摘要
L-phe是重要的食品和医药中间体,用大肠杆菌发酵葡萄糖生成phe时,对葡糖糖转运起重要作用的磷酸烯醇丙酮酸糖磷酸转移酶系统(PTS)对phe产量合成有很大影响,在大肠杆菌PTS系统中,葡糖糖主要由ptsG基因编码的葡萄糖特异性转运蛋白酶ⅡCBGlc转运入细胞,通过基因敲除技术获取ptsG缺陷菌株,可以减少菌株对葡糖糖的摄取,减少乙酸的生成,利于菌株的高密度发酵和相关代谢中间物获得。利用Red同源重组技术将大肠杆菌染色体上的ptsG基因进行敲除,得到PTS缺陷菌株MD-ptsG-。该菌株在以葡萄糖为惟一碳源的培养基中摇瓶培养,菌密度为对照菌株的3.5倍,L-phe产量提高12%。
L-Phenylalanines are important food and pharmaceutical intermediates. The PTS system is very impor- tant to production of L- phenylalanine in culture of Escherichia coll. The ptsG gene for glucose-specific transporter enzyme II CBGle of the phosphotransferase system was knocked-out so as to reduce the accumulation of acetic acid in culture of Escherichia coli. Knockout of the ptsG gene in Escherichia coli was done by Red recombinant system. The ptsG gene was disrupted to construct the mutant called MD-ptsG-. The MD-ptsG- strain was incubated in the media using glucose as the sole carbon source and the culture density was 3.5 times of the control, L-phe yield increased by 12%.
出处
《氨基酸和生物资源》
CAS
2012年第2期5-8,共4页
Amino Acids & Biotic Resources
基金
国家发改委"2010年国家技术产业化微生物制造专项"
