Co‐utilization of hexoses by a microconsortium of sugar‐specific E. coli strains

ABSTRACT Escherichia coli is an important commercial species used for production of biofuels, biopolymers, organic acids, sugar alcohols, and natural compounds. Processed biomass and agroindustrial byproducts serve as low‐cost nutrient sources and contain a variety of hexoses available for bioconver...

Full description

Saved in:
Bibliographic Details
Published in:Biotechnology and bioengineering 2017-10, Vol.114 (10), p.2309-2318
Main Authors: Chappell, Todd C., Nair, Nikhil U.
Format: Article
Language:English
Subjects:
Alcohols
Batch Cell Culture Techniques - methods
Bioconversion
Biofuels
Biomass
Biopolymers
Byproducts
Carbon
Carbon sources
Catabolism
Catabolite repression
Cell Communication - physiology
Cell Proliferation - physiology
Commercial species
Comparative analysis
Consortia
Design modifications
E coli
Escherichia coli - classification
Escherichia coli - physiology
Evolution & development
Galactose
Genetic Enhancement - methods
Hexose
Hexoses
Hexoses - metabolism
lignocellulosic biomass
Mannose
metabolic engineering
Metabolism
Microbial Consortia - physiology
microconsortium
Nutrient availability
Nutrient sources
Organic acids
Species Specificity
Sugar
Transport
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:ABSTRACT Escherichia coli is an important commercial species used for production of biofuels, biopolymers, organic acids, sugar alcohols, and natural compounds. Processed biomass and agroindustrial byproducts serve as low‐cost nutrient sources and contain a variety of hexoses available for bioconversion. However, metabolism of hexose mixtures by E. coli is inefficient due to carbon catabolite repression (CCR), where the transport and catabolic activity of one or more carbon sources is repressed and/or inhibited by the transport and catabolism of another carbon source. In this work, we developed a microconsortium of different E. coli strains, each engineered to preferentially catabolize a different hexose—glucose, galactose, or mannose. We modified the specificity and preference of carbon source using a combination of rational strain design and adaptive evolution. The modifications ultimately resulted in strains that preferentially catabolized their specified sugar. Finally, comparative analysis in galactose‐ and mannose‐rich sugar mixtures revealed that the consortium grew faster and to higher cell densities compared to the wild‐type strain. Biotechnol. Bioeng. 2017;114: 2309–2318. © 2017 Wiley Periodicals, Inc. Three strains of Escherichia coli were engineered to preferentially consume a different hexose‐glucose, galactose, or mannose‐ to overcome the native inefficiencies of catabolism of sugar mixtures. Strain engineering focused on enhancing growth on the intended substrate, reducing growth on alternative substrates, and reducing growth inhibition due to native regulatory pathways. When the engineered strains were grown together, the microconsortium grew faster, and to higher final cell densities than the wildtype strain in galactose‐ and mannose‐rich media.
ISSN:0006-3592
1097-0290
DOI:10.1002/bit.26351