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Assessing the effect of d-xylose on the sugar signaling pathways of Saccharomyces cerevisiae in strains engineered for xylose transport and assimilation

Ofuji Osiro, Karen LU ; Brink, Daniel LU ; Borgström, Celina LU ; Wasserstrom, Lisa LU ; Carlquist, Magnus LU and Gorwa-Grauslund, Marie F LU (2018) In FEMS Yeast Research 18(1).
Abstract (Swedish)
One of the challenges of establishing an industrially competitive process to ferment lignocellulose to value-added products using Saccharomyces cerevisiae is to get efficient mixed sugar fermentations. Despite successful metabolic engineering strategies, the xylose assimilation rates of recombinant S. cerevisiae remain significantly lower than for the preferred carbon source, glucose. Previously, we established a panel of in vivo biosensor strains (TMB371X) where different promoters (HXT1/2/4p; SUC2p, CAT8p; TPS1p/2p, TEF4p) from the main sugar signaling pathways were coupled with the yEGFP3 gene, and observed that wild-type S. cerevisiae cannot sense extracellular xylose. Here, we expand upon these strains by adding a mutated galactose... (More)
One of the challenges of establishing an industrially competitive process to ferment lignocellulose to value-added products using Saccharomyces cerevisiae is to get efficient mixed sugar fermentations. Despite successful metabolic engineering strategies, the xylose assimilation rates of recombinant S. cerevisiae remain significantly lower than for the preferred carbon source, glucose. Previously, we established a panel of in vivo biosensor strains (TMB371X) where different promoters (HXT1/2/4p; SUC2p, CAT8p; TPS1p/2p, TEF4p) from the main sugar signaling pathways were coupled with the yEGFP3 gene, and observed that wild-type S. cerevisiae cannot sense extracellular xylose. Here, we expand upon these strains by adding a mutated galactose transporter (GAL2-N376F) with improved xylose affinity (TMB372X), and both the transporter and an oxidoreductase xylose pathway (TMB375X). On xylose, the TMB372X strains displayed population heterogeneities, which disappeared when carbon starvation was relieved by the addition of the xylose assimilation pathway (TMB375X). Furthermore, the signal in the TMB375X strains on high xylose (50 g/L) was very similar to the signal recorded on low glucose (≤5 g/L). This suggests that intracellular xylose triggers a similar signal to carbon limitation in cells that are actively metabolizing xylose, in turn causing the low assimilation rates. (Less)
Abstract
One of the challenges of establishing an industrially competitive process to ferment lignocellulose to value-added products using Saccharomyces cerevisiae is to get efficient mixed sugar fermentations. Despite successful metabolic engineering strategies, the xylose assimilation rates of recombinant S. cerevisiae remain significantly lower than for the preferred carbon source, glucose. Previously, we established a panel of in vivo biosensor strains (TMB371X) where different promoters (HXT1/2/4p; SUC2p, CAT8p; TPS1p/2p, TEF4p) from the main sugar signaling pathways were coupled with the yEGFP3 gene, and observed that wild-type S. cerevisiae cannot sense extracellular xylose. Here, we expand upon these strains by adding a mutated galactose... (More)
One of the challenges of establishing an industrially competitive process to ferment lignocellulose to value-added products using Saccharomyces cerevisiae is to get efficient mixed sugar fermentations. Despite successful metabolic engineering strategies, the xylose assimilation rates of recombinant S. cerevisiae remain significantly lower than for the preferred carbon source, glucose. Previously, we established a panel of in vivo biosensor strains (TMB371X) where different promoters (HXT1/2/4p; SUC2p, CAT8p; TPS1p/2p, TEF4p) from the main sugar signaling pathways were coupled with the yEGFP3 gene, and observed that wild-type S. cerevisiae cannot sense extracellular xylose. Here, we expand upon these strains by adding a mutated galactose transporter (GAL2-N376F) with improved xylose affinity (TMB372X), and both the transporter and an oxidoreductase xylose pathway (TMB375X). On xylose, the TMB372X strains displayed population heterogeneities, which disappeared when carbon starvation was relieved by the addition of the xylose assimilation pathway (TMB375X). Furthermore, the signal in the TMB375X strains on high xylose (50 g/L) was very similar to the signal recorded on low glucose (≤5 g/L). This suggests that intracellular xylose triggers a similar signal to carbon limitation in cells that are actively metabolizing xylose, in turn causing the low assimilation rates. (Less)
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published
subject
keywords
GFP biosensor, SNF1/Mig1p, saccharomyces cerevisiae, Snf3p/Rgt2p, XR/XDH, cAMP/PKA, flow cytometery, sugar sensing/signalling, xylose
in
FEMS Yeast Research
volume
18
issue
1
publisher
Elsevier
ISSN
1567-1364
DOI
10.1093/femsyr/fox096
language
English
LU publication?
yes
id
d7d1069e-972a-47e3-a79d-6605d86fb747
date added to LUP
2018-03-13 08:28:45
date last changed
2018-11-21 21:38:37
@article{d7d1069e-972a-47e3-a79d-6605d86fb747,
  abstract     = {One of the challenges of establishing an industrially competitive process to ferment lignocellulose to value-added products using Saccharomyces cerevisiae is to get efficient mixed sugar fermentations. Despite successful metabolic engineering strategies, the xylose assimilation rates of recombinant S. cerevisiae remain significantly lower than for the preferred carbon source, glucose. Previously, we established a panel of in vivo biosensor strains (TMB371X) where different promoters (HXT1/2/4p; SUC2p, CAT8p; TPS1p/2p, TEF4p) from the main sugar signaling pathways were coupled with the yEGFP3 gene, and observed that wild-type S. cerevisiae cannot sense extracellular xylose. Here, we expand upon these strains by adding a mutated galactose transporter (GAL2-N376F) with improved xylose affinity (TMB372X), and both the transporter and an oxidoreductase xylose pathway (TMB375X). On xylose, the TMB372X strains displayed population heterogeneities, which disappeared when carbon starvation was relieved by the addition of the xylose assimilation pathway (TMB375X). Furthermore, the signal in the TMB375X strains on high xylose (50 g/L) was very similar to the signal recorded on low glucose (≤5 g/L). This suggests that intracellular xylose triggers a similar signal to carbon limitation in cells that are actively metabolizing xylose, in turn causing the low assimilation rates.},
  author       = {Ofuji Osiro, Karen and Brink, Daniel and Borgström, Celina and Wasserstrom, Lisa and Carlquist, Magnus and Gorwa-Grauslund, Marie F},
  issn         = {1567-1364},
  keyword      = {GFP biosensor,SNF1/Mig1p,saccharomyces cerevisiae,Snf3p/Rgt2p,XR/XDH,cAMP/PKA,flow cytometery,sugar sensing/signalling,xylose},
  language     = {eng},
  month        = {02},
  number       = {1},
  publisher    = {Elsevier},
  series       = {FEMS Yeast Research},
  title        = {Assessing the effect of d-xylose on the sugar signaling pathways of Saccharomyces cerevisiae in strains engineered for xylose transport and assimilation},
  url          = {http://dx.doi.org/10.1093/femsyr/fox096},
  volume       = {18},
  year         = {2018},
}