摘要
该研究以L-酪氨酸合成的两个关键基因aroG和tyrR为研究靶点,在大肠杆菌(Escherichia coli)TRP1中上调表达解除反馈抑制的基因aroG,强化莽草酸途径,同时敲除基因tyrR,解除TyrR蛋白对aroG、tyrB、aroF、tyrA、aroL、aroP、tyrP多个基因的转录抑制,构建高产L-酪氨酸的重组工程菌株,并以L-酪氨酸产量为评价指标,采用单因素及正交试验对重组工程菌株的发酵培养基进行优化。结果表明,获得一株高产L-酪氨酸的重组菌株TY03,L-酪氨酸产量为(17.4±0.15)g/L,是出发菌株大肠杆菌TRP1的86倍,其产L-酪氨酸的最优发酵培养基为:酵母粉8 g/L、MgSO_(4)·7H2O 4 g/L、FeSO_(4)·7H2O 40 mg/L、MnSO_(4)·H2O 40 mg/L、VB15 mg/L、VH 8 mg/L、(NH_(4))_(2)SO_(4)5 g/L、KH2PO_(4)3 g/L,在此条件下,L-酪氨酸产量为(20.9±0.19)g/L,比优化前提高了20%。该研究优化重组菌株TY03的培养基组成,同时对于大肠杆菌高效积累L-酪氨酸的定向改造提供了一种新思路。
Using the two key genes aroG and tyrR for L-tyrosine synthesis as research targets,the remove feedback inhibition gene aroG was up-regulate expressed,the shikimic acid pathway was strengthened,gene tyrR was knocked out at the same time,the transcriptional inhibition of TyrR protein on aroG,tyrB,aroF,tyrA,aroL,aroP,and tyrP genes was removed,and the high-yield L-tyrosine recombinant engineered strain was constructed.Using L-tyrosine yield as evaluation index,the fermentation medium of recombinant engineered strain was optimized by single factor and orthogonal experiments.The results showed that a recombinant strain TY03 with high-yield L-tyrosine was obtained,and the L-tyrosine yield was(17.4±0.15)g/L,which was 86 times that of the starting strain Escherichia coli TRP1.The optimal fermentation medium compositions for L-tyrosine production were as follows:yeast powder 8 g/L,MgSO_(4)·7H_(2)O 4 g/L,FeSO_(4)·7H_(2)O 40 mg/L,MnSO_(4)·H2O 40 mg/L,VB15 mg/L,VH 8 mg/L,(NH_(4))2SO_(4)5 g/L,and KH2PO_(4)3 g/L.Under these conditions,L-tyrosine yield was(20.9±0.19)g/L,which increased 20%than before optimization.The medium compositions of reco-mbinant strain TY03 were optimized,and a new idea for the targeted modification of L-tyrosine accumulation in E.coli.
作者
杜丽红
吕思琪
战俊杰
马志鹏
马丽媛
马雪
范恒军
孟天星
DU Lihong;LV Siqi;ZHAN Junjie;MA Zhipeng;MA Liyuan;MA Xue;FAN Hengjun;MENG Tianxing(College of Food and Pharmaceutical Engineering,Suihua University,Suihua 152000,China;Xiangyu Jingu Biochemical Technology Co.,Ltd.,Suihua 152000,China)
出处
《中国酿造》
CAS
北大核心
2023年第11期202-208,共7页
China Brewing
基金
黑龙江省教育厅基本科研业务费项目(YWK10236210232)
黑龙江省大学生创新创业训练计划项目(S202210236004)
黑龙江省自然科学基金(JJ2022LH1055)
黑龙江省青年科技人才托举工程项目(2022QNTJ08)。
关键词
大肠杆菌
L-酪氨酸
代谢工程
发酵培养基
正交试验
Escherichia coli
L-tyrosine
metabolic engineering
fermentation medium
orthogonal experiment
作者简介
杜丽红(1991-),女,讲师,博士,研究方向为代谢控制发酵。
