• Totop


Darwinian evolution for microbial cell factory:
in vivo evolution engineering towards tryptophan-overproduction superbug

Darwinian evolution shows great power in creating incredible biological function in amazing speed.Inspired by this, our team aimed at creating novel fast and irrational microbial cell factory by simulating natural Darwinian evolution process. With tryptophan as target product, a novel tryptophan biosensor utilizing translating ribosome mechanism was firstly developed as the foundation for tryptophan productivity and selection pressure switch module. We further constructed this tryptophan overproduction selection gene circuit coupling with in vivo mutation machine (mutator gene of mutD). By fine-tuning the selection conditions, our selection circuit showed good tryptophan dependent growth property, which provides the foundation for further evolution.As a preliminary result of this project, we successfully evolved an ancestor with zero productivity to a high-tryptophan producer only after several rounds of evolution.