2. Academic Validation
  3. Production of D-Glyceric acid from D-Galacturonate in Escherichia coli

Production of D-Glyceric acid from D-Galacturonate in Escherichia coli

  • J Ind Microbiol Biotechnol. 2020 Dec;47(12):1075-1081. doi: 10.1007/s10295-020-02323-2.
Kevin J Fox 1,  Kristala L J Prather 2
Affiliations

Affiliations

  • 1 Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
  • 2 Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA. kljp@mit.edu.
PMID: 33057913 DOI: 10.1007/s10295-020-02323-2
Abstract

A microbial production platform has been developed in Escherichia coli to synthesize D-glyceric acid from D-galacturonate. The expression of uronate dehydrogenase (udh) from Pseudomonas syringae and galactarolactone isomerase (Gli) from Agrobacterium fabrum, along with the inactivation of garK, encoding for glycerate kinase, enables D-glyceric acid accumulation by utilizing the endogenous expression of galactarate dehydratase (garD), 5-keto-4-deoxy-D-glucarate aldolase (garL), and 2-hydroxy-3-oxopropionate reductase (garR). Optimization of carbon flux through the elimination of competing metabolic pathways led to the development of a ΔgarKΔhyiΔglxKΔuxaC mutant strain that produced 4.8 g/l of D-glyceric acid from D-galacturonate, with an 83% molar yield. Cultivation in a minimal medium produced similar yields and demonstrated that galactose or glycerol serve as possible carbon co-feeds for industrial production. This novel platform represents an alternative for the production of D-glyceric acid, an industrially relevant chemical, that addresses current challenges in using acetic acid bacteria for its synthesis: increasing yield, enantio-purity and biological stability.

Keywords

D-glyceric acid; Escherichia coli; Metabolic engineering.

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