摘要
采用富集培养的方法,从农药厂排水渠底泥中分离筛选出一株能高效降解甲维盐·毒死蜱的细菌XK-1,经生理生化和16Sr DNA鉴定其属于克雷伯氏杆菌（Klebsiella）,命名为Klebsiella XK-1。研究结果表明,该菌株对甲维盐·毒死蜱有较高的耐受性,在甲维盐·毒死蜱浓度达到500 mg/L时仍有较好的降解效果,降解效率达71.6%,最适甲维盐·毒死蜱降解浓度为300 mg/L,降解效率可高达96.8%;最适生长温度为30℃,对低温（低于10℃）和高温（高于40℃）敏感;p H适应范围较广为6.0~8.0,对甲维盐·毒死蜱的降解效率为81.3%~93.2%;最适投菌量为7%和通气量为300 m L。同时,将菌株XK-1进行模拟土壤体系中40%甲维盐·毒死蜱的降解实验,发现40%甲维盐·毒死蜱在土壤中的降解以微生物降解为主,化学水解为辅;菌株XK-1对甲维盐和毒死蜱的降解规律符合一级动力学方程,其对甲维盐和毒死蜱的降解半衰期分别为2.4 d和2.6 d。综上所述,菌株XK-1能高效降解甲维盐·毒死蜱,在生物修复农药污染土壤方面具有很好的应用前景。
With the method of enrichment cultivation, a bacterial strain, identified as Klebsiella by physiology, biochemistry and 16SrDNA analyses and named as Klebsiella XK-1, was isolated and screened from the drainage sediment of a pesticide plant to degrade emamectin benzoate and chlorpyrifos. The research showed that when the concentrations of emamectin benzoate and chlorpyrifos indicating that Klebsiella XK-1 has high tolerance and were 500 mg/L, the degradation efficiency could reach 71.6%, could degrade emamectin benzoate and chlorpyrifos efficiently. The optimum degradation efficiency was 96.8% when the concentration was 300 mg/L. Klebsiella XK-1 was sensitive to low （〈10℃） and high （〉40℃） temperatures, and the optimum temperature was 30℃. At a wide range of test pH （6.0 8.0）, the degradation efficiency ranged from 81.3% to 93.2%. The optimum inoculum bacterial concentration was 7%, and ventilation was 300 mL. Klebsiella XK-1 was used to degrade synthetic soils containing 40% emamectin benzoate and chlorpyrifos, and the results indicate that the degradation follows the first-order kinetic equation, and mainly relies on microorganisms supplemented by chemical hydrolysis. The half-life degradation time for emamectin benzoate and chlorpyrifos was 2.4 d and 2.6 d, respectively. In conclusion, Klebsiella XK-1 could degrade emamectin benzoate and chlorpyrifos efficiently and had great potential for bioremediation of pesticide-contaminated soils.
出处
《城市环境与城市生态》
CAS
2016年第3期1-6,共6页
Urban Environment & Urban Ecology
基金
科技惠民计划项目蓟县水源保护区农村生态环境改善科技惠民综合示范项目(2012GS120201)
山东省自然基金(ZR2013EEQ009)
关键词
甲维盐·毒死蜱
降解菌
降解特性
emamectin benzoate and chlorpyrifos
degradation bacterium
degradation characteristic
