High-yield ectoine production in engineered Corynebacterium glutamicum by fine metabolic regulation via plug-in repressor library. (October 2022)

• Record Type: Journal Article
• Authors: Jiang, An; Song, Yunhai; You, Jia; Zhang, Xian; Xu, Meijuan; Rao, Zhiming
• Is Part Of: Bioresource technology. Volume 362(2022)
• Publication Date: 2022-10
• Subjects: Corynebacterium glutamicum -- Ectoine -- Metabolic engineering -- UTR Library designer -- Plug-in repressor library; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2022.127802
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Ectoine synthesis pathway of Pseudomonas stutzeri reconstruction in C. glutamicum. Plug-in repressor library with diverse expression levels achieved in C. glutamicum . The repressor library enabled precise flux control to improve ectoine production. A final titer of 45.52 g/L with a high yield of 0.25 g/g glucose. Abstract: Ectoine is a high-value protective and stabilizing agent with different applications in biopharmaceuticals, biotechnology, and fine chemicals. Here, efficient production of ectoine in Corynebacterium glutamicum was achieved by combination of metabolic engineering and plug-in repressor library strategy. First, the ectBAC cluster from Pseudomonas stutzeri was introduced into strain K02, and the titer of the obtained strain was 2.12 g/L. Metabolic engineering was then performed for further optimization, including removal of competing pathways ( pck and ldh knockout), deletion of glycolysis repressor ( sugR knockout), and enhancement of precursor supply (overexpression of Ecasd and CglysC S301Y ). Next, two repressor libraries were designed for targeted flux control to improve ectoine production. Finally, strain CB5L6 produced 45.52 g/L ectoine and had the highest yield in C. glutamicum . For the first time, plug-in repressor library was employed to engineer C. glutamicum for metabolites production, which will provide a guideline for the construction of microbial cell factories.