Abstract

Bioconversion of lignocellulosic biomass into ethanol requires efficient xylose fermentation. Previously, we developed an engineered Saccharomyces cerevisiae strain, named SR8, through rational and inverse metabolic engineering strategies, thereby improving its xylose fermentation and ethanol production. However, its fermentation characteristics have not yet been fully evaluated. In this study, we investigated the xylose fermentation and metabolic profiles for ethanol production in the SR8 strain compared with native Scheffersomyces stipitis. The SR8 strain showed a higher maximum ethanol titer and xylose consumption rate when cultured with a high concentration of xylose, mixed sugars, and under anaerobic conditions than Sch. stipitis. However, its ethanol productivity was less on 40 g/L xylose as the sole carbon source, mainly due to the formation of xylitol and glycerol. Global metabolite profiling indicated different intracellular production rates of xylulose and glycerol-3-phosphate in the two strains. In addition, compared with Sch. stipitis, SR8 had increased abundances of metabolites from sugar metabolism and decreased abundances of metabolites from energy metabolism and free fatty acids. These results provide insights into how to control and balance redox cofactors for the production of fuels and chemicals from xylose by the engineered S. cerevisiae.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.