摘要
微生物还原亚硒酸盐的动力学研究具有重要的现实意义,可以为Se(IV)污染场地的微生物修复设计提供理论依据。本文研究了兼性厌氧菌Bacillus sp.SeRB-2对亚硒酸钠的还原动力学。通过指数方程模型、对数方程模型和米氏方程模型的分析可知,Se(IV)的细菌还原符合一级反应动力学,还原反应主要集中在对数期和稳定生长前期,米氏方程模型能更好的反映细菌对亚硒酸盐的还原过程。通过对不同Se(IV)浓度下的米氏常数(Km)和最大反应速率(Vmax)的分析发现,当Se(IV)浓度较低时,Km值较小,Vmax值较大,这表明Se(IV)浓度越低,还原亚硒酸盐的酶与Se(IV)的结合能力越强,此时细菌对亚硒酸盐的还原速率越大、还原效率也越高。在本研究中,当Se(IV)浓度为1mmol/L时,其还原效率最高可达90%,能够有效去除或降低Se(IV)污染,说明该菌在Se(IV)污染场地的生物修复上具有应用潜力。
It is significant to study the bioreduction kinetics of selenite, which may provide a theoretical basis for bioremediation design in the contaminated sites. The kinetics of Se（IV） reduction by facultative anaerobic strain Bacillus sp. SeRB-2 was studied using the index equation model, logarithm equation model and Michaelis-Menten equation model. It is shown that Se （IV） bioreduction fits a first-order reaction, and reacts mainly in the logarithmic phase and early stationary phase. The Michae- lis-Menten equation model better reflects the reduction process compared with both index and logarithm equation models. The kinetic parameters Km and Vmax acquired were relevant to Se（IV） concentrations, i. e. , the lower the Se（IV） concentrations, the smaller the Km value and the hither Vmax will be. It is indicated that the binding ability between Se-（IV）-reducing enzyme and selenite is stronger, the reducing rate is larger and the reducing efficiency is higher, in a lower Se（IV） medium. In addi- tion, the reduction efficiency is up to 90%, when Se （IV） concentrations are about lmmol/L, which illustrates that Se（IV） contamination can be effectively reduced or removed by strain SeRB-2. This strain may be suitable for bioremediation in the Se （IV） contaminated sites.
出处
《地球与环境》
CAS
CSCD
北大核心
2014年第1期47-54,共8页
Earth and Environment
基金
国家自然科学基金创新群体项目(41021062)
国家自然科学基金项目(41173030)
中国科学院知识创新工程重要方向项目(KZCX2-EW-102)
关键词
细菌
还原
亚硒酸盐
动力学
参数
bacterium
reduction
selenite
kinetic
parameter
