新型水体重金属吸附及逃逸控制微生物的设计与构建

粗放的工业排放造成我国河流水体重金属污染严重。因水体流动快，扩散性强，对水体环境中重金属的清理已经成为亟待解决的重大环境问题。基于微生物的重金属吸附逐渐成为研究热点之一。但天然重金属吸附微生物的效率不高，需要改造提高活力；再者，被吸附的重金属仍存在于环境中，存在二次污染的风险，需要开发快速、成本低的回收手段；次者，要考虑工程菌株的生物安全性，需要开发防逃逸技术，实现其环境可控。本项目针对上述技术需求，开展高效重金属吸附元件、微生物富集回收元件及微生物逃逸控制元件的人工设计与优化等基础研究；利用各种诱导型启动子设计遗传回路（Genetic circuit），对吸附元件、富集元件、逃逸控制元件的表达进行调控，实现对微生物的吸附、富集和死亡行为的人工控制；构建高效、生物安全的重金属污染修复菌株，并进行工程菌株在模拟水体的应用评价。该研究可为微生物修复水体重金属污染技术提供理论基础。

The rivers have serious pollution with heavy metals due to long-term industrial emissions in China. Because of the high mobility of waterbody, the polluted rivers are posing significant threat to the environment. Among the water pollutants, the relatively low concentration of heavy metals are dangerous and difficult to clean by chemo-physical treatment. Recently, microbial absorption-based methods are becoming increasingly popular, but the absorption efficiency of natural microbes tends to be low and needs to be improved. Additionally, heavy metal ions absorbed by microbes in current reports are not really removed from the environment, which are at high risk of causing secondary pollution, thus fast and low-cost method are required to recover microbes with heavy metals. Moreover, the biosafety concern of engineered microbes requires technology to be developed to manage the environmental impact of such microbes. To meet these urgent requirements, this proposal plans to investigate the principles for the rational design of heavy metal absorption parts, microbe recovery parts and biosafety parts. Together with various inducible promoters, these parts can be incorporate into genetic circuits to control the engineered microbes’ behaviors such as absorption, recovery and death. In the last, the constructed heavy-metal-cleaning microbes are planed to be put in modeling waterbody to evaluate the efficiency and biosafety as well as its impact on the indigenous microbial population. This project could provide the theoretical basis for microbial absorption-based bioremediation of water with heavy metal pollution.