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作 者 ：周学永^{1, 2};高建保¹;蔡鹏³;黄巧云³

期 刊 ：应用生态学报 2008年 19卷 05期 页码：1144-1148

摘 要 ： 研究了Bt库斯塔克亚种(kurstaki）毒素（65 kDa）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（pH 8）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1 h就基本达到了吸附平衡.在pH 6～8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%.

Abstract: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oxin 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.

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