TY - JOUR
T1 - Bioprospecting of native efflux pumps to enhance furfural tolerance in ethanologenic Escherichia coli
AU - Kurgan, Gavin
AU - Panyon, Larry A.
AU - Rodriguez-Sanchez, Yesenia
AU - Pacheco, Eric
AU - Nieves, Lizbeth M.
AU - Mann, Robert
AU - Nielsen, David
AU - Wang, Xuan
N1 - Funding Information:
This work was supported by the National Science Foundation (CBET-1511637) and start-up funds from Arizona State University (ASU). Robert Mann is supported by an ASU SOLUR fellowship. We thank the Ingram laboratory at the University of Florida providing the strains LY180 and XW129 and the plasmid pTrc99A-pntAB. We thank the Chapman laboratory at the University of Michigan, Ann Arbor, for providing plasmid pCA24N. We also thank members of the Wang laboratory for helpful discussions and review of the manuscript.
Publisher Copyright:
© 2019 American Society for Microbiology.
PY - 2019/3/1
Y1 - 2019/3/1
N2 - Efficient microbial conversion of lignocellulose into valuable products is often hindered by the presence of furfural, a dehydration product of pentoses in hemicellulose sugar syrups derived from woody biomass. For a cost-effective lignocellulose microbial conversion, robust biocatalysts are needed that can tolerate toxic inhibitors while maintaining optimal metabolic activities. A comprehensive plasmidbased library encoding native multidrug resistance (MDR) efflux pumps, porins, and select exporters from Escherichia coli was screened for furfural tolerance in an ethanologenic E. coli strain. Small multidrug resistance (SMR) pumps, such as SugE and MdtJI, as well as a lactate/glycolate:H+ symporter, LldP, conferred furfural tolerance in liquid culture tests. Expression of the SMR pump potentially increased furfural efflux and cellular viability upon furfural assault, suggesting novel activities for SMR pumps as furfural efflux proteins. Furthermore, induced expression of mdtJI enhanced ethanol fermentative production of LY180 in the presence of furfural or 5-hydroxymethylfurfural, further demonstrating the applications of SMR pumps. This work describes an effective approach to identify useful efflux systems with desired activities for nonnative toxic chemicals and provides a platform to further enhance furfural efflux by protein engineering and mutagenesis.
AB - Efficient microbial conversion of lignocellulose into valuable products is often hindered by the presence of furfural, a dehydration product of pentoses in hemicellulose sugar syrups derived from woody biomass. For a cost-effective lignocellulose microbial conversion, robust biocatalysts are needed that can tolerate toxic inhibitors while maintaining optimal metabolic activities. A comprehensive plasmidbased library encoding native multidrug resistance (MDR) efflux pumps, porins, and select exporters from Escherichia coli was screened for furfural tolerance in an ethanologenic E. coli strain. Small multidrug resistance (SMR) pumps, such as SugE and MdtJI, as well as a lactate/glycolate:H+ symporter, LldP, conferred furfural tolerance in liquid culture tests. Expression of the SMR pump potentially increased furfural efflux and cellular viability upon furfural assault, suggesting novel activities for SMR pumps as furfural efflux proteins. Furthermore, induced expression of mdtJI enhanced ethanol fermentative production of LY180 in the presence of furfural or 5-hydroxymethylfurfural, further demonstrating the applications of SMR pumps. This work describes an effective approach to identify useful efflux systems with desired activities for nonnative toxic chemicals and provides a platform to further enhance furfural efflux by protein engineering and mutagenesis.
KW - Escherichia coli
KW - Furfural
KW - Lignocellulose
KW - Metabolic engineering
KW - Multidrug resistance pumps
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U2 - 10.1128/AEM.02985-18
DO - 10.1128/AEM.02985-18
M3 - Article
C2 - 30635383
AN - SCOPUS:85062591786
SN - 0099-2240
VL - 85
JO - Applied and environmental microbiology
JF - Applied and environmental microbiology
IS - 6
M1 - e02985-18
ER -