重组核苷磷酸转移酶产生菌培养条件优化  

Optimization of culture condition for phosphotransferase production by recombinant Escherichia coli

作　　者：何宝龙[1] 孙丽慧[1] 郑裕国[1] 

机构地区：[1]浙江工业大学生环学院,浙江杭州310014

出　　处：《发酵科技通讯》2013年第3期1-4,共4页Bulletin of Fermentation Science and Technology

基　　金：国家自然科学基金青年项目(31101351)

摘　　要：5'-肌苷酸是一种重要的食品增鲜剂。核苷磷酸转移酶能够高选择性地使肌苷5'-位羟基磷酸酯化生成5'-肌苷酸,该反应不需要ATP,具有反应条件温和、反应速度快、位置特异性强、转化率高、环境友好等特点。以实验室前期构建的携带有来自Escherichia blattae磷酸转移酶(AP/PTase)编码基因的重组大肠杆菌E.coli BL21(DE3)/pET28b-AP/PT为菌株,研究了培养基成分对细胞生长和产酶的影响,确定了最优培养基为:甘油7.5 g/L,蛋白胨12.5 g/L,酵母粉10g/L,NaCl 10 g/L,ZnCl2 0.1 g/L,初始pH值7.0。在该条件下,核苷磷酸转移酶酶活达到143.8U/L,比优化前提高了1.0倍。利用该条件下培养获得的菌体为生物催化剂,反应1 h,5′-肌苷酸的摩尔收率达到83.3%,表明该核苷磷酸转移酶对肌苷具有良好的活性。Inosine-5′-monophosphate is one of the promising food additives.Phosphotransferase,possessed high regiospecificity of the nucleoside phosphorylating activity to the C-5＇-positon,is of high potential for the production of inosine-5′-monophosphate due to mild reaction conditions,high conversion rate and environment friendly.In this paper,recombinant E.coli BL21（DE3）/ pET28b-AP/PT which has expressed acid phosphatases was used,and the effects of culture conditions on cell growth and enzyme activity were investigated in shake flask.The optimal medium was as following（g/L）： glycerol 7.5,peptone 12.5,yeast extract 10.0,NaCl 10,ZnCl2 0.1,initial pH 7.0.Under the culture conditions,the enzyme activity reached 143.8 U/L.Using these microbial cells as catalyst,the yield of inosine-5′-monophosphate could be of 83.3% within 1 h,which showed the phosphotransferase possesses better activity.

关 键 词：重组大肠杆菌 核苷磷酸转移酶 发酵 条件优化 

分 类 号：TQ465.2[化学工程—制药化工]