Effects of Ionic Strength and Sesquioxides on Adsorption of Toxin of Bacillus thuringiensis *** on Soils

作     者：FU Qing-Ling PENG Ya-Wen HUANG Tao HU Hong-Qing DENG Ya-Li YU Xia 

作者机构：Key Laboratory of Subtropical Agricultural Resource and EnvironmentMinistry of AgricultureHuazhong AgriculturalUniversityWuhan 430070(China) 

出 版 物：《Pedosphere》 (土壤圈（英文版）)

年 卷 期：2012年第22卷第1期

页      面：96-102页

核心收录：

学科分类：081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 09[农学] 0904[农学-植物保护] 070303[理学-有机化学] 0703[理学-化学] 

基　　金：Supported by the National Natural Science Foundation of China (Nos. 41001140 and 40671087) 

主　　题：Al oxides Fe oxides lateritic red soil paddy soil supporting electrolyte 

摘      要：Chemical reactions and fate of the toxins of Bacillus thuringiensis （Bt） in the soil environment are causing increasing concerns due to the large-scale cultivation of transgenic Bt plants. In this study, the effect of ionic strength （0-1 000 mmol kg-1） adjusted by NaCl or CaCl2 on adsorption of Bt toxin by a lateritic red soil, a paddy soil and these soils after chemical removal of organic-bound or free Fe and Al oxides, as well as by pure minerals （goethite, hematite and gibbsite） which are widespread in these soils, were studied. The results indicated that when the supporting electrolyte was NaCl, the adsorption of Bt toxin by the lateritic red soil and paddy soil increased rapidly until the ionic strength reached 250 mmol kg-1 and then gradually slowed down with the increase of ionic strength; while in ease the supporting electrolyte was CaCl2, the adsorption of Bt toxin enhanced significantly at low ionic strength （〈 10 mmol kg-1） and then decreased as the ionic strength increased. The adsorption of Bt toxin by the tested minerals and soils after the removal of organic-bound or free Fe and Al oxides also increased with increasing ionic strength controlled by NaCl. Removing organic-bound Fe and Al oxides obviously increased the adsorption of Bt toxin in the tested soils. Differently, removing free Fe and Al oxides increased the Bt adsorption by the paddy soil, but decreased the adsorption by the lateritic red soil. The study indicated that the varieties of ionic strength and the presence of Ve and Al oxides affected the adsorption of Bt toxin by the soils, which would contribute to the further understanding of the fate of Bt toxin in the soil environment and provide references for the ecological risk assessment of transgenic Bt plants.