文献类型：期刊文献

英文题名：Optimization of L-ornithine production in recombinant Corynebacterium glutamicum S9114 by cg3035 overexpression and manipulating the central metabolic pathway

作者：Zhang, Bin[1];Yu, Miao[1];Wei, Wen-Ping[1];Ye, Bang-Ce[1,2]

机构：[1]East China Univ Sci & Technol, State Key Lab Bioreactor Engn, Lab Biosyst & Microanal, Shanghai 200237, Peoples R China;[2]Zhejiang Univ Technol, Coll Pharmaceut Sci, Collaborat Innovat Ctr Yangtze River Delta Reg Ph, Hangzhou 310014, Zhejiang, Peoples R China

年份：2018

卷号：17

外文期刊名：MICROBIAL CELL FACTORIES

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000435420500002)】；

基金：This work was supported by grants from the National Natural Science Foundation of China (31730004 and 21575089).

语种：英文

外文关键词：Corynebacterium glutamicum; L-Ornithine; Metabolic engineering

摘要：Background: L-Ornithine is an important amino acid with broad applications in pharmaceutical and food industries. Despite lagging L-ornithine productivity and cost reduction, microbial fermentation is a promising route for sustainable L-ornithine production and thus development of robust microbial strains with high stability and productivity is essential. Results: Previously, we systematically developed a new strain, SO1 originate from Corynebacterium glutamicum S9114, for L-ornithine production. In this work, overexpression of cg3035 encoding N-acetylglutamate synthase (NAGS) using a plasmid or by inserting a strong P-tac promoter into the chromosome was found to increase L-ornithine production in the engineered C. glutamicum SO1. The genome-based cg3035 modulated strain was further engineered by attenuating the expression of pta and cat, inserting a strong P-eftu promoter in the upstream region of glycolytic enzymes such as pfkA, gap, and pyk, and redirecting carbon flux to the pentose phosphate pathway. The final strain with all the exploratory metabolic engineering manipulations produced 32.3 g/L of L-ornithine, a yield of 0.395 g ornithine per g glucose, which was 35.7% higher than that produced by the original strain (23.8 g/L). Conclusion: These results clearly demonstrated that enhancing the expression of NAGS promoted L-ornithine production and provide a promising alternative systematic blueprint for developing L-ornithine-producing C. glutamicum strains.