疯草是我国西部草原上危害最为严重的毒草，其毒性成分为苦马豆素(SW)。家畜采食疯草后常引起群发性中毒死亡，但疯草具有与苜蓿相当的营养价值，为了能够充分利用疯草资源，本实验室前期对疯草毒素-SW生物降解菌进行了分离，得到了一株能够以SW为唯一碳源生长的节杆菌HW08。本项目在此基础上，首先对HW08菌的胞内、外粗酶进行活性检测,然后采用盐析、透析、层析等方法分离纯化降解SW的关键酶，并对其特性进行研究，通过蛋白质测序分析寻找降解酶基因；用气质联用、液质联用等方法检测关键酶降解SW后的产物，推导降解途径。本研究将进一步阐明HW08菌关键酶降解苦马豆素的机制，为生物防治动物疯草中毒病以及疯草的合理开发奠定基础。

Locoweed, one of the most hazardous plants, distributes the western grassland of China and produces toxin swainsonine(SW). In one hand, domestic animals often get deaths by poisoning because of foraging locoweeds; in the other hand, locoweeds have great nutritive value which is equivalent to purple medic to be explored.In previous study,we isolated a strain of Arthrobacter sp. HW08 which can grow with SW as sole carbon source. In this project,the activity of intra-cellular or ecto-cellular crude enzymes from HW08 will be determined first.Then the key SW-degrading enzymes will be purified using salting-out,dialysis and chromatography.The characteristics of key SW-degrading enzymes will be investigated further.The genes of SW-degrading enzymes will be determined by protein sequencing. Finally we will determine the metabolites after SW degrading and its metabolic pathway using gas chromatography mass spectrometry and liquid chromatography mass spectrometry. Clarification the mechanism of degrading SW by key enzymes in HW08 will be useful for preventing the poisoning of locoweeds and exploring the locoweeds.