蜡状芽孢杆菌HY-1降解甲基对硫磷和毒死蜱的影响因素研究

采用富集驯化培养和紫外分光光度计定量的方法,从农药生产企业的废水处理系统中分离筛选出1株能够降解甲基对硫磷和毒死蜱的蜡状芽孢杆菌(Bacilluscereus)HY-1,并系统研究了影响其降解甲基对硫磷和毒死蜱的主要因素。研究表明,菌株HY-1能够利用甲基对硫磷和毒死蜱为唯一磷源降解农药。HY-1降解甲基对硫磷的适宜条件为:培养温度30～35℃,pH为6～8,甲基对硫磷初始浓度为10～50mg·L-1,接种量20%(体积比,菌体密度:稀释到菌悬母液(OD600=3.0)的0.8～1倍),添加葡萄糖不能促进菌株对甲基对硫磷的降解。HY-1降解毒死蜱的适宜条件为:葡萄糖浓度6g·L-1,培养温度30～35℃,pH为7.0,毒死蜱初始浓度80～200mg·L-1,接种量20%(体积比,菌体密度:稀释到菌悬母液(OD600=3.0)的0.8～1倍)。结果表明,HY-1菌株降解甲基对硫磷和毒死蜱的适宜条件相类似,只是降解所需的最适葡萄糖浓度和底物浓度不同。

Degradative Characteristics of Bacillus cereus HY-1 to Methyl-parathion and Chlorpyrifos

A bacterial strain,Bacillus cereus HY-1,was isolated from the treatment system of the pesticide enterprises and its degradative characteristics to methyl-parathion and chlorpyrifos were studied by using the methods of enrichment culturing and the ultraviolet spec-trophotometer determination.The results showed that the bacteria could utilize the methyl-parathion or chlorpyrifos as the unique phosphorus source.The optimal conditions for degrading methyl-parathion were as follows:the temperature of 30～35℃,theinitial pH of 6～8,the initial methyl-parathion concentration of 10～50 mg·L~(-1) and the inoculation amount of 20％in the experiment(v／v).The results also indicated that the optimal conditions for degrading chlorpyrifos was similar as above,except the different concentration of glucose or the substrate concentra-tion.