联苯菊酯降解菌的筛选、鉴定及降解特性研究

联苯菊酯是一种广谱高效杀虫剂,大规模的应用使其广泛残留在环境中,因此筛选联苯菊酯的高效降解菌具有重要意义。从扬州农药厂附近的地表土壤取样,利用富集驯化培养分离得到一株编号为S8的降解细菌,经表形特征、生理生化特性和16SrDNA序列分析其为醋酸钙不动杆菌(Acinetobacter calcoaceticus),该菌株在pH7.0和30℃的条件下,对100mg·L-1联苯菊酯的3d降解率达56.4%,半衰期为60.7h。其最适生长条件为:pH6.0～8.0,温度30～35℃,接种量5%。研究结果可为今后治理联苯菊酯残留污染提供理论参考。

Isolation, Identification and Biodegradation Characteristics of a Bacterial Strain able to Degrade Bifenthrin

Bifenthrin(BF)is a broad-spectrum and highly efficient synthetic insecticide.However,the difficulty of its natural degradation makes it widely remain in the environment,which causes many critical environmental problems.Microbial biodegradation of pesticide residues,especially bacterial biodegradation,is the main way in repair of such sort of environment pollution.Although there have been some reports on the pyrethroid insecticide degradation bacteria,the degradation effect and stability of those bacteria still need to be explored.Therefore,the screen for efficient BF degrading bacteria has great research significance.In this study,a BF degrading bacterium designated as S8 was isolated,purified and sorted from the surface soil near to the Yangzhou Pesticide Plant.The bacterial strain S8 was identified as Acinetobacter calcoaceticus,according to its morphological,physiological and biochemical characterization,as well as the sequence analysis of its 16S rDNA.The BF degradation reached equilibrium at 72 h and the degradation rate was 56.4%(initial concentration of 100 mg·L-1) with half lives of 2.53 d under the conditions of pH7.0 and 30 ℃.The optimal conditions for BF degradation were at pH6.0～8.0,30～35 ℃ and with 5% inoculation.The results indicated that the BF-degrading strain S8 had great application potential for the future bioremediation of environmental contamination by BF.