随着全球气候变暖和氮磷的排放，蓝藻水华在我国和世界仍然处于增加趋势，其最主要危害是产生并释放使人致癌的节球藻毒素(Nodularins,NODs)和微囊藻毒素(Microsystins,MCs)，因此对人们饮用水安全构成了严重威胁。NODs属于单环五肽结构稳定化合物，虽然世界上对MCs生物降解研究较多，但国内对NODs生物降解则基本处于研究空白。我们在发现鞘氨醇单胞菌USTB-05及粗酶具备高效生物降解NODs能力并观察到降解产物基础上，本申报项目拟将现代分子生物学技术和计算机分子模拟相结合，开展NODs降解基因的克隆，具备催化活性重组降解酶的表达与纯化、NODs降解产物结构识别和重组酶催化降解NODs 机理的分子模拟等一系列系统深入研究，全面揭示鞘氨醇单胞菌USTB-05生物降解NODs的途径与分子机理，不仅为丰富和发展NODs的生物降解理论做出贡献，而且为快速高效去除NODs奠定基础。

With the global warming and discharge of wastewater containing a huge amount of nitrogen and phosphorus, harmful cyanobacterial bloom is increasing all over the world, and its main harm is to produce and release the carcinogenic nodularins (NODs) and microsystins (MCs), which may threaten the safety of human drinking water. NODs belong to the stable monocyclic pentapeptides. Although many people study on the biodegradation of MCs in the world, almost no information is provided on the biodegradation of NODs in China. Base on the successful findings of NODs can be biodegraded by Sphingopyxis sp. USTB-05 and its crude enzymes, and the metabolite products of NODs are observed, combined the modern molecular biological technique with the computer molecular simulation, we will study on the cloning of biodegradation genes, and the expression and purification of recombinant biodegradation enzymes, and the identification of biodegradation products as well as the mechanism of molecular simulation in this applied project. The pathway and molecular mechanism for the biodegradation of NODs by Sphingopyxis sp. USTB-05 are firstly studied, which will provide our contribution on the enrichment and development of theory for the biodegradation of NODs and the application of genetic engineering bacteria in the removal of NODs from water body.