抗反馈抑制的天冬氨酸激酶基因在钝齿棒杆菌中的表达  

Expression of feedback-resistant aspartate kinase gene in Corynebacterium crenatum

作　　者：赵智[1] 刘阳剑[1] 王宇[1] 张英姿[1] 丁久元[1] 曹芹[1] 郝宁[1] 

机构地区：[1]中国科学院微生物研究所微生物生物技术中心,北京,100080

出　　处：《微生物学报》2005年第4期530-533,共4页Acta Microbiologica Sinica

摘　　要：将来自钝齿棒杆菌(Corynebacteriumcrenatum)CD945具有AEC抗性的天冬氨酸激酶(AKfbr)基因克隆到穿梭载体pJC1上,构建重组质粒pLY153。用电击法将质粒pLY153转化到野生型菌株C.crenatumAS1.542及其突变株C.crenatumCD945中。携带AKfbr基因的C.crenatumAS1.542菌株能抗浓度皆为12mgmL的AEC和苏氨酸。AKfbr基因在C.crenatumCD945中得到表达,天冬氨酸激酶活性提高4倍。摇瓶发酵实验结果表明,重组菌在对数前期和中期生长正常,不受抑制;与对照菌相比,赖氨酸终产量提高22%,赖氨酸生产率提高23%。The AEC-resistant aspartate kinase gene from C. crenatum CD945 was cloned into vector pJC1. Its expression was investigated both in the wild type C. crenatum AS1.542 and its mutant C. crenatum CD945. The result showed that C. crenatum AS1.542 harboring AK fbr gene could grow on the defined medium with the co-existence of 12mg/mL both of AEC and L-threonine respectively. Overexpression of AK fbr gene in C. crenatum CD945 results in a 4-fold increase of specific enzyme activity than the parental strain. The amplification of the activity of aspartate kinase yields 22% increase of L-lysine production and 23% increase of L-lysine productivity without affecting the growth rate.

关 键 词：钝齿棒杆菌 天冬氨酸激酶 赖氨酸 

分 类 号：Q786[生物学—分子生物学]