厌氧微生物聚集体对苄嘧磺隆的降解与响应机制研究

Bensulfuron methyl (BSM), as a typical sulfonylureas herbicide, is the dominated herbicide in paddy fields. The residues of BSM are detected in agricultural drains, rivers and even groundwater. However, the degradation products have not been fully understood, especially the knowledge of degradation pathway under anaerobic conditions is little. In addition, most of the microorganisms are present in the form of microbial aggregates in anaerobic biological wastewater treatment systems and soils. However, report on the response mechanism of BSM to anaerobic microbial aggregates is still rather limited. Therefore, the anaerobic degradation pathway of BSM by anaerobic microbial aggregates, based on the metabolomics technology, will be studied in this proposal. In addition, the physicochemical characteristics of anaerobic microbial aggregates on BSM will be mentioned by combined use of chemical, spectroscopic and microscopic approaches. And the tools of molecular biology will also be used for analyzing community diversity and evolutionary changes of anaerobic microbial aggregates to discover the relationship among BSM, intermediate products and anaerobic microbial aggregates. The proposal will be beneficial for improvement of anaerobic biological treatment of BSM-producing wastewater, evaluation the environmental safety of BSM and bioremediation of BSM-contaminated soil.

磺酰脲类除草剂苄嘧磺隆是我国水稻田中的主导除草剂，虽然在农业排水渠、河流甚至地下水中都检测到苄嘧磺隆的残留，但其降解产物仍未形成系统的共性认识，尤其在厌氧条件下的降解途径尚未明确。在厌氧生物处理系统及土壤环境中，大多数微生物以微生物聚集体形式存在，但厌氧微生物聚集体对苄嘧磺隆为代表的磺酰脲类除草剂的响应机制还不清楚。因此，本课题基于代谢组学技术，探索厌氧微生物聚集体对苄嘧磺隆的降解途径；结合多种化学、光谱学分析方法，研究厌氧微生物聚集体表面物理化学特性对苄嘧磺隆的响应；利用分子生物学手段，解析厌氧微生物聚集体群落多样性及演替规律与苄嘧磺隆降解之间的联系；以期深入揭示苄嘧磺隆、中间产物、厌氧微生物聚集体之间的内在相互关系。本课题的研究对提高苄嘧磺隆生产废水厌氧生物降解效率，系统评估苄嘧磺隆环境安全性，及污染土壤的生物修复均具有一定的理论意义和实际价值。

磺酰脲类除草剂苄嘧磺隆是我国水稻田中的主导除草剂，其在厌氧条件下的降解途径尚未明确，并且厌氧微生物聚集体对苄嘧磺隆为代表的磺酰脲类除草剂的响应机制还不清楚。在国家自然科学基金委的支持下，本项目构建了表征厌氧微生物聚集体与苄嘧磺隆相互作用的新方法，并将上述方法扩宽到了厌氧微生物聚集体对纳米材料的响应，富集了苄嘧磺隆降解的稳定培养系，并对其培养条件进行了优化，解析了苄嘧磺隆在厌氧条件下的降解产物，完善了苄嘧磺隆降解途径，阐明了水环境中残留苄嘧磺隆对铜绿微囊藻的毒性效应，并解析了苄嘧磺隆对微生物的急性毒性作用机制，研究结果可为了解苄嘧磺隆等磺酰脲类除草剂在厌氧水处理过程中的环境行为、提高厌氧废水生物处理效率提供理论指导。研究成果主要以论文和专利的方式进行表达，在国外SCI源刊物上发表论文5篇；申请发明专利1项；培养研究生1名，在读博士生1名；项目负责人还入选闵恩泽能源化工奖-青年进步奖、中国科学院卢嘉锡青年人才奖等奖励。