Methylglyoxal bypass identified as source of chiral contamination in l(+) and d(-)-lactate fermentations by recombinant Escherichia coli

Biotechnol Lett. 2006 Oct;28(19):1527-35. doi: 10.1007/s10529-006-9122-7. Epub 2006 Jul 26.


Two new strains of Escherichia coli B were engineered for the production of lactate with no detectable chiral impurity. All chiral impurities were eliminated by deleting the synthase gene (msgA) that converts dihydroxyacetone-phosphate to methylglyoxal, a precursor for both L: (+)- and D: (-)-lactate. Strain TG113 contains only native genes and produced optically pure D: (-)-lactate. Strain TG108 contains the ldhL gene from Pediococcus acidilactici and produced only L: (+)-lactate. In mineral salts medium containing 1 mM betaine, both strains produced over 115 g (1.3 mol) lactate from 12% (w/v) glucose, >95% theoretical yield.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biotechnology / methods*
  • Carbon-Oxygen Lyases / genetics
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism*
  • Fermentation
  • Gene Deletion
  • Glycolysis / genetics
  • Industrial Microbiology
  • Lactic Acid / biosynthesis*
  • Lactic Acid / chemistry
  • Pyruvaldehyde / metabolism*
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Stereoisomerism


  • Recombinant Proteins
  • Lactic Acid
  • Pyruvaldehyde
  • Carbon-Oxygen Lyases
  • methylglyoxal synthase