earticle

영어

Escherichia coli has been explored as a host for an alternative biofuel butanol production because of its many advantages such as a fast growth and easy genetic manipulation. However, the low butanol-tolerance of E. coli (<1% [vol/vol] butanol) is a major obstacle for their exploitation in the butanol production. Here we developed a new method to increase the butanol-tolerance of E. coli by 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 could select a butanol-tolerant E. coli which can tolerate up to 2.5% (v/v) butanol and then introduced a butanol synthesis pathway into the selected butanol-tolerant E. coli. The resulting butanol-producing strain E. coli showed increase in butanol production by ~20% compared to a wild-type E. coli strain engineered with the same ATFs described above. As an alternative, the butanol tolerance of E. coli is also improved by regulating the fatty acid composition of the plasma membrane. In addition, DNA scaffold approach is being explored to further increase the butanol production. The strategies described herein will open up an unexplored frontier for high-yield butanol production in E. coli.