耐辐射奇球菌表面S层蛋白的生化功能及其在吸附转化重金属中的作用机制研究

重金属污染是世界性的环境污染问题并严重危害公共健康。基于微生物对重金属的吸附转化作用是一种环境友好的重金属生物处理技术，但是由于重金属对微生物的毒性作用，大多数微生物不适合用于高浓度重金属污染的处理，寻找并研究具有特殊抗逆性和可吸附转化重金属的微生物成为迫切需要。本项目研究的耐辐射奇球菌是一种能够忍受强烈氧化剂等极端逆境的非致病细菌，其细胞外被最外层是由特殊的蛋白结构单元构成的表面层（surface-layer, 简称S层）。本课题计划围绕耐辐射奇球菌S层蛋白的生化功能和特性，在前期研究的基础上，研究并揭示S层自组装特性与功能的关系，阐明S层在吸附转化重金属中的作用机制，旨在探讨其在治理重金属污染和回收有价值重金属材料方面的价值，研究结果不仅为阐明耐辐射奇球菌S层自组装功能和深入了解菌体超强抗性的分子机理提供新的见解，也为耐辐射奇球菌吸附和回收重金属的应用提供理论基础。

Heavy metal pollution constitutes a worldwide environmental pollution problem and leads to a serious hazard to public health. Bioremediation of heavy metals by microorganisms is an environmental friendly technology. Because of the toxicity of heavy metal on microorganisms, most of the microorganisms are not suitable for the treatment of pollution containing heavy metals at high concentrations. It is in need of screening and investigating the microorganisms with special resistance to stresses and bioremediation abilities on heavy metals. Deinococcus radiodurans is a nonpathogenic bacterium known for its resistance to extreme stresses including oxidants.The outermost layer of its cell envelope is the surface layer (S-layer) made of functional protein structure units. Our project will focus on the biochemical function and properties of S-layer protein in D. radiodurans. Relationship between the self-assembly characteristics and functions of S-layer will be investigated based on our previous study. The role and mechanism of self-assemblied S-layer in biosorption and transformation of heavy metals will be studied to evaluate its application in bioremediation and recovery of valuable heavy metals. The results will not only help to elucidate the self-assembly function of S-layer and the resistance mechanism of D. radiodurans to extreme stresses, but also provide fundament for the application of D.radiodurans in biosorption and recovery of heavy metals.