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Activation of cryptic xylose metabolism by a transcriptional activator Znf1 boosts up xylitol production in the engineered Saccharomyces cerevisiae lacking xylose suppressor BUD21 gene
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Document Title
Activation of cryptic xylose metabolism by a transcriptional activator Znf1 boosts up xylitol production in the engineered Saccharomyces cerevisiae lacking xylose suppressor BUD21 gene
Author
Songdech P, Intasit R, Yingchutrakul Y, Butkinaree C, Ratanakhanokchai K, Soontorngun N
Name from Authors Collection
Affiliations
King Mongkuts University of Technology Thonburi; National Science & Technology Development Agency - Thailand; King Mongkuts University of Technology Thonburi
Type
Article
Source Title
MICROBIAL CELL FACTORIES
Year
2022
Volume
21
Issue
3
Open Access
Green Published, gold
Publisher
BMC
DOI
10.1186/s12934-022-01757-w
Format
Abstract
Background: Xylitol is a valuable pentose sugar alcohol, used in the food and pharmaceutical industries. Biotechnological xylitol production is currently attractive due to possible conversion from abundant and low-cost industrial wastes or agricultural lignocellulosic biomass. In this study, the transcription factor Znf1 was characterised as being responsible for the activation of cryptic xylose metabolism in a poor xylose-assimilating S. cerevisiae for xylitol production. Results: The results suggest that the expression of several xylose-utilising enzyme genes, encoding xylose reductases for the reduction of xylose to xylitol was derepressed by xylose. Their expression and those of a pentose phosphate shunt and related pathways required for xylose utilisation were strongly activated by the transcription factor Znf1. Using an engineered S. cerevisiae strain overexpressing ZNF1 in the absence of the xylose suppressor bud21 Delta, xylitol production was maximally by approximately 1200% to 12.14 g/L of xylitol, corresponding to 0.23 g/g xylose consumed, during 10% (w/v) xylose fermentation. Proteomic analysis supported the role of Znf1 and Bud21 in modulating levels of proteins associated with carbon metabolism, xylose utilisation, ribosomal protein synthesis, and others. Increased tolerance to lignocellulosic inhibitors and improved cell dry weight were also observed in this engineered bud21 Delta + pLJ529-ZNF1 strain. A similar xylitol yield was achieved using fungus-pretreated rice straw hydrolysate as an eco-friendly and low-cost substrate. Conclusions: Thus, we identified the key modulators of pentose sugar metabolism, namely the transcription factor Znf1 and the suppressor Bud21, for enhanced xylose utilisation, providing a potential application of a generally recognised as safe yeast in supporting the sugar industry and the sustainable lignocellulose-based bioeconomy.
Industrial Classification
Knowledge Taxonomy Level 1
Knowledge Taxonomy Level 2
Knowledge Taxonomy Level 3
Funding Sponsor
National Research Council of Thailand, Thailand Science Research and Innovation (TSRI) Basic Research Fund [64A306000038]; Petchra Pra Jom Klao PhD scholarship [35/2558]; King Mongkut's University of Technology Thonburi through the KMUTT 55th Anniversary commemorative fund
License
CC BY
Rights
Authors
Publication Source
WOS