红假单胞菌立体选择性降解菊酯类农药机理及降解酯酶基因克隆

项目名称： 红假单胞菌立体选择性降解菊酯类农药机理及降解酯酶基因克隆

项目编号： No.31272067

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 农业科学

项目作者： 刘勇

作者单位： 湖南省农业科学院

项目金额： 75万元

中文摘要： 菊酯类农药分子结构中含有1-3个手性中心，有2个至多个异构体，而其杀虫活性成分只存在于1个或少数几个异构体。目前使用的菊酯类农药绝大多数是外消旋体，大量无活性的菊酯类农药异构体投入到环境中，给生态环境、人类自身健康带来严重威胁。因此，研究减少菊酯类农药无活性异构体的投入方法，既能减轻对生态环境的危害，又能增加防治效果、降低生产成本。微生物降解是生态环境中清除农药残留的一种重要途径，且微生物对手性污染物具有立体选择性降解作用。因此，本项目在前期研究红假单胞菌降解菊酯类农药残留物的基础上，研究红假单胞菌立体选择性降解菊酯类农药特性与机理，克隆降解酯酶基因、并构建筛选降解不同异构体的突变子，分析突变子酯酶三维构型，推导降解酯酶基因预测蛋白的构型与菊酯类农药分子构型之间的对应关系。本研究为利用立体选择性降解酶生产富含活性异构体的高效菊酯类农药提供理论依据。

中文关键词： 菊酯类农药；沼泽红假单胞菌；降解酯酶基因；分子构型；立体选择性

英文摘要： There are 1-3 chiral carbon atom(s) in molecular structure of pyrethroids, and correspondingly, 2 n isomers are concurrence in pyrethriods, but the insecticidal activity is only existing in one or few isomer(s). Lots of no insecticidal activity isomer(s) pour into entironment because of using of racemic pyrethroids in agricultural production process, resulted to severe threatening to entironment. So it is very important to uncover how to reduce the no insecticidal activity of isomer(s) of pyrethroids, for alleviating damage to entironment and human besing self and raising the profit of agricultural production. One of very important approach of cleaning pesiticides in entironment is microbial degradation, and is also enantioselective to chiral pesicides. This research project aimed to clarify enantioselective degradation of main pyrethroid by Rhodopseudomonas sp. PSB07-21, which screened in our former studies. In addition, the trails of cloning of the degradation enzyme gene and 3-D structure analysis of enzyme will perform, and then, muton(s) of this gene with function of degrading different isomer(s) of pyrethroids will construct by direct evolution strategy. The congruent relationship between 3-D structure of degradaion enzyme and enantioselective degradation should be deduced. The conclusions of this research

英文关键词： Synthetic pyrethroids；Rhodopseudomonas palustris；degrading esterase genes；molecular structure；stereo-selection