过表达carAB和pyrBI对大肠杆菌发酵胞苷的影响  

Effects of carAB and pyrBI Overexpression on Cytidine Fermentation in Escherichia coli

作　　者：吴晓娇[1] 孙家凯[1] 霍文婷[1] 谢希贤[1] 徐庆阳[1] 陈宁[1] 

机构地区：[1]天津科技大学生物工程学院工业发酵微生物教育部及天津市重点实验室,天津300457

出　　处：《中国生物工程杂志》2012年第2期39-44,共6页China Biotechnology

摘　　要：为了考察氨甲酰磷酸合成酶和天冬氨酸氨甲酰转移酶对大肠杆菌发酵生产胞苷的影响,以E.coli A39(△cdd)基因组为模板克隆carAB和pyrBI并与载体pSTV28连接构建出重组质粒pSTV28-carAB和pSTV28-pyrBI,将这两个重组质粒分别转入出发菌株A39(△cdd)后,通过摇瓶发酵研究重组质粒对菌体的生长、胞苷和尿苷产量及副产物乙酸积累的影响。结果显示,工程菌E.coli A39-AB和A39-BI的胞苷产量分别为583.5 mg/L、408.4 mg/L,与出发菌株相比,分别提高了85.3%、29.7%。这说明过表达操纵子基因carAB和pyrBI均可促进胞苷的积累。To study the effects of carbamoyl phosphate synthetase and aspartate carbamoyl transferase on cytidine fermentation of E. coli, carAB and pyrBI were amplified by PCR from E. coli A39 （ A cdd） chromosome and ligated into the pSTV28 vector. Then the recombinant plasmids pSTV28-carAB and pSTV28-pyrBI were transformed into E. coli A39 （Acdd）. And the effects of pSTV28-carAB and pSTV28-pyrBl on cell growth, eytidine and uridine production and accumulation of acetic acid were studied by fermentation experiments. The results suggested that cytidine productions of E. coli A39-AB and A39-BI were 583.5 mg/L and 408.4 mg/L, which were increased by 85.3% and 29.7% compared with A39 （Acdd）. It shows that Overexpressing carAB and pyrBI operon can promote the accumulation of cytidine.

关 键 词：carAB pyrBI胞苷发酵过表达 

分 类 号：Q786[生物学—分子生物学]