Development and evaluation of efficient recombinant Escherichia coli strains for the production of 3‐hydroxypropionic acid from glycerol

Abstract

3-Hydroxypropionic acid (3-HP) is a commercially valuable chemical with the potential to be a key building block for deriving many industrially important chemicals. However, its biological production has not been well documented. Our previous study demonstrated the feasibility of producing 3-HP from glycerol using the recombinant Escherichia coli SH254 expressing glycerol dehydratase (DhaB) and aldehyde dehydrogenase (AldH), and reported that an "imbalance between the two enzymes" and the "instability of the first enzyme DhaB" were the major factors limiting 3-HP production. In this study, the efficiency of the recombinant strain(s) was improved by expressing DhaB and AldH in two compatible isopropyl-thio-beta-galactoside (IPTG) inducible plasmids along with glycerol dehydratase reactivase (GDR). The expression levels of the two proteins were measured. It was found that the changes in protein expression were associated with their enzymatic activity and balance. While cloning an alternate aldehyde dehydrogenase (ALDH), alpha-ketoglutaric semialdehyde dehydrogenase (KGSADH), instead of AldH, the recombinant E. coli SH-BGK1 showed the highest level of 3-HP production (2.8 g/L) under shake-flask conditions. When an aerobic fed-batch process was carried out under bioreactor conditions at pH 7.0, the recombinant SH-BGK1 produced 38.7 g 3-HP/L with an average yield of 35%. This article reports the highest level of 3-HP production from glycerol thus far.

Biological Production of 3-Hydroxypropionic Acid: An Update on the Current Status

“…It contains two functional groups (a carboxyl group and a β-hydroxyl group), which makes it attractive to serve as an excellent versatile platform for the production of a variety of high added-value chemicals through chemical modification reactions [1]. The compounds that can be produced from 3HP include 1,3-propanediol, acrylic acid, acrylamide, acrylonitrile, propiolactone, malonic acid, homopolymers, and heteropolymers [2,3]. These compounds have a broad range of applications, and can be used for the production of adhesives, polymers, plastic packaging, fibers, cleaning agents, and resins.…”

Transformation of Biomass into Commodity Chemicals Using Enzymes or Cells

“…So far, the highest published level of production for this pathway is 39 g/L at 35 % yield using recombinant E. coli SH-BGK1. 274 This strain required (expensive) coenzyme B12 supplementation for activity of glycerol dehydratase, in the first step in the pathway. The dehydration leads to 3-hydroxypropanal upon keto-enol tautomerization, and subsequent reduction yields 3-hydroxypropionate.…”

Gene Arrangements in Expression Vector Affect 3-Hydroxypropionic Acid Production in Klebsiella pneumoniae

“…Because of the low activities of most AldHs identified so far, plasmid-dependent overexpression remains the predominant strategy for diverting carbon flux towards 3-HP. Park and his coworkers reported that 38.7 g/L of 3-HP was produced through over-expression of dhaB and aldh in E. coli [14]. Recently, another research group from China reported pronounced concentration of both 3-HP and 1,3-PDO generated by only expressing aldh [10].…”

“…Therefore, it appears that uncovered bottlenecks exist, which highly limits 3-HP production [14]. For instance, the catalytic imbalance between GDHt and AldH may restrict 3-HP biosynthesis.…”