过量表达钝齿棒杆菌柠檬酸合酶编码基因prpC2对L-精氨酸合成的影响  

Cloning,Expressing of the prpC2 Gene Encoding Citrate Synthase from Corynebacterium crenatum and Its Effect on L-arginine Synthesis

作　　者：房战 徐美娟[1] 饶志明[1] 满在伟[1] 许正宏 耿燕 陆茂林[3] 

机构地区：[1]江南大学工业生物技术教育部重点实验室,无锡214122 [2]江南大学药学院,无锡214122 [3]江苏省微生物研究所有限公司,无锡214063

出　　处：《中国生物工程杂志》2015年第3期49-55,共7页China Biotechnology

基　　金：国家"973"计划(2012CB725202);国家"863"计划(2012AA022102);国家自然科学青年基金(31300028);教育部重点研究项目(113033A);江苏省青年自然科学基金(BK20130137);中央高校基本科研业务费专项资金(JUSRP51306A)资助项目

摘　　要：钝齿棒杆菌(Corynebacterium crenatum)SYPA5-5是诱变选育的一株高产精氨酸菌株。柠檬酸合酶作为TCA途径的关键酶,对细胞胞内氨基酸代谢流调节有重要作用。在钝齿棒杆菌SYPA5-5中过量表达同源的柠檬酸合酶(citrate synthase)基因prp C2,研究其对精氨酸及副产物合成的影响。重组菌C.crenatum SYPA5-5/p DXW-10-prp C2胞内柠檬酸合酶比酶活提高了5.37倍,使L-精氨酸产量在5L发酵罐中达到44.7g/L,与对照相比提高了23.1%。同时,有机酸测定分析TCA循环的精氨酸前体柠檬酸及异柠檬酸的量有所提高,且赖氨酸合成前体草酰乙酸量减少,氨基酸测定分析L-精氨酸发酵中最主要的副产物L-赖氨酸浓度由原来的5.96g/L降到1.21g/L,降低了80%。Corynebacterium crenatum SYPA5-5 is an L-arginine high-producing industrial strain of mutation breeding. The role of citrate synthase in L-arginine biosynthesis was investigated by overexpressing the citrate synthase （prpC2） gene in C. crenatum SYPA5-5. The resultant 5.37-fold increase in intracellular citrate synthase activity was achieved in the prpC2-overexpressing strain C. crenatum SYPA5-5/pDXW-10-prpC2 . The recombinant strain enhanced the L-arginine yield to 44.7g/L by about 23.1% in 5L fermenter, as compared to the control, with affecting glucose depletion rate slightly. While the L-arginine yield increased in the prpC2-overexpressing strain, the L-lysine yield, the most primary by-product formation during L-arginine fermentation, decreased to 1.21g/L from the original concentration 5.96g/L, correlating with an increase in the tricarboxylic acid cycle （TCA） intermediates （citrate and isocitrate） and an increase in the activity of citrate synthase.

关 键 词：L-精氨酸 钝齿棒杆菌 柠檬酸合酶 发酵 

分 类 号：Q78[生物学—分子生物学]