Journal of Industrial Microbiology and Biotechnology

, Volume 27, Issue 4, pp 259–264

Recombinant Escherichia coli engineered for production of L-lactic acid from hexose and pentose sugars

  • B S Dien
  • N N Nichols
  • R J Bothast

DOI: 10.1038/sj.jim.7000195

Cite this article as:
Dien, B., Nichols, N. & Bothast, R. J Ind Microbiol Biotech (2001) 27: 259. doi:10.1038/sj.jim.7000195
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Recombinant Escherichia coli have been constructed for the conversion of glucose as well as pentose sugars into L-lactic acid. The strains carry the lactate dehydrogenase gene from Streptococcus bovis on a low copy number plasmid for production of L-lactate. Three E. coli strains were transformed with the plasmid for producing L-lactic acid. Strains FBR9 and FBR11 were serially transferred 10 times in anaerobic cultures in sugar-limited medium containing glucose or xylose without selective antibiotic. An average of 96% of both FBR9 and FBR11 cells maintained pVALDH1 in anaerobic cultures. The fermentation performances of FBR9, FBR10, and FBR11 were compared in pH-controlled batch fermentations with medium containing 10% w/v glucose. Fermentation results were superior for FBR11, an E. coli B strain, compared to those observed for FBR9 or FBR10. FBR11 exhausted the glucose within 30 h, and the maximum lactic acid concentration (7.32% w/v) was 93% of the theoretical maximum. The other side-products detected were cell mass and succinic acid (0.5 g/l). Journal of Industrial Microbiology & Biotechnology (2001) 27, 259–264.

Keywords: lactic acid production; Escherichia coli; fermentation; pentoses

Copyright information

© Society for Industrial Microbiology 2001

Authors and Affiliations

  • B S Dien
    • 1
  • N N Nichols
    • 1
  • R J Bothast
    • 1
  1. 1.Fermentation Biochemistry Research Unit, National Center for Agricultural Utilization Research, USDA, Agricultural Research Service, 1815 North University Street, Peoria, IL 61604, USAUS