噻吩磺隆降解菌FLX的分离鉴定及降解特性

Separation identification and degradation characteristics of thifensulfuron-methyl degradation bacteria FLX

从生产噻吩磺隆的农药厂内土壤中采取土样,经驯化富集后筛选到1株能高效降解噻吩磺隆的细菌FLX,根据表型特征、生理生化特性及16SrDNA分析,鉴定FLX初步为寡养单胞菌(Stenotrophomonas sp.).FLX能在含50mg/L噻吩磺隆的基础盐液体培养基中降解噻吩磺隆,48h降解率达83.34%.FLX降解噻吩磺隆的最适pH值为7.0,最适温度为35℃,在所试的金属离子中,Zn2+、Al3+、Cu2+、Ba2+、Fe3+等对FLX的降解影响较小;Hg2+,Co2+则抑制FLX的生长与降解.酶的定域实验表明,该菌中噻吩磺隆水解酶为胞内酶.

A Strain of bacterium FLX capable of highly degrading thifensulfuron-methyl was screened from the soil sample collected from a producing thifensulfuron-rnethyl pesticide plant after taming and enrichment. Based on analysis of phenotype, physiological and biochemical characters and 16S rDNA, FLX was identified preliminarily as Stenotrophomonas sp. FLX could degrade thifensulfuron-methyl in its 50mg/L liquor medium, with 83.34% degrading rate in 48h, and the optimal pH value and temperature of 7.0 and 35℃. In the tested metal ions, Zn^2＋. Al^3＋. Cu^2＋, Ba^2＋, Fe^3＋ had little influence on FLX; while Hg^2＋, Co^2＋ inhibited its growth and degradation. The distribution experiment showed that the thifensulfuron-methyl hydrolysis enzyme in the bacterium was endoenzyme.