抗氧化酶过表达对趋磁螺菌MSR-1耐氧性的影响  

Effects of Antioxidant Enzyme Over-expression on Oxygen Tolerance of Magnetosirillum gryphiswaldense MSR-1

作　　者：刘聪[1] 李颖[1] 李季伦[1] 姜伟[1] 田杰生[1] 

机构地区：[1]中国农业大学生物学院农业生物技术国家重点实验室,北京100193

出　　处：《生物技术通报》2010年第10期215-220,230,共7页Biotechnology Bulletin

基　　金：国家自然科学基金面上项目(30970041)

摘　　要：在格瑞斯瓦尔德磁螺菌(Magnetospirillum gryphiswa ldense)MSR-1中分别过量表达3种抗氧化酶Fe-超氧化物歧化酶、谷胱甘肽过氧化物酶和过氧化氢酶HPII,并分析过量表达这3种酶对趋磁螺菌MSR-1耐氧性的影响。通过PCR分别扩增大肠杆菌DH5α的Fe-超氧化物歧化酶(sodB)、谷胱甘肽过氧化物酶(btuE)、过氧化氢酶HPⅡ(katE)基因序列,将前两个片段分别连接到广宿主质粒pBBR1MCS-2上,后一个片段连接到广宿主质粒pBBR1MCS-5上,构建成表达质粒pBBR1MCS-sodB,pBBR1MCS-btuE和pBBR1MCS-katE,将3个质粒通过双亲接合转移的方法分别转入趋磁螺菌MSR-1。3种抗氧化酶过表达对趋磁螺菌MSR-1耐氧性影响的试验结果为过量表达Fe-超氧化物歧化酶对菌体生长影响不明显;过量表达谷胱甘肽过氧化物酶、过氧化氢酶HPII使趋磁螺菌MSR-1致死。上述试验结果表明抗氧化酶系在菌体耐氧过程中的全局协调调控的重要性。In this study, genes of Fe-superoxide dismutase （ sodB）, glutathione-peroxidase （btuE） and catalase HPII （katE） were over-expressed in the MagnetospiriUum gryphiswaldense MSR-1, respectively. The effects of these three enzymes over-expression on the oxygen tolerance of MSR-I were analyzed, sodB, btuE and katE gene were amplified by PCR from E. coli DHSα. sodB and butE gene were connected with pBBRIMCS-2, and katE gene was connected with pBBR1MCS-5 to construct the expression plasmid pB- BR1MCS-sodB, pBBR1MCS-btuE and pBBR1MCS-katE, and then, these three expression plasmids were transferred to Magnetospiril- lure gryphiswaldense MSR-1 by conjugation, respectively. The results of tolerance of MSR-1 to oxygen showed that the over-expression of Fe-superoxide dismutase in MSR-1 had no obvious effects on cell growth, and the over-expression of glutathione-peroxidase and catalase HPII resulted in the death of MSR-1. This research revealed that the coordination regulation of antioxidant enzyme system in bacteria was important.

关 键 词：趋磁螺菌MSR—1 Fe-超氧化物歧化酶谷胱甘肽过氧化物酶过氧化氢酶HPII 

分 类 号：Q93[生物学—微生物学]