Metabolic engineering of Escherichia coli for direct production of vitamin C from D-glucose

• Published in: Biotechnology for biofuels Vol. 15; no. 1; pp. 86 - 13
• Main Authors: Tian, Yong-Sheng, Deng, Yong-Dong, Zhang, Wen-Hui, Yu-Wang, Xu, Jing, Gao, Jian-Jie, Bo-Wang, Fu, Xiao-Yan, Han, Hong-Juan, Li, Zhen-Jun, Wang, Li-Juan, Peng, Ri-He, Yao, Quan-Hong
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 22.08.2022; BioMed Central; BMC
• Subjects: Ascorbic acid; Biosynthesis; Carbohydrates; Care and treatment; D-Glucose; D-Sorbitol; E coli; Engineering; Enzymes; Escherichia coli; Feasibility studies; Fermentation; Flasks; Gene expression; Genes; Glucose; Metabolic engineering; Metabolism; Metabolites; One-step fermentation; Shaking; Sorbitol; Streaming; Synthesis pathway; Vitamin C; China; One-step fermentation; Synthesis pathway; D-Glucose; Vitamin C
• ISSN: 2731-3654; 2731-3654; 1754-6834
• DOI: 10.1186/s13068-022-02184-0

Production of vitamin C has been traditionally based on the Reichstein process and the two-step process. However, the two processes share a common disadvantage: vitamin C cannot be directly synthesized from D-glucose. Therefore, significant effort has been made to develop a one-step vitamin C fermentation process. While, 2-KLG, not vitamin C, is synthesized from nearly all current one-step fermentation processes. Vitamin C is naturally synthesized from glucose in Arabidopsis thaliana via a ten-step reaction pathway that is encoded by ten genes. The main objective of this study was to directly produce vitamin C from D-glucose in Escherichia coli by expression of the genes from the A. thaliana vitamin C biosynthetic pathway. Therefore, the ten genes of whole vitamin C synthesis pathway of A. thaliana were chemically synthesized, and an engineered strain harboring these genes was constructed in this study. The direct production of vitamin C from D-glucose based on one-step fermentation was achieved using this engineered strain and at least 1.53 mg/L vitamin C was produced in shaking flasks. The study demonstrates the feasibility of one-step fermentation for the production of vitamin C from D-glucose. Importantly, the one-step process has significant advantages compared with the currently used fermentation process: it can save multiple physical and chemical steps needed to convert D-glucose to D-sorbitol; it also does not involve the associated down-streaming steps required to convert 2-KLG into vitamin C.