Biotechnology Letters

, Volume 28, Issue 19, pp 1527–1535

Methylglyoxal Bypass Identified as Source of Chiral Contamination in l(+) and d(−)-lactate Fermentations by Recombinant Escherichia coli

  • T. B. Grabar
  • S. Zhou
  • K. T. Shanmugam
  • L. P. Yomano
  • L. O. Ingram
Original Paper

DOI: 10.1007/s10529-006-9122-7

Cite this article as:
Grabar, T.B., Zhou, S., Shanmugam, K.T. et al. Biotechnol Lett (2006) 28: 1527. doi:10.1007/s10529-006-9122-7

Abstract

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.

Keywords

Lactate Betaine E. coli Methylglyoxal mgsA Polylactic acid 

Copyright information

© Springer Science+Business Media B.V. 2006

Authors and Affiliations

  • T. B. Grabar
    • 1
  • S. Zhou
    • 2
  • K. T. Shanmugam
    • 1
  • L. P. Yomano
    • 1
  • L. O. Ingram
    • 1
  1. 1.Department of Microbiology and Cell ScienceUniversity of FloridaGainesvilleUSA
  2. 2.Department of Biological SciencesNorthern Illinois UniversityDeKalbUSA

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