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Co‐utilization of hexoses by a microconsortium of sugar‐specific E. coli strains
Author(s) -
Chappell Todd C.,
Nair Nikhil U.
Publication year - 2017
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.26351
Subject(s) - catabolite repression , hexose , bioconversion , biochemistry , escherichia coli , sugar , galactose , chemistry , catabolism , mannose , metabolism , enzyme , fermentation , mutant , gene
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.