Campus Units

Chemical and Biological Engineering, Microbiology, Ames Laboratory, NSF Engineering Research Center for Biorenewable Chemicals

Document Type


Research Focus Area

Biorenewables, Renewable Energy

Publication Version

Published Version

Publication Date


Journal or Book Title

Frontiers in Microbiology



First Page





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.


This article is published as Gao, Meirong, Deon Ploessl, and Zengyi Shao, "Enhancing the Co-utilization of Biomass-derived Mixed Sugars by Yeasts." Frontiers in Microbiology 9 (2019): 3264. doi: 10.3389/fmicb.2018.03264. Posted with permission.

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Copyright Owner

Gao, Ploessl and Shao



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