摘要
氰氟草酯(Calofop-buty1)是一种芳氧苯氧羧酸酯类除草剂,其迁移、转化和分解等行为对环境及人类健康具有潜在危害.为了解其微生物代谢机制,从长期使用氰氟草酯的稻田土壤中分离到1株氰氟草酯降解菌株,命名为QDZ-B.菌株QDZ-B的16S rDNA基因序列长度为1 400 bp,在RDP数据库比对结果表明其与寡养食单胞菌属菌株的同源性最近,与模式菌株嗜麦寡养食单胞菌Stenotrophomonas maltophilia(AB008509)的同源性为99.8%.根据表型特征、生理生化特性和16S rDNA序列同源性分析,将菌株QDZ-B鉴定为寡养单胞菌属(Stenotrophomonas sp.).接种量为5%时,菌株QDZ-B在基础盐液体培养基中5 d对100 mg L-1氰氟草酯的降解率约为88.2%.菌株QDZ-B的降解效果与接种量成正相关,但接种量大于5%时,降解效率趋于平稳.菌株QDZ-B降解氰氟草酯的最适温度为30℃,最适pH为7.0.通过质谱分析鉴定了3个菌株QDZ-B降解氰氟草酯的代谢产物,分别为氰氟草酸、氰氟草酰胺和2-氟-3-对-乙氧基苯氧基苯酰胺.
Cyhalofop-butyl （CyB） is a widely used aryloxyphenoxy propanoate （AOPP） herbicide for weed control in rice fields. Although herbicides are typically applied to the crop and weed canopy, substantial quantities of the active ingredient penetrate to the soil surface. Therefore, great concerns have been raised about the occurrence and fate of the herbicides in the environment. A cyhalofop-butyL^-degrading bacterium strain, QDZ-B, was isolated from rice field soil that had been treated with cyhalofop-butyl for many years, and its 16S rRNA gene sequence （1 400 bp） was determined. The result of sequence analysis of the 16S rDNA gene revealed that strain QDZ-B displayed a high sequence similarity with Stenotrophomonas maltophilia （99.8%）. According to its morphological, physiological and biochemical properties and the homology analysis of 16S rDNA sequence, strain QDZ-B was identified as Stenotrophomonas sp. The degradation rate was about 88.2% when the strain with an inoculum size of 5% （V/V） was incubated at the concentration of 100 mg/L cyhalofop-butyl for 5 d. And large initial inoculum size could promote the degradation in the range of 5%. The optimal pH and temperature for cyhalofop-butyl degradation were 7.0 and 30 ℃, respectively. Three metabolites of cyhalofop-butyl degradation by strain QDZ-B were identified as cyhalofop acid, cyhalofop amide and 2-fluoro-（3-p-ethoxy-phenoxy） benzamide by HPLC/MS analysis. Fig 11, Ref 21
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2011年第6期869-875,共7页
Chinese Journal of Applied and Environmental Biology
基金
国家自然科学基金项目(No.30970099)
农业部技术成果转化基金项目(No.2009GB23600516)资助~~
关键词
氰氟草酯
除草剂
微生物降解
寡养单胞菌属
降解产物
cyhalofop-butyl
herbicide
biodegradation
Stenotrophomonas sp.
metabolite product
作者简介
通讯作者Corresponding author（E—mail：zhengjw@njau．edu．cn）
