Engineering butanol‐tolerance in escherichia coli with artificial transcription factor libraries

Abstract Escherichia coli has been explored as a host for butanol production because of its many advantages such as a fast growth and easy genetic manipulation. Butanol toxicity, however, is a major concern in the biobutanol production with E. coli . In particular, E. coli growth is severely inhibited by butanol, being almost completely stopped by 1% (vol/vol) butanol. Here we developed a new method to increase the butanol‐tolerance of E. coli with artificial transcription factor (ATF) libraries which consist of zinc finger (ZF) DNA‐binding proteins and an E. coli cyclic AMP receptor protein (CRP). Using these ATFs, we selected a butanol‐tolerant E. coli which can tolerate up to 1.5% (vol/vol) butanol, with a concomitant increase in heat resistance. We also identified genes of E. coli that are associated with the butanol‐tolerance. These results show that E. coli can be engineered as a promising host for high‐yield butanol production. Biotechnol. Bioeng. 2011; 108:742–749. © 2010 Wiley Periodicals, Inc.