Li X, Ricke S C
Poultry Science Department, Texas A&M University, Kleberg Center, Room 101, College Station, TX 77843-2472, USA.
Bioresour Technol. 2003 Sep;89(3):249-53. doi: 10.1016/s0960-8524(03)00072-5.
The objective of this study was to investigate the effect of a lysine biosynthesis insertion mutation on the growth response and phenotype of Escherichia coli. The lysA gene encodes the last enzyme in the lysine biosynthetic pathway in most bacteria. This E. coli insertion mutant exhibited altered growth physiology and phenotype of the recipient E. coli. The constructed mutant could grow in the absence of lysine supplementation although the extent of growth after 7 h incubation in the presence of most lysine concentration was significantly (p<0.05) decreased compared to that observed with the parent E. coli strain. The mutant was also less able to utilize carbon and nitrogen substrates than the parent E. coli strain as determined by using phenotype arrays. These results suggest that the carbon and nitrogen phenotype profiles of E. coli when measured on phenotype arrays are altered after targeted insertion mutagenesis in the lysA gene. Creation of altered phenotypes may have potential for pharmaceutical and biotechnological applications of lysine E. coli metabolism.
本研究的目的是调查赖氨酸生物合成插入突变对大肠杆菌生长反应和表型的影响。lysA基因编码大多数细菌中赖氨酸生物合成途径的最后一种酶。这种大肠杆菌插入突变体表现出受体大肠杆菌生长生理学和表型的改变。构建的突变体在不补充赖氨酸的情况下能够生长，尽管在大多数赖氨酸浓度下培养7小时后的生长程度与亲本大肠杆菌菌株相比显著（p<0.05）降低。通过使用表型阵列确定，该突变体利用碳和氮底物的能力也低于亲本大肠杆菌菌株。这些结果表明，在lysA基因中进行靶向插入诱变后，通过表型阵列测量的大肠杆菌碳和氮表型谱会发生改变。改变表型的产生可能对赖氨酸大肠杆菌代谢的制药和生物技术应用具有潜在意义。
