@ARTICLE{10.3389/fmicb.2018.03264, AUTHOR={Gao, Meirong and Ploessl, Deon and Shao, Zengyi}, TITLE={Enhancing the Co-utilization of Biomass-Derived Mixed Sugars by Yeasts}, JOURNAL={Frontiers in Microbiology}, VOLUME={9}, YEAR={2019}, URL={https://www.frontiersin.org/articles/10.3389/fmicb.2018.03264}, DOI={10.3389/fmicb.2018.03264}, ISSN={1664-302X}, ABSTRACT={Plant biomass is a promising carbon source for producing value-added chemicals, including transportation biofuels, polymer precursors, and various additives. Most engineered microbial hosts and a select group of wild-type species can metabolize mixed sugars including oligosaccharides, hexoses, and pentoses that are hydrolyzed from plant biomass. However, most of these microorganisms consume glucose preferentially to non-glucose sugars through mechanisms generally defined as carbon catabolite repression. The current lack of simultaneous mixed-sugar utilization limits achievable titers, yields, and productivities. Therefore, the development of microbial platforms capable of fermenting mixed sugars simultaneously from biomass hydrolysates is essential for economical industry-scale production, particularly for compounds with marginal profits. This review aims to summarize recent discoveries and breakthroughs in the engineering of yeast cell factories for improved mixed-sugar co-utilization based on various metabolic engineering approaches. Emphasis is placed on enhanced non-glucose utilization, discovery of novel sugar transporters free from glucose repression, native xylose-utilizing microbes, consolidated bioprocessing (CBP), improved cellulase secretion, and creation of microbial consortia for improving mixed-sugar utilization. Perspectives on the future development of biorenewables industry are provided in the end.} }