Metabolomic and [superscript 13]C-metabolic flux analysis of a xylose-consuming Saccharomyces cerevisiae strain expressing xylose isomerase
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Metabolic and c-metabolic.pdf
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3.15 MB
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Author(s)
Wasylenko, Thomas M.
Stephanopoulos, Gregory
Wasylenko, Thomas Michael
Alternative Title
Metabolomic and 13C-metabolic flux analysis of a xylose-consuming Saccharomyces cerevisiae strain expressing xylose isomerase
Date Issued
November 2014
Journal
Biotechnology and Bioengineering
Publisher
Wiley Blackwell
Citation
Wasylenko, Thomas M., and Gregory Stephanopoulos. “Metabolomic and 13 C-Metabolic Flux Analysis of a Xylose-Consuming Saccharomyces Cerevisiae Strain Expressing Xylose Isomerase: Xylose Metabolic Flux Analysis.” Biotechnology and Bioengineering 112.3 (2015): 470–483.
Version
Author's final manuscript
Abstract
Over the past two decades, significant progress has been made in the engineering of xylose-consuming Saccharomyces cerevisiae strains for production of lignocellulosic biofuels. However, the ethanol productivities achieved on xylose are still significantly lower than those observed on glucose for reasons that are not well understood. We have undertaken an analysis of central carbon metabolite pool sizes and metabolic fluxes on glucose and on xylose under aerobic and anaerobic conditions in a strain capable of rapid xylose assimilation via xylose isomerase in order to investigate factors that may limit the rate of xylose fermentation. We find that during xylose utilization the flux through the non-oxidative Pentose Phosphate Pathway (PPP) is high but the flux through the oxidative PPP is low, highlighting an advantage of the strain employed in this study. Furthermore, xylose fails to elicit the full carbon catabolite repression response that is characteristic of glucose fermentation in S. cerevisiae. We present indirect evidence that the incomplete activation of the fermentation program on xylose results in a bottleneck in lower glycolysis, leading to inefficient re-oxidation of NADH produced in glycolysis.
MIT Department
Massachusetts Institute of Technology. Department of Chemical Engineering
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Creative Commons Attribution-Noncommercial-Share Alike
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DOI of Published Version
https://doi.org/10.1002/bit.25447
