Abstract
The aim of this study was to engineer cellodextrin transporter 2 (CDT-2) from Neurospora crassa for improved cellobiose fermentation under lower pH conditions by Saccharomyces cerevisiae. Through directed evolution, a mutant CDT-2 capable of facilitating cellobiose fermentation under lower pH conditions was obtained. Specifically, a library of CDT-2 mutants with GFP fusion was screened by flow cytometry and then serial subcultured to isolate a CDT-2 mutant capable of transporting cellobiose under acidic conditions. The engineered S. cerevisiae expressing the isolated mutant CDT-2 (I96N/T487A) produced ethanol with a specific cellobiose consumption rate of 0.069 g/g cell/h, which was 51% and 55% higher than those of the strains harboring wild-type CDT-1 and CDT-2 in a minimal medium with 2 g/L of acetic acid.
Original language | English (US) |
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Pages (from-to) | 1469-1475 |
Number of pages | 7 |
Journal | Bioresource Technology |
Volume | 245 |
DOIs | |
State | Published - Dec 2017 |
Keywords
- Cellobiose
- Cellodextrin transporter
- Low pH conditions
- Saccharomyces cerevisiae
- Transporter engineering
ASJC Scopus subject areas
- Bioengineering
- Environmental Engineering
- Renewable Energy, Sustainability and the Environment
- Waste Management and Disposal