摘要
为了构建生长快、培养简便的高产衣康酸工程菌,在表达编码顺乌头酸脱羧酶的cad基因基础上,过表达编码柠檬酸合酶的glt基因,所得重组菌株摇瓶发酵24h产生104mg/L的衣康酸。通过进一步表达ACS基因构建乙酸回补途径,衣康酸含量达到128mg/L,提高17%。外源添加柠檬酸钠和顺乌头酸对衣康酸的合成有明显的促进作用。共表达cad、glt和ACS的工程菌在IPTG诱导后0h加入12g/L柠檬酸钠,18℃摇瓶培养24h,衣康酸的产量达到317mg/L,柠檬酸盐的利用率达到66%,发酵液中仅有少量的乙酸(0.579g/L)积累。研究结果表明:通过衣康酸合成代谢途径的强化和衣康酸前体的适当供给可以有效提高大肠杆菌生产衣康酸的能力。
Itaconic acid is an important chemical widely used in the fields of plastics,resins,coatings and other materials.To construct a engineered bacteria with fastgrowth,easycultivation and high-yield itaconic acid,the recombinant overexpressing cad(encoding cis-aconitate decarboxylase)and glt(encoding citrate synthase)produced 104 mg/L itaconic acid in flask culture for 24 h.Furtherly,the construction of acetic acid replenishment pathway by expressing ACS increased the content of itaconate by 17% to 128 mg/L.Exogenous addition of sodium citrate and aconitic acid could obviously promote the synthesis of itaconate.After 12 g/L sodium citrate was added at 0 h of IPTG induction,the recombinant co-expressing cad,glt,and ACS was cultured in a shake flask at 18℃ for 24 h.The titer of itaconic acid and the utilization of citrate reached 317 mg/L and 66%,respectively,and only a small amount of acetic acid(0.579 g/L)accumulated in the fermentation broth.These results suggested that the production of itaconic acid by E.coli can be effectively enhanced via strengthening the biosynthesis pathway of itaconic acid and proper supply of itaconic acid precursors.
作者
甘晟勋
萧琦
刘欢
刘军锋
邓利
王芳
GAN Shengxun;XIAO Qi;LIU Huan;LIU Junfeng;DENG Li;WANG Fang(College of Life Science and Teolinology,Beijing Key Laboratory of Bioprocess,Beijing University of Chemical Technology,Beijing 100029,China;Amoy-BUCT Industrial Bio-technovation Institute,Xiamen 361000,China)
出处
《重庆理工大学学报（自然科学）》
CAS
北大核心
2020年第11期207-214,共8页
Journal of Chongqing University of Technology：Natural Science
基金
国家重点研发计划项目(2017YFB0306904)。
关键词
衣康酸
大肠杆菌
发酵
乙酸回补
柠檬酸钠
itaconate
E.coli
fermentation
acetic acid replenishment
sodium citrat
