除草剂乙草胺的大量使用会污染农田土壤，并对动植物、人类和生态环境造成严重的安全隐患。乙草胺在土壤中的降解与土壤微生物密切相关，探索微生物在土壤乙草胺消除作用对于污染土壤的微生物修复具有重要意义。Bacillus sp. ATC-3是本项目组从环境中自行分离的乙草胺降解菌株，在以乙草胺为唯一碳源的基础盐培养基中37℃培养6天可以将100 mg•L-1 的乙草胺降解85%以上。为探索该菌株降解乙草胺的过程，本项目以ATC-3菌株为研究对象，分析其对不同相关底物的利用情况，并通过气相色谱-质谱联用等技术研究降解过程中的各种中间产物，解析菌株降解乙草胺的代谢途径；利用鸟枪法克隆乙草胺降解基因，验证其功能，并通过硫酸铵分级沉淀、阴离子交换和葡聚糖凝胶层析纯化其降解酶，研究其酶学特性。本项目拟在代谢途径以及基因和酶水平上阐明ATC-3菌株降解乙草胺的分子机制，为乙草胺污染的微生物修复提供理论依据。

The widely use of the herbicide acetochlor could polluted farmland soil，caused serious security risks to animals, plants, human and ecological environment. The dynamic process of residual acetochlor in soil was closely related to the soil microorganisms, so it’s important to research the role of microorganisms in the bioremediation of soil acetochlor residue elimination. In previous research, a acetochlor-degrading strain named ATC-3 was isolated from contaminated soil. When acetochlor was provided as the sole carbon source, the degradation efficiency in liquid medium was more than 85% after 6 days of inoculation with strain ATC-3. In order to find out the process of acetochlor degradation, the ATC-3 strain was used as the object to analyze the utilization of different substrates, study . The stydy of degrading- metabolite will be carried out by GC-MS to analyze the metabolic pathway of acetochlor degradation by strain ATC-3. We also want to obtain the degrading- genes by shotgun and verify its function. The degrading-enzymes will be purified by ammonium sulfate fractional precipitation, anion exchange and Sephadex gel chromatography,and then the enzymatic properties will be analyzed. Through the project, we could understand the molecular mechanism of acetochlor -degradation, which would provide new resources and ideas for the bioremediation of acetochlor contaminated soil.