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image/svg+xml Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao Closed Access logo, derived from PLoS Open Access logo. This version with transparent background. http://commons.wikimedia.org/wiki/File:Closed_Access_logo_transparent.svg Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao Applied Microbiology...arrow_drop_down
image/svg+xml Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao Closed Access logo, derived from PLoS Open Access logo. This version with transparent background. http://commons.wikimedia.org/wiki/File:Closed_Access_logo_transparent.svg Jakob Voss, based on art designer at PLoS, modified by Wikipedia users Nina and Beao
Applied Microbiology and Biotechnology
Article . 2012 . Peer-reviewed
License: Springer TDM
Data sources: Crossref
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Implementation of a transhydrogenase-like shunt to counter redox imbalance during xylose fermentation in Saccharomyces cerevisiae

Authors: Hiroyuki, Suga; Fumio, Matsuda; Tomohisa, Hasunuma; Jun, Ishii; Akihiko, Kondo;

Implementation of a transhydrogenase-like shunt to counter redox imbalance during xylose fermentation in Saccharomyces cerevisiae

Abstract

Three enzymes responsible for the transhydrogenase-like shunt, including malic enzyme (encoded by MAE1), malate dehydrogenase (MDH2), and pyruvate carboxylase (PYC2), were overexpressed to regulate the redox state in xylose-fermenting recombinant Saccharomyces cerevisiae. The YPH499XU/MAE1 strain was constructed by overexpressing native Mae1p in the YPH499XU strain expressing xylose reductase and xylitol dehydrogenase from Scheffersomyces stipitis, and native xylulokinase. Analysis of the xylose fermentation profile under semi-anaerobic conditions revealed that the ethanol yield in the YPH499XU/MAE1 strain (0.38 ± 0.01 g g⁻¹ xylose consumed) was improved from that of the control strain (0.31 ± 0.01 g g⁻¹ xylose consumed). Reduced xylitol production was also observed in YPH499XU/MAE1, suggesting that the redox balance was altered by Mae1p overexpression. Analysis of intracellular metabolites showed that the redox imbalance during xylose fermentation was partly relieved in the transformant. The specific ethanol production rate in the YPH499XU/MAE1-MDH2 strain was 1.25-fold higher than that of YPH499XU/MAE1 due to the additional overexpression of Mdh2p, whereas the ethanol yield was identical to that of YPH499XU/MAE1. The specific xylose consumption rate was drastically increased in the YPH499XU/MAE1-MDH2-PYC2 strain. However, poor ethanol yield as well as increased production of xylitol was observed. These results demonstrate that the transhydrogenase function implemented in S. cerevisiae can regulate the redox state of yeast cells.

Related Organizations
Keywords

Saccharomyces cerevisiae Proteins, Xylose, Ethanol, D-Xylulose Reductase, Saccharomyces cerevisiae, Fungal Proteins, Metabolic Engineering, Aldehyde Reductase, Malate Dehydrogenase, Fermentation, Saccharomycetales, Oxidation-Reduction

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citations
This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Citations provided by BIP!
popularity
This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.
BIP!Popularity provided by BIP!
influence
This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).
BIP!Influence provided by BIP!
impulse
This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.
BIP!Impulse provided by BIP!
27
Top 10%
Top 10%
Top 10%