Engineering a Synthetic, Catabolically Orthogonal Coculture System for Enhanced Conversion of Lignocellulose-Derived Sugars to Ethanol

Andrew D. Flores, E. Zeynep Ayla, David R. Nielsen, Xuan Wang

Research output: Contribution to journalArticle

6 Scopus citations


Fermentation of lignocellulosic sugar mixtures is often suboptimal due to inefficient xylose catabolism and sequential sugar utilization caused by carbon catabolite repression. Unlike in conventional applications employing a single engineered strain, the alternative development of synthetic microbial communities facilitates the execution of complex metabolic tasks by exploiting the unique community features, including modularity, division of labor, and facile tunability. A series of synthetic, catabolically orthogonal coculture systems were systematically engineered, as derived from either wild-type Escherichia coli W or ethanologenic LY180. Net catabolic activities were effectively balanced by simple tuning of the inoculum ratio between specialist strains, which enabled coutilization (98% of 100 g L-1 total sugars) of glucose-xylose mixtures (2:1 by mass) for both culture systems in simple batch fermentations. The engineered ethanologenic cocultures achieved ethanol titer (46 g L-1), productivity (488 mg L-1 h-1), and yield (∼90% of theoretical maximum), which were all significantly increased compared to LY180 monocultures.

Original languageEnglish (US)
Pages (from-to)1089-1099
Number of pages11
JournalACS Synthetic Biology
Issue number5
StatePublished - May 17 2019



  • carbon catabolite repression
  • coculture
  • ethanol
  • lignocellulose conversion
  • microbial communities

ASJC Scopus subject areas

  • Biomedical Engineering
  • Biochemistry, Genetics and Molecular Biology (miscellaneous)

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