Enhanced biosynthesis of 3, 4-dihydroxybutyric acid by engineered Escherichia coli in a dual-substrate system. (December 2017)

• Record Type: Journal Article
• Authors: Gao, Haijun; Gao, Yu; Dong, Runan
• Is Part Of: Bioresource technology. Volume 245:Part A(2017)
• Page Start: 794
• Page End: 800
• Publication Date: 2017-12
• Subjects: 3, 4-Dihydroxybutyric acid -- Synthetic pathway -- Dual-substrate system -- Combinational optimization; 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.2017.09.017
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: A four or five-step pathway was established in E. coli for 3, 4-DHBA production. A dual-substrate system contributed to highly efficient 3, 4-DHBA production. The elimination of multiple competitive pathways increased 3, 4-DHBA production. 3, 4-DHBA production was improved by regulation of NAD + availability. Abstract: 3, 4-Dihydroxybutyric acid (3, 4-DHBA), a versatile platform four carbon (C4) chemical, can be used as a precursor in the production of many commercially important chemicals. Here, a dual-substrate biosynthesis system was developed for 3, 4-DHBA production via a synthetic pathway established in an engineered Escherichia coli, and using xylose as a synthetic substrate and glucose as a cell growth substrate. The deletion of genes xylA, yjhH and yagE and others encoding for alcohol dehydrogenases in E. coli is essential for the production of 3, 4-DHBA. Blocking competing pathway by removing the gene yiaE encoding for a 2-keto-3-deoxy-D -xylonate reductase also facilitated carbon flow towards the synthesis of 3, 4-DHBA. Furthermore, regulation the availability of NAD + resulted in further improved 3, 4-DHBA production. The combinational optimization of the biosynthesis system led to a production of 0.38 g/L 3, 4-DHBA. This study provides an alternative 3, 4-DHBA biosynthesis approach with the possibility of utilizing hydrolysates of lignocellulosic biomass as substrates.