Co-expression of cellulase and xylanase genes in Sacchromyces cerevisiae toward enhanced bioethanol production from corn stover

Abstract

Lignocellulose is considered as a good resource for producing renewable energy. Previous in vitro studies have shown the synergistic action between cellulase and xylanase during lignocellulose biohydrolysis. In order to achieve the same effect in S. cerevisiae to enhance the practical biotransformation, two recombinant Saccharomyces cerevisiae strains (INVSc1-CBH-CA and INVSc1-CBH-TS) with co-expressed cellulase and xylanase were constructed. The cellulase and xylanase activities in INVSc1-CBH-CA and INVSc1-CBH-TS were 716.43 U/mL and 205.13 U/mL, 931.27 U/mL and 413.70 U/mL, respectively. The recombinant S. cerevisiae can use the partly delignified corn stover (PDCS) more efficiently and more ethanol producted than S. cerevisiae only expressing cellulase. Fermentation with INVSc1-CBH-CA and INVSc1-CBH-TS using PDCS ethanol yields increased by 1.7 and 2.1 folds higher than INVSc1-CBH, 2.8 and 3.4 folds higher than the wild type S. cerevisiae. The strategy of co-expression cellulase and xylanase in saccharomyces cerevisiae is effective and can be a foundation to research the mechanism of synergy effect of cellulose and xylanase.