Spectral Studies of the Tozin of Bt Adsorbed by Minerals
The persistence of the toxin of Bacillus thuringiensis (Bt) may constitute risk to the soil ecosystem, and toxin structure in soils could affect their persistence, insecticidal activity, and decomposition. The structural changes of Bt toxin during adsorption and desorption on montmorillonite, kaolinite, goethite and silicon dioxide were investigated by infrared spectroscopy (IR) and fluorescence spectroscopy. A comparison between the iR spectra of native toxin and toxin-mineral complexes indicated no obvious structural changes appeared, and the C-N radicel played a key role on the adsorption of the toxin by minerals. Fluorescence spe ctroscopy showed that two fluorescence peaks of the Bt toxin were at 338 nm and 314.5 nm by the excitation at 282 nm, which attributed to tryptophan and tyrosine residues, respectively. The maximum fluorescence emission (λem, 338nm) of Bt toxin desorbed from kaolinite and montmorillonite were red-shifted 5 nm and 9.5 nm, respectively, while λem of Bt toxin desorbed from goethite and silicon dioxide did not shift obviously. This investigation may help evaluate the behavior and fate of Bt toxins in the soil ecosystem.
Adsorption Bt tozin Fluorescence spectroscopy Infrared spectroscopy Minerals
Qingling Fu Hongqing Hu Shouwen Chen Li Huang Qiaoyun Huang Tongmin Sa
Key Laboratory of Subtropical Agricultural Resources and Environment,Ministry of Agriculture,Huazhon Department of Agricultural Chemistry,College of Agriculture,Chungbuk National University,Cheongju,36
国际会议
杭州
英文
207-209
2009-10-10（万方平台首次上网日期，不代表论文的发表时间）