摘要
从农药厂污水处理池的活性污泥中分离到1株能以烟嘧磺隆为唯一碳源生长的细菌,命名为YN-8。根据表型特征、生理生化特性及16S r RNA序列同源性分析,将该菌株初步鉴定为假单胞菌属(Pseudomonas sp.)。YN-8能在以烟嘧磺隆为唯一碳源的基础盐液体培养基中生长,培养7 d,烟嘧磺隆的去除率达65.4%。该菌降解烟嘧磺隆的最适p H值为7.0,最佳接种量为5%,最适质量浓度为100 mg/L。当金属离子浓度为1 mmol/L时,Co2+和Ni2+抑制菌株对烟嘧磺隆的降解。通过液相色谱-质谱联用检测菌株降解烟嘧磺隆的代谢产物,初步推测烟嘧磺隆的降解途径为磺酰脲桥被打断,生成2-氨基-4,6-二甲氧基嘧啶和3-(二甲基烟酰胺)吡啶-2-基磺酰氨基甲酸。
A bacterial strain YN-8, capable o f utilizing nicosulfuron as sole carbon, was isolated from activated sludge collected from wastewater-treating system of a pesticide manufacturer. This strain was identified as Pseudomonas sp. according to its morphological, physiological and biochemical analysis and the analysis of its 16 S r RNA gene sequence. This strain could degrade nicosulfuron in its 100 mg/L liquor medium, with degradation efficiency reaching 65.4% in 7 days. The optimum p H,inoculation and concentration for nicosulfuron degradation by strain YN-8 were 7.0, 5% and 100 mg/L, respectively. In the tested metal ions, Co2＋and Ni2＋could inhibit the nicosulfuron degradation rate. According to the analysis of the metabolites detected by liquid chromatography-mass spectrometry, we proposed the following pathway of nicusulfuron biodegradation by strain： cleavage of the sulfonylurea bridge and generate 3-（dimethylcarbamoyl） pyridin-2-ylsulfonylcarbamic acid and 2-Amino-4, 6-dimethoxypyrimidine.
出处
《环境科技》
2015年第4期12-17,21,共7页
Environmental Science and Technology
关键词
烟嘧磺隆
假单胞菌属
生物降解
降解途径
Nicosulfuron
Pseudomonas sp.
Biodegradation
Metabolic pathway
