The XylR variant (R121C and P363S) releases arabinose-induced catabolite repression on xylose fermentation and enhances coutilization of lignocellulosic sugar mixtures

Rodrigo Martinez, Andrew D. Flores, Matthew E. Dufault, Xuan Wang

Research output: Contribution to journalArticlepeer-review

3 Scopus citations

Abstract

Microbial production of fuels and chemicals from lignocellulosic biomass provides a promising alternative to conventional petroleum-derived routes. However, the heterogeneous sugar composition of lignocellulose prevents efficient microbial sugar co-fermentation due to carbon catabolite repression, which negatively affects production metrics. We previously discovered that a mutant copy of the transcriptional regulator XylR (P363S and R121C; denoted as XylR*) in Escherichia coli has a higher DNA-binding affinity than wild-type XylR, leading to a stronger activation of the d-xylose catabolic genes and a release from glucose-induced repression on xylose fermentation. Here, we showed that XylR* also releases l-arabinose-induced repression on xylose fermentation through altered transcriptional control, enhancing co-fermentation of arabinose–xylose sugar mixtures in wild-type E. coli. Integrating xylR* into an ethanologenic E. coli resulted in the coutilization of 96% of the provided glucose–xylose–arabinose mixtures (120 g/L total sugars supplied) with an ethanol yield higher than 90% of the theoretical maximum by simple batch fermentations.

Original languageEnglish (US)
Pages (from-to)3476-3481
Number of pages6
JournalBiotechnology and bioengineering
Volume116
Issue number12
DOIs
StatePublished - Dec 1 2019
Externally publishedYes

Keywords

  • Escherichia coli
  • XylR
  • carbon catabolite repression
  • lignocellulose

ASJC Scopus subject areas

  • Biotechnology
  • Bioengineering
  • Applied Microbiology and Biotechnology

Fingerprint Dive into the research topics of 'The XylR variant (R121C and P363S) releases arabinose-induced catabolite repression on xylose fermentation and enhances coutilization of lignocellulosic sugar mixtures'. Together they form a unique fingerprint.

Cite this