Team:Tsinghua-E/Project

Overview

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

Darwinian evolution shows great power in creating incrediblebiological functionin amazing speed.Inspired by this, our team aimed atcreating novelfast and irrational microbial cell factory by simulating natural Darwinian evolution process. With tryptophan as target product, a novel tryptophan biosensorutilizing translating ribosome mechanismwas firstly developed as the foundation for tryptophan productivity and selection pressure switch module. We further constructedthis tryptophan overproduction selection gene circuit couplingwith in vivomutationmachine (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.