This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Gokarn, R. R.
Right arrow Articles by Altman, E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gokarn, R. R.
Right arrow Articles by Altman, E.
Agricola
Right arrow Articles by Gokarn, R. R.
Right arrow Articles by Altman, E.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, May 2000, p. 1844-1850, Vol. 66, No. 5
0099-2240/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.

Metabolic Analysis of Escherichia coli in the Presence and Absence of the Carboxylating Enzymes Phosphoenolpyruvate Carboxylase and Pyruvate Carboxylase

R. R. Gokarn,dagger M. A. Eiteman,* and E. Altman

Center for Molecular BioEngineering, Department of Biological and Agricultural Engineering, University of Georgia, Athens, Georgia 30602

Received 24 September 1999/Accepted 10 February 2000

Fermentation patterns of Escherichia coli with and without the phosphoenolpyruvate carboxylase (PPC) and pyruvate carboxylase (PYC) enzymes were compared under anaerobic conditions with glucose as a carbon source. Time profiles of glucose and fermentation product concentrations were determined and used to calculate metabolic fluxes through central carbon pathways during exponential cell growth. The presence of the Rhizobium etli pyc gene in E. coli (JCL1242/pTrc99A-pyc) restored the succinate producing ability of E. coli ppc null mutants (JCL1242), with PYC competing favorably with both pyruvate formate lyase and lactate dehydrogenase. Succinate formation was slightly greater by JCL1242/pTrc99A-pyc than by cells which overproduced PPC (JCL1242/pPC201, ppc+), even though PPC activity in cell extracts of JCL1242/pPC201 (ppc+) was 40-fold greater than PYC activity in extracts of JCL1242/pTrc99a-pyc. Flux calculations indicate that during anaerobic metabolism the pyc+ strain had a 34% greater specific glucose consumption rate, a 37% greater specific rate of ATP formation, and a 6% greater specific growth rate compared to the ppc+ strain. In light of the important position of pyruvate at the juncture of NADH-generating pathways and NADH-dissimilating branches, the results show that when PPC or PYC is expressed, the metabolic network adapts by altering the flux to lactate and the molar ratio of ethanol to acetate formation.

* Corresponding author. Mailing address: 408 Driftmier Engineering Center, University of Georgia, Athens, GA 30602. Phone: (706) 542-0833. Fax: (706) 542-8806. E-mail: eiteman{at}bae.uga.edu.

dagger Present address: Biotechnology Group, Cargill, Inc., Navarre, MN 55331.

Applied and Environmental Microbiology, May 2000, p. 1844-1850, Vol. 66, No. 5
0099-2240/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:

  • Kim, P., Laivenieks, M., Vieille, C., Zeikus, J. G. (2004). Effect of Overexpression of Actinobacillus succinogenes Phosphoenolpyruvate Carboxykinase on Succinate Production in Escherichia coli. Appl. Environ. Microbiol. 70: 1238-1241 [Abstract] [Full Text]  
  • Polen, T., Rittmann, D., Wendisch, V. F., Sahm, H. (2003). DNA Microarray Analyses of the Long-Term Adaptive Response of Escherichia coli to Acetate and Propionate. Appl. Environ. Microbiol. 69: 1759-1774 [Abstract] [Full Text]  
  • Zhou, S., Causey, T. B., Hasona, A., Shanmugam, K. T., Ingram, L. O. (2003). Production of Optically Pure D-Lactic Acid in Mineral Salts Medium by Metabolically Engineered Escherichia coli W3110. Appl. Environ. Microbiol. 69: 399-407 [Abstract] [Full Text]  
  • March, J. C., Eiteman, M. A., Altman, E. (2002). Expression of an Anaplerotic Enzyme, Pyruvate Carboxylase, Improves Recombinant Protein Production in Escherichia coli. Appl. Environ. Microbiol. 68: 5620-5624 [Abstract] [Full Text]  
  • Vemuri, G. N., Eiteman, M. A., Altman, E. (2002). Effects of Growth Mode and Pyruvate Carboxylase on Succinic Acid Production by Metabolically Engineered Strains of Escherichia coli. Appl. Environ. Microbiol. 68: 1715-1727 [Abstract] [Full Text]  
  • Underwood, S. A., Buszko, M. L., Shanmugam, K. T., Ingram, L. O. (2002). Flux through Citrate Synthase Limits the Growth of Ethanologenic Escherichia coli KO11 during Xylose Fermentation. Appl. Environ. Microbiol. 68: 1071-1081 [Abstract] [Full Text]  
  • Chatterjee, R., Millard, C. S., Champion, K., Clark, D. P., Donnelly, M. I. (2001). Mutation of the ptsG Gene Results in Increased Production of Succinate in Fermentation of Glucose by Escherichia coli. Appl. Environ. Microbiol. 67: 148-154 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»