Introduction of an acetyl-CoA carboxylation bypass into Escherichia coli for enhanced free fatty acid production. (December 2017)

• Record Type: Journal Article
• Authors: Shin, Kwang Soo; Lee, Sung Kuk
• Is Part Of: Bioresource technology. Volume 245:Part B(2017)
• Page Start: 1627
• Page End: 1633
• Publication Date: 2017-12
• Subjects: Free fatty acid -- Acetyl-CoA carboxylation -- Methylmalonyl-CoA carboxyltransferase -- Bypass -- Escherichia coli; 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.2017.05.169
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: Methylmalonyl-CoA carboxyltransferase (MMC) bypass was introduced in E. coli . MMC bypass provides an alternative route for malonyl-CoA synthesis. MMC bypass alters precursor specificity for malonyl-CoA synthesis. MMC redirects carbon flux from the TCA cycle to FFA synthesis during bypass. Increasing precursor availability led to a 2.5-fold increase in FFA production. Abstract: This study investigated the effect of the methylmalonyl-CoA carboxyltransferase (MMC) of Propionibacterium freudenreichii on production of free fatty acid (FFA) in Escherichia coli . Overexpression of the MMC exhibited a 44% increase in FFA titer. Co-overexpression of MMC and phosphoenolpyruvate carboxylase (PPC), which supplies the MMC precursor, further improved the titer by 40%. Expression of malic enzyme (MaeB) led to a 23% increase in FFA titer in the acetyl-CoA carboxylase (ACC)-overexpressing cells, but no increase in the MMC-overexpressing cells. The highest FFA production in the MMC-overexpressing strain was achieved through the addition of aspartic acid, which can be converted into oxaloacetate (OAA), resulting in a 120% increased titer compared with that in the ACC-overexpressing strain. These findings demonstrate that MMC provides an alternative pathway for malonyl-CoA synthesis and increases fatty acid production.