Abstract
Supply of NAD(P)H is a key factor in microbial production of xylitol from xylose. To facilitate NAD(P)H supplementation, acetaldehyde dehydrogenase 6 (ALD6) and acetyl-CoA synthetase 1 (ACS1) were overexpressed in recombinant Saccharomyces cerevisiae harboring the Pichia stipitis xylose reductase (XR) gene. In-vitro activity analysis confirmed the functional expression of both enzymes. Glucose-limited fed-batch fermentations of Saccharomyces cerevisiae BJ3505:δXR strains overexpressing ACS1 and/or ALD6 were performed by feeding 600. g/L glucose in the presence of 100. g/L xylose. Among them, ACS1 overexpression gave the best result of xylitol production: 91.3. g/L xylitol concentration and 1.76. g/L. h xylitol productivity, which were 25% and 11% increase, relative to those of the control and ALD6-overexpressing strains. Considering the changes of cell growth, ethanol and acetate production, a remarkable enhancement of xylitol production by ACS1 overexpression seemed be ascribed to energy and NAD(P)H generation through a metabolism from acetaldehyde to acetyl-CoA and TCA cycle.
Original language | English |
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Pages (from-to) | 15-19 |
Number of pages | 5 |
Journal | Biocatalysis and Agricultural Biotechnology |
Volume | 1 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2012 Jan |
Keywords
- Acetaldehyde dehydrogenase 6
- Acetyl-CoA synthetase 1
- NAD(P)H
- Saccharomyces cerevisiae
- Xylitol
- Xylose reductase
ASJC Scopus subject areas
- Biotechnology
- Food Science
- Bioengineering
- Applied Microbiology and Biotechnology
- Agronomy and Crop Science