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Kinetic modelling reveals current limitations in the production of ethanol from xylose by recombinant Saccharomyces cerevisiae.

Skorupa Parachin, Nadia LU ; Bergdahl, Basti LU ; van Niel, Ed LU and Gorwa-Grauslund, Marie-Francoise LU (2011) In Metabolic Engineering 13. p.508-517
Abstract
Saccharomyces cerevisiae lacks the ability to ferment the pentose sugar xylose that is the second most abundant sugar in nature. Therefore two different xylose catabolic pathways have been heterologously expressed in S. cerevisiae. Whereas the xylose reductase (XR)-xylitol dehydrogenase (XDH) pathway leads to the production of the by-product xylitol, the xylose isomerase (XI) pathway results in significantly lower xylose consumption. In this study, kinetic models including the reactions ranging from xylose transport into the cell to the phosphorylation of xylulose to xylulose 5-P were constructed. They were used as prediction tools for the identification of putative targets for the improvement of xylose utilization in S. cerevisiae strains... (More)
Saccharomyces cerevisiae lacks the ability to ferment the pentose sugar xylose that is the second most abundant sugar in nature. Therefore two different xylose catabolic pathways have been heterologously expressed in S. cerevisiae. Whereas the xylose reductase (XR)-xylitol dehydrogenase (XDH) pathway leads to the production of the by-product xylitol, the xylose isomerase (XI) pathway results in significantly lower xylose consumption. In this study, kinetic models including the reactions ranging from xylose transport into the cell to the phosphorylation of xylulose to xylulose 5-P were constructed. They were used as prediction tools for the identification of putative targets for the improvement of xylose utilization in S. cerevisiae strains engineered for higher level of the non-oxidative pentose phosphate pathway (PPP) enzymes, higher xylulokinase and inactivated GRE3 gene encoding an endogenous NADPH-dependent aldose reductase. For both pathways, the in silico analyses identified a need for even higher xylulokinase (XK) activity. In a XR-XDH strain expressing an integrated copy of the Escherichia coli XK encoding gene xylB about a six-fold reduction of xylitol formation was confirmed under anaerobic conditions. Similarly overexpression of the xylB gene in a XI strain increased the aerobic growth rate on xylose by 21%. In contrast to the in silico predictions, the aerobic growth also increased 24% when the xylose transporter gene GXF1 from Candida intermedia was overexpressed together with xylB in the XI strain. Under anaerobic conditions, the XI strains overexpressing xylB gene and the combination of xylB and GFX1 genes consumed 27% and 37% more xylose than the control strain. (Less)
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author
organization
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Contribution to journal
publication status
published
subject
in
Metabolic Engineering
volume
13
pages
508 - 517
publisher
Elsevier
external identifiers
  • wos:000294291200007
  • pmid:21642010
  • scopus:80052037221
ISSN
1096-7176
DOI
10.1016/j.ymben.2011.05.005
language
English
LU publication?
yes
id
4cd042bc-47dc-4fb7-b84d-d2834aca2c8e (old id 2008510)
date added to LUP
2011-07-21 11:11:26
date last changed
2017-10-08 03:09:47
@article{4cd042bc-47dc-4fb7-b84d-d2834aca2c8e,
  abstract     = {Saccharomyces cerevisiae lacks the ability to ferment the pentose sugar xylose that is the second most abundant sugar in nature. Therefore two different xylose catabolic pathways have been heterologously expressed in S. cerevisiae. Whereas the xylose reductase (XR)-xylitol dehydrogenase (XDH) pathway leads to the production of the by-product xylitol, the xylose isomerase (XI) pathway results in significantly lower xylose consumption. In this study, kinetic models including the reactions ranging from xylose transport into the cell to the phosphorylation of xylulose to xylulose 5-P were constructed. They were used as prediction tools for the identification of putative targets for the improvement of xylose utilization in S. cerevisiae strains engineered for higher level of the non-oxidative pentose phosphate pathway (PPP) enzymes, higher xylulokinase and inactivated GRE3 gene encoding an endogenous NADPH-dependent aldose reductase. For both pathways, the in silico analyses identified a need for even higher xylulokinase (XK) activity. In a XR-XDH strain expressing an integrated copy of the Escherichia coli XK encoding gene xylB about a six-fold reduction of xylitol formation was confirmed under anaerobic conditions. Similarly overexpression of the xylB gene in a XI strain increased the aerobic growth rate on xylose by 21%. In contrast to the in silico predictions, the aerobic growth also increased 24% when the xylose transporter gene GXF1 from Candida intermedia was overexpressed together with xylB in the XI strain. Under anaerobic conditions, the XI strains overexpressing xylB gene and the combination of xylB and GFX1 genes consumed 27% and 37% more xylose than the control strain.},
  author       = {Skorupa Parachin, Nadia and Bergdahl, Basti and van Niel, Ed and Gorwa-Grauslund, Marie-Francoise},
  issn         = {1096-7176},
  language     = {eng},
  pages        = {508--517},
  publisher    = {Elsevier},
  series       = {Metabolic Engineering},
  title        = {Kinetic modelling reveals current limitations in the production of ethanol from xylose by recombinant Saccharomyces cerevisiae.},
  url          = {http://dx.doi.org/10.1016/j.ymben.2011.05.005},
  volume       = {13},
  year         = {2011},
}