Adsorption and Insecticidal Activity of Toxin from Bacillus thuringiensis on Rectorite  

作　　者：ZHOU Xue-Yong HUANG Qiao-Yun CAI Peng YU Zi-Niu 

机构地区：[1]Hubei Province Key Laboratory of Refractories and Ceramics, Wuhan University of Science and Technology, Wuhan 430081 （China）. [2]College of Biotechnology and Chemical Engineering, Tianjin University of Technology, Tianjin 300191 （China） [3]State Key Laboratory of Agricultural Microbiology, College of Resources and Environment, Huazhong Agricultural Uni- versity, Wuhan 430070 （China）

出　　处：《Pedosphere》2007年第4期513-521,共9页土壤圈（英文版）

基　　金：the National Natural Science Foundation of China (Nos.40271064 and 30170032);the Natural Science Foundation of Tianjin,China (No.05YFJMJC05100);the Scientific Research Project of the Education Administration of Hubei Province,China (No.Q200611007);the Key Research Program of Wuhan University of Science and Technology,China (No.2006XZ4).

摘　　要：The adsorption and desorption of the toxin from Bacillus thuringiensis strain WG-001 on rectorite were studied at different toxin and/or rectorite concentrations, pH values and temperatures. The insecticidal activity of the adsorbed toxin was evaluated by determining the lethal concentration to kill 50% of the larvae of Heliothis armigera （LC50）. The adsorption of the toxin on rectorite in sodium carbonate buffer （pH 9） reached equilibrium within 0.5-1.0 h and the adsorption isotherm of the toxin followed the Langmuir equation （R^2 〉 0.99）. In the pH range from 9 to 11 （carbonate buffer）, the adsorbed toxin decreased with increasing pH. The adsorption amounts decreased with increasing rectorite：toxin ratio. The adsorption was not significantly affected by the temperature between 10 and 50 ℃. The X- ray diffraction analysis indicated occurrence of the intercalation of the rectorite by the toxin. The infrared absorption spectrum showed that the binding of the toxin did not alter its structure. The LC50 wlues of the adsorbed toxin were smaller than those of the free toxin. The rectorite protected the toxin from ultraviolet irradiation damage. The desorption of the adsorbed toxin in water ranged from 37.5% to 56.4% and from 27.4% to 41.8% in a carbonate buffer. The desorption percentage also decreased with increasing rectorite：toxin ratio.从书籍的右页仪式上的杆菌 thuringiensis 紧张 WG-001 的毒素的吸附和解吸附作用在不同毒素或书籍的右页仪式集中被学习， pH 和温度。吸附的毒素的杀虫活性被决定致死浓度杀死 Heliothis 有佩带徽章权利的人的 50% 幼虫评估一(LC50 ) 。在钠碳酸盐的书籍的右页仪式上的毒素的吸附缓冲(pH 9 ) 在 0.5 1.0 h 和毒素的吸附等温线以内的到达平衡跟随了兰米尔方程(R2 > 0.99 ) 。在从 9 ～ 11 的 pH 范围(碳酸盐缓冲区) ，吸附的毒素与增加 pH 减少了。吸附数量与增加 rectorite:toxin 比率减少了。吸附没被在 10 和 50 ° C 之间的温度显著地影响。X 光检查衍射分析由毒素显示了书籍的右页仪式的置闰的出现。红外线的吸收光谱证明毒素的绑定没改变它的结构。吸附的毒素的 LC50 价值是比免费毒素的那些小的。书籍的右页仪式保护了毒素免受紫外线照射损坏的伤害。水里的吸附的毒素的解吸附作用在一个碳酸盐缓冲区从 37.5% ～ 56.4% 并且从 27.4% ～ 41.8%。解吸附作用百分比也与增加 rectorite:toxin 比率减少了。

关 键 词：Bacillus thuringiensis insecticidul uctivity RECTORITE toxin udsorption und desorption 

分 类 号：X53[环境科学与工程—环境工程]