrin degrading bacterium and its degradation characteristics

A beta-cypermethrin(β-CP)degrading bacterium that designated as DL-3was isolated from the activated sludge soil samples of a pesticide factory.Based on the morphological,physiological and biochemical properties,and 16SrDNA gene sequence analysis,the isolate was identified as Bacillus sp..It could utilize 100mg/Lβ-CP as the sole source of carbon and energy for growth,and degrade67.5% of it after 7d.The optimum degradation condition was 37 ℃ and pH 7.0,respectively,and the maximum tolerance concentration ofβ-CP was 400mg/L.In addition,degradation ability of DL-3was greatly improved when additional nutrients were added.It is potentially useful in bioremediation of pyrethroids in contaminated environments.