摘要
采用河南信阳产钠型蒙脱石为实验材料,研究了苏云金芽胞杆菌(Bt)工程菌株WG-001原毒素蛋白(130kDa)在粒径为0～0.2μm和0～2μm的蒙脱石上的吸附特性。结果表明,蒙脱石在碳酸盐缓冲体系(pH9)对Bt原毒素蛋白的等温吸附曲线符合Langmuir方程(r2>0.99),当原毒素与蒙脱石的质量比例相同时,蒙脱石的平均粒径越小,单位质量吸附量越高。在磷酸盐体系(pH6～8)pH7时单位质量吸附量最大,在碳酸盐体系(pH9～11)单位质量吸附量随pH的增加而下降。Bt原毒素在蒙脱石上的吸附0.5～1.0h就能达到平衡。随着蒙脱石质量比例的增加,蒙脱石对原毒素的单位质量吸附量减小,但吸附百分率增加。在10℃～50℃范围内,温度对单位质量吸附量影响不大。透射电镜分析表明,吸附原毒素前后蒙脱石的粒径没有明显改变。XRD分析证实,吸附原毒素后蒙脱石层间距没有发生变化。
The adsorption characteristics of the protoxin （130 kDa） of Bacillus thuringiensis strain WG-001 on 0-0.2 μm and 0-2 μm particles of montmorillonite were studied. The adsorption isotherms of protoxin in sodium carbonate buffer （pH 9） followed Langmuir equation （r^2〉 0.99）, the finer the particle, the higher the adsorption at the same ratio of montmorillonite： protoxin. In phosphate buffer （pH6-8）, the maximum adsorption of protoxin on montmorillonite occurred at pH 7, while in carbonate buffer （pH 9-11）, the adsorption of protoxin decreased with increasing pH. The adsorption of protoxin on montmorillonite reached equilibrium within 0.5- 1 h. With the increase of the ratio of montmorillonite： protoxin, the adsorption amount decreased whereas the adsorption percent increased. The analysis of transmission electron microscopy （TEM） showed that no obvious changes for the granular diameter of dispersed montmorillonite before and after adsorption. The results of XRD analysis indicated that no significant enlargement of layer distance of montmorillonite was observed.
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2006年第4期992-996,共5页
Journal of Agro-Environment Science
基金
天津市自然科学基金资助项目(05YFJMJC05100)
关键词
苏云金芽胞杆菌
原毒素
蒙脱石
吸附
Bacillus thuringiensis
protoxin
montmorillonite
adsorption
