Isolation and identification of two pyrethroid pesticides degradation strains and research of degradative capabilities

Two strains named Q-7 and G-04 capable of a broad spectrum degrading of pyrethroid pesticides were isolated from the plowlandsoil by using enrichment culture,gradient method and the determination of pyrethroid pesticides degradation rate.Based on the morphology,physio- biochemical characteristics,and 16 S rRNA sequence analysis,strain Q- 7 was identified as Bacillus cereus,strain G- 04 was identified as Bacillus licheniformis.Two strains showed a strong ability of resistance to the pesticides for growing in liquid medium which contains β- cypermethrin,fenvalerate,permethrin and bifenthrin with a total concentration of 640 mg / L.Two strains could degrade β- cypermethrin,fenvalerate,permethrin and bifenthrin with the initial concentration of 50 mg / L simultaneously,the degradation efficiency of β- cypermethrin,fenvalerate,permethrin,bifenthrin by stain Q-7 and stain G-04 respectively reached 48.31%,64.31%,33.46%,26.52% and 66.94%,45.04%,29.40%,26.40%within 72 hours.The results showed that the strain Q-7 and strain G-04 possessed capability of broad spectrum degradation of pyrethroid pesticides,could be used as good repair of pyrethroid pesticide environmental pollution microorganism resources.