Department of Pharmaceutical Engineering, College of Health Science, Sangji University, 660 Woosan-dong, Wonju-si, Gangwon-do, 220-702, Korea.
J Ind Microbiol Biotechnol. 2010 Nov;37(11):1131-6. doi: 10.1007/s10295-010-0760-3. Epub 2010 Jun 12.
We recently proposed a metabolic engineering strategy for L-ornithine production based on the hypothesis that an increased intracellular supply of N-acetylglutamate may further enhance L-ornithine production in a well-defined recombinant strain of Corynebacterium glutamicum. In this work, an argJ-deficient arginine auxotrophic mutant of C. glutamicum is suppressed by a different locus of C. glutamicum ATCC13032. Overexpression of the NCgl1469 open reading frame (ORF), exhibiting N-acetylglutamate synthase (NAGS) activity, was able to complement the C. glutamicum arginine-auxotrophic argJ strain and showed increased NAGS activity from 0.03 to 0.17 units mg(-1) protein. Additionally, overexpression of the NCgl1469 ORF resulted in a 39% increase in excreted L-ornithine. These results indicate that the intracellular supply of N-acetylglutamate is a rate-limiting step during L-ornithine production in C. glutamicum.
我们最近提出了一种基于假设的 L-鸟氨酸生产的代谢工程策略，即增加细胞内 N-乙酰谷氨酸的供应可能会进一步增强谷氨酸棒状杆菌中已定义的重组菌株的 L-鸟氨酸生产。在这项工作中，谷氨酸棒状杆菌的精氨酸缺陷型营养缺陷型突变体被谷氨酸棒状杆菌 ATCC13032 的不同基因座所抑制。N-乙酰谷氨酸合酶（NAGS）活性的 NCgl1469 开放阅读框（ORF）的过表达能够补充谷氨酸棒状杆菌精氨酸营养缺陷型 argJ 菌株，并使 NAGS 活性从 0.03 增加到 0.17 单位 mg(-1) 蛋白。此外，NCgl1469 ORF 的过表达导致分泌的 L-鸟氨酸增加了 39%。这些结果表明，在谷氨酸棒状杆菌中 L-鸟氨酸生产过程中，细胞内 N-乙酰谷氨酸的供应是限速步骤。
