Bt毒素在三种矿物表面的吸附与解吸  

Adsorption and desorption of Bt toxin on three kinds of minerals

作　　者：周学永[1] 高建保[1] 蔡鹏[2] 黄巧云[2] 

机构地区：[1]武汉科技大学湖北省高温陶瓷与耐火材料重点实验室 [2]华中农业大学农业微生物国家重点实验室,武汉430070

出　　处：《应用生态学报》2008年第5期1144-1148,共5页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(40271064,30170032);天津市自然科学基金项目(08JCZDJC18800);湖北省教育厅青年基金项目(Q200611007);武汉科技大学重点资助项目(2006XZ4)

摘　　要：研究了Bt库斯塔克亚种(kurstaki)毒素(65kDa)在高岭土、针铁矿和氧化硅表面的吸附和解吸特性.结果表明:在磷酸盐缓冲体系(pH8)中,3种矿物的等温吸附曲线均符合Langmuir方程(R2>0.9661),它们对Bt毒素的吸附顺序为:针铁矿(高岭土(二氧化硅.矿物对Bt毒素的吸附1h就基本达到了吸附平衡.在pH6～8范围内,针铁矿、高岭土和二氧化硅对Bt毒素的吸附量随pH值的升高而降低.10℃～50℃范围内,针铁矿和氧化硅对Bt毒素吸附量随温度升高有所下降(8.39%和47.06%),高岭土对Bt毒素吸附则略有升高(5.91%).红外光谱分析显示,Bt毒素被矿物吸附后结构仅有微小变化.被矿物吸附的Bt毒素不易被去离子水解吸,水洗3次总解吸率为28.48%～42.04%.This paper studied the characteristics of the adsorption and desorption of Bt （Bacillus thuringiensis） toxin on goethite, kaolinite, and silica. The results showed that in phosphate buffer （pH 8 ）, the adsorption isotherms of Bt toxin on the test minerals followed Langmuir equation （R2 〉0. 9661 ）, and the adsorbed amounts were in the order of goethite 〉 kaolinite 〉 silica. The Bt toxin was easily adsorbed on the minerals, and the adsorption could reach equilibrium after 1 hour. Within the range of pH 6-8, the amounts of Bt toxin adsorbed on goethite, kaolinite and silica decreased with increasing pH ; in the range of 10 ℃-50 ℃, the amounts of the toxin adsorbed on goethite and silica decreased by 8.39% and 47.06%, respectively, while that on kaolinite increased slightly （5.91% ）. The infrared absorption spectrum showed that there was only a minor alteration of Bt toxin after adsorption. The toxin adsorbed on the minerals was not easily desorbed by deionised water, with the desorption rate ranged from 28.48% to 42. 04% after three times washing.

关 键 词：苏云金芽胞杆菌 毒素 矿物 吸附 解吸 

分 类 号：S476[农业科学—农业昆虫与害虫防治]