苯醚甲环唑降解菌B2的分离、鉴定及其降解特性

从长期生产苯醚甲环唑的农药厂污泥中分离到1株能以苯醚甲环唑为唯一碳源生长的细菌,命名为B2.根据其生理生化特征和16S rRNA基因序列相似性分析,将该菌株鉴定为剑菌属(Ensifer sp.).菌株B2在24h内降解100mg/L的苯醚甲环唑的效率达85%以上.该菌株降解苯醚甲环唑的最适pH值为7.0,最适温度为30~35℃,降解速率与初始接种量呈正相关,与初始农药浓度呈负相关.基础盐培养基中,B2对初始浓度>400mg/L的苯醚甲环唑几乎无降解作用.

Isolation, identification and characteristics of a difenoconazole-degrading bacterial strain B2

A bacteria strain B2 capable of utilizing difenoconazole as sole carbon source was isolated from sludge collected from a pesticide manufacturer which has been producing difenoconazole for many years. It was identified as Ensifer sp. according to its physiological-biochemical properties and the analysis of its 16S rRNA gene sequence (GenBank Accession No. EU303300). Above 85% of 100mg/L difenoconazole was degraded by strain B2 within 24h. The optimal pH and temperature for degradation were 7.0 and 30~35℃ respectively. The degrading rate showed a positive correlation with the amount of initial inoculum size while a negative correlation with the initial concentration of difenoconazole. No degradation occurred if the initial concentration of difenoconazole excessed 400mg/L in mineral salt medium.