摘要
有机磷杀虫剂杀扑磷对防治蚧壳虫有特效,常用于柑橘类果树防治但其残留有毒有害,自然界降解速度比较缓慢.本研究分离并分类鉴定了能高效降解杀扑磷的菌株,进一步采用Box-Benhnken法设计3因素3水平的响应面试验优化降解条件.结果显示,从富集培养基中分离到了一株杀扑磷高效降解细菌MS1-2,经鉴定为膝形假单胞菌(Pseudomonas geniculata);单因素选择温度、NaCl浓度和pH,通过检测杀扑磷残留量对杀扑磷降解条件进行响应面优化,转速设置为100 r/min,接种量为0.4%时,温度和Na Cl浓度为主要影响因素,pH为次要因素,最佳降解条件为温度29.74℃,pH 6.48,Na Cl浓度0.63%.在此条件下培养24 h,杀扑磷从100 mg/L降解到57.73 mg/L,降解率为42.27%,比优化前提高了6个百分点.因此菌株MS1-2能有效降解杀扑磷,优化降解条件后降解率有所提高.
Organophosphorus pesticides including methidathion are generally highly toxic with residues harmful to health but slow in degradation in nature. This research aimed to isolate a bacterium which can degrade methidathion efficiently, and optimize its conditions of degradation by the response surface method. The strain MS1-1 was enriched with enrichment culture and purified by the streaked plate, and determined based on the 16 SrDNA sequence analysis. Degradation of methidathion was determined by high performance liquid chromatography at 24 hours after inoculation. A bacterial strain MS1- 2 that could effectively degrade methidathion was isolated from soil and identified as Pseudomonas geniculata. A 3-factor, 3-level Box-Benhnken experiment was designed to select the temperature, pH and NaCl concentration. The optimal conditions for methidathion degeneration were found to be rotational speed of shaking incubator of 100 r/min, inoculation amount of 0.4%, inoculum OD600 of 0.53, culture temperature of 29.74 °C, pH of 6.48 and Na Cl concentration of 0.63%. The degradation rat e was 42.27% after culture for 24 h under these conditions, 6% higher than that in previous optimization.
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2016年第2期224-229,共6页
Chinese Journal of Applied and Environmental Biology
基金
"十二五"支撑计划项目(2014BA D02B02)
四川省科技厅项目(2012GZ0008
2014GZX0005
2013GZ0058
2013GZX0161-3
2015J PT0 032
15010302)资助~~
关键词
杀扑磷
降解
膝形假单胞菌
响应面优化
methidathion
degradation
Pseudomonas geniculata
response surface optimization
