浸矿微生物硫酸盐同化与重金属抗性耦合作用机制

Inner Mongolia is located in the western part of our country, which has rich mineral resources, but there are a large number of low-grade and smelter tailings that can not be effectively utilized. Bioleaching is the extraction of specific metals from their ores through the use of living organisms. This is much cleaner, low-cost, short processes than the traditional heap leaching using cyanide. Therefore，it is very important that we research sulfate assimilation and heavy metal resistance in bioleaching. It will reveal the micro-organisms ability to adapt to the molecular mechanism of this extreme environment, improve the efficiency of leaching, and expand its application areas. We will use Acidithiobacillus ferrooxidans as bacteria to develop this project. According to mark the element method of 35S, and other methods, we will suggest the mechanism of the sulfate transport and uptake using molecular cloning, expression and other methods about several key enzymes activity and transcriptional level difference. We will reveal the sulfate assimilation basic metabolic pathway and the sulfate assimilation pathway regulation mechanism using real-time PCR and other methods. We will suggest the relation between heavy metal resistance and the sulfate assimilation when using different microbiology grown at different concentration and different types of heavy metals. It is very important to improve the bioleaching efficiency.

内蒙古地处西部，矿产资源丰富，但存在大量的低品位及选冶尾矿，不能有效利用。生物冶金在低品位、复杂、难处理的硫化矿资源的开发利用上，具有低成本、短流程、污染小等优点。因此对浸矿微生物开展代谢及抗性机制的研究，对揭示微生物适应这种极端环境的分子机制，提高浸矿效率，拓展其应用领域，将具有非常重要的意义。本项目以嗜酸氧化亚铁硫杆菌为模式菌体，以标记元素35S等方法，研究硫酸盐的转运蛋白，揭示硫酸盐的吸收和转运分子机制；以分子克隆、表达等方法研究硫酸盐同化基本路径上的几个关键酶的酶活性质，转录水平差异，揭示硫酸盐同化的基本代谢路径；用不同调控物质作用菌体，以检测硫醇等化合物含量等方法，阐述硫酸盐同化代谢途径的调控机制；以荧光定量PCR等方法，研究浸矿微生物在不同的重金属耐受情况下，重金属抗性与硫酸盐同化的相互作用关系，为提高浸矿效率奠定基础。

内蒙古地处西部，矿产资源丰富，但存在大量的低品位及选冶尾矿，不能有效利用。生物冶金在低品位、复杂、难处理的硫化矿资源的开发利用上，具有低成本、短流程、污染小等优点。因此对浸矿微生物开展代谢及抗性机制的研究，对揭示微生物适应这种极端环境的分子机制，提高浸矿效率，拓展其应用领域，将具有非常重要的意义。本研究以嗜酸氧化亚铁硫杆菌为模式菌体，以共转录鉴定、分子克隆、表达等方法，研究了浸矿微生物硫酸盐同化基本路径上的几个关键酶的酶活性质，转录水平差异，揭示了浸矿微生物硫酸盐同化的基本代谢路径；探索了浸矿微生物重金属镉胁迫下重金属排出系统相关基因的表达情况，预测出其重金属抗性基因的作用模型；通过测定浸矿微生物硫酸盐同化途径和谷胱甘肽相关酶系的酶活、基因表达情况，阐述了浸矿微生物硫酸盐同化和重金属抗性耦合作用机制；以半胱氨酸、谷胱甘肽为调控物质作用菌体，研究了其对浸矿微生物硫酸盐同化代谢途径与重金属抗性的影响，为提高浸矿效率指导实际生产奠定基础。