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Reduced oxidative pentose phosphate pathway flux in recombinant xylose-utilizing Saccharomyces cerevisiae strains improves the ethanol yield from xylose.

Jeppsson, Marie LU ; Johansson, Björn LU ; Hahn-Hägerdal, Bärbel LU and Gorwa-Grauslund, Marie-Francoise LU (2002) In Applied and Environmental Microbiology 68(4). p.1604-1609
Abstract
In recombinant, xylose-fermenting Saccharomyces cerevisiae, about 30% of the consumed xylose is converted to xylitol. Xylitol production results from a cofactor imbalance, since xylose reductase uses both NADPH and NADH, while xylitol dehydrogenase uses only NAD(+). In this study we increased the ethanol yield and decreased the xylitol yield by lowering the flux through the NADPH-producing pentose phosphate pathway. The pentose phosphate pathway was blocked either by disruption of the GND1 gene, one of the isogenes of 6-phosphogluconate dehydrogenase, or by disruption of the ZWF1 gene, which encodes glucose 6-phosphate dehydrogenase. Decreasing the phosphoglucose isomerase activity by 90% also lowered the pentose phosphate pathway flux.... (More)
In recombinant, xylose-fermenting Saccharomyces cerevisiae, about 30% of the consumed xylose is converted to xylitol. Xylitol production results from a cofactor imbalance, since xylose reductase uses both NADPH and NADH, while xylitol dehydrogenase uses only NAD(+). In this study we increased the ethanol yield and decreased the xylitol yield by lowering the flux through the NADPH-producing pentose phosphate pathway. The pentose phosphate pathway was blocked either by disruption of the GND1 gene, one of the isogenes of 6-phosphogluconate dehydrogenase, or by disruption of the ZWF1 gene, which encodes glucose 6-phosphate dehydrogenase. Decreasing the phosphoglucose isomerase activity by 90% also lowered the pentose phosphate pathway flux. These modifications all resulted in lower xylitol yield and higher ethanol yield than in the control strains. TMB3255, carrying a disruption of ZWF1, gave the highest ethanol yield (0.41 g g(-1)) and the lowest xylitol yield (0.05 g g(-1)) reported for a xylose-fermenting recombinant S. cerevisiae strain, but also an 84% lower xylose consumption rate. The low xylose fermentation rate is probably due to limited NADPH-mediated xylose reduction. Metabolic flux modeling of TMB3255 confirmed that the NADPH-producing pentose phosphate pathway was blocked and that xylose reduction was mediated only by NADH, leading to a lower rate of xylose consumption. These results indicate that xylitol production is strongly connected to the flux through the oxidative part of the pentose phosphate pathway. (Less)
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published
subject
keywords
Ethanol : metabolism, Fungal Proteins : genetics, Fungal Proteins : metabolism, Genetic Engineering : methods, Oxidation-Reduction, Pentosephosphate Pathway : genetics, Pentosephosphate Pathway : physiology, Recombination, Genetic, Saccharomyces cerevisiae : enzymology, Support, Saccharomyces cerevisiae : genetics, Fermentation, Non-U.S. Gov't, Xylose : genetics, Xylose : metabolism
in
Applied and Environmental Microbiology
volume
68
issue
4
pages
1604 - 1609
publisher
American Society for Microbiology
external identifiers
  • wos:000174842200016
  • pmid:11916674
  • scopus:0036208491
ISSN
0099-2240
DOI
10.1128/AEM.68.4.1604-1609.2002
language
English
LU publication?
yes
id
48a097dc-4402-4900-99c6-de0c88c30f2f (old id 107215)
date added to LUP
2007-06-28 13:45:39
date last changed
2017-12-10 03:38:34
@article{48a097dc-4402-4900-99c6-de0c88c30f2f,
  abstract     = {In recombinant, xylose-fermenting Saccharomyces cerevisiae, about 30% of the consumed xylose is converted to xylitol. Xylitol production results from a cofactor imbalance, since xylose reductase uses both NADPH and NADH, while xylitol dehydrogenase uses only NAD(+). In this study we increased the ethanol yield and decreased the xylitol yield by lowering the flux through the NADPH-producing pentose phosphate pathway. The pentose phosphate pathway was blocked either by disruption of the GND1 gene, one of the isogenes of 6-phosphogluconate dehydrogenase, or by disruption of the ZWF1 gene, which encodes glucose 6-phosphate dehydrogenase. Decreasing the phosphoglucose isomerase activity by 90% also lowered the pentose phosphate pathway flux. These modifications all resulted in lower xylitol yield and higher ethanol yield than in the control strains. TMB3255, carrying a disruption of ZWF1, gave the highest ethanol yield (0.41 g g(-1)) and the lowest xylitol yield (0.05 g g(-1)) reported for a xylose-fermenting recombinant S. cerevisiae strain, but also an 84% lower xylose consumption rate. The low xylose fermentation rate is probably due to limited NADPH-mediated xylose reduction. Metabolic flux modeling of TMB3255 confirmed that the NADPH-producing pentose phosphate pathway was blocked and that xylose reduction was mediated only by NADH, leading to a lower rate of xylose consumption. These results indicate that xylitol production is strongly connected to the flux through the oxidative part of the pentose phosphate pathway.},
  author       = {Jeppsson, Marie and Johansson, Björn and Hahn-Hägerdal, Bärbel and Gorwa-Grauslund, Marie-Francoise},
  issn         = {0099-2240},
  keyword      = {Ethanol : metabolism,Fungal Proteins : genetics,Fungal Proteins : metabolism,Genetic Engineering : methods,Oxidation-Reduction,Pentosephosphate Pathway : genetics,Pentosephosphate Pathway : physiology,Recombination,Genetic,Saccharomyces cerevisiae : enzymology,Support,Saccharomyces cerevisiae : genetics,Fermentation,Non-U.S. Gov't,Xylose : genetics,Xylose : metabolism},
  language     = {eng},
  number       = {4},
  pages        = {1604--1609},
  publisher    = {American Society for Microbiology},
  series       = {Applied and Environmental Microbiology},
  title        = {Reduced oxidative pentose phosphate pathway flux in recombinant xylose-utilizing Saccharomyces cerevisiae strains improves the ethanol yield from xylose.},
  url          = {http://dx.doi.org/10.1128/AEM.68.4.1604-1609.2002},
  volume       = {68},
  year         = {2002},
}