AEM
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
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 Sonderegger, M.
Right arrow Articles by Sauer, U.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Sonderegger, M.
Right arrow Articles by Sauer, U.
Agricola
Right arrow Articles by Sonderegger, M.
Right arrow Articles by Sauer, U.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, May 2004, p. 2892-2897, Vol. 70, No. 5
0099-2240/04/$08.00+0     DOI: 10.1128/AEM.70.5.2892-2897.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.

Metabolic Engineering of a Phosphoketolase Pathway for Pentose Catabolism in Saccharomyces cerevisiae

Marco Sonderegger, Michael Schümperli, and Uwe Sauer*

Institute of Biotechnology, ETH Zürich, CH-8093 Zürich, Switzerland

Received 12 November 2003/ Accepted 30 January 2004

Low ethanol yields on xylose hamper economically viable ethanol production from hemicellulose-rich plant material with Saccharomyces cerevisiae. A major obstacle is the limited capacity of yeast for anaerobic reoxidation of NADH. Net reoxidation of NADH could potentially be achieved by channeling carbon fluxes through a recombinant phosphoketolase pathway. By heterologous expression of phosphotransacetylase and acetaldehyde dehydrogenase in combination with the native phosphoketolase, we installed a functional phosphoketolase pathway in the xylose-fermenting Saccharomyces cerevisiae strain TMB3001c. Consequently the ethanol yield was increased by 25% because less of the by-product xylitol was formed. The flux through the recombinant phosphoketolase pathway was about 30% of the optimum flux that would be required to completely eliminate xylitol and glycerol accumulation. Further overexpression of phosphoketolase, however, increased acetate accumulation and reduced the fermentation rate. By combining the phosphoketolase pathway with the ald6 mutation, which reduced acetate formation, a strain with an ethanol yield 20% higher and a xylose fermentation rate 40% higher than those of its parent was engineered.

* Corresponding author. Mailing address: Institute of Biotechnology, ETH Zürich, CH-8093 Zürich, Switzerland. Phone: 41-1-633 36 72. Fax: 41-1-633 10 51. E-mail: sauer{at}biotech.biol.ethz.ch.

Applied and Environmental Microbiology, May 2004, p. 2892-2897, Vol. 70, No. 5
0099-2240/04/$08.00+0     DOI: 10.1128/AEM.70.5.2892-2897.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
J. Bacteriol. Microbiol. Mol. Biol. Rev. Eukaryot. Cell All ASM Journals

Copyright © 2004 by the American Society for Microbiology. All rights reserved.