中文摘要：

旨在从小花棘豆（Oxytropis glabra DC）生长环境中分离可降解其主要毒性成分苦马豆素（Swainsonine,SW）的微生物。通过富集驯化培养,以SW为唯一碳源,从埋置小花棘豆的土壤中分离得到1株SW降解菌。形态学观察表明该降解菌为革兰氏阴性短小杆菌,无荚膜,无鞭毛;生理生化检测发现该降解菌氧化酶阳性,不产吲哚,不水解淀粉;16SrDNA序列比对分析表明该降解菌属于假单胞菌科假单胞菌属微生物,序列比对发现与恶臭假单胞菌（Pseudomonas putida）同源性最高。在SW无机盐液体培养基中培养24h,菌株对100mg/L SW的降解率为30.12%,延长培养时间不能提高其降解SW的能力,但可在高质量浓度SW（1 000mg/L）的处理下生长;该降解菌在无SW刺激的条件下转接50代,对100mg/L SW的降解率无明显影响。

英文摘要：

The aim of this study is to investigate the major toxin swainsonine（SW） degrading bacterial strain isolated from soil where Oxytropis glabra DC grows. Using traditional enrichment procedure, this bacterial strain was screened when SW was used as a sole carbon source, and this strain of SW-degrading bacteria was isolated from soil where O. glabra DC embed. Morphological investigation showed that bacterial strain was Gram negative, bacillus pumilis, capsule-free and flagella-free. Physiological and biochemical results showed that bacterial strain was positive for oxidase, and negative for indoltheticum and amylolysis. 16S rDNA sequencing and blasting indicated that bacterial strain was taxonomically classified as Pseudomonas. And the homology exhibited highest compared with Pseudomonas putida. Its degradation rate reached to 30.12% under the circumstance of incubation on a shaker at 200 r/min and temperature at 37 ℃ within 24 hours when the concentration of SW was 100 mg/L in inorganic salt liquid medium, the capability of degrading SW could not be improved by extending cultivation time, while it could tolerate high concentration SW up to 1 000 mg/L, this strain was characteristic of degrading 100 mg/L SW after re-inoculating 50 times without stimulus of SW, Its degradation rate had no significant change, one bacterial stain was found resist to SW in this test, this bacterial stain couldbe made use for detoxification and utilization in O. glabra DC.