Synthetic biosensor accelerates evolution by rewiring carbon metabolism toward specific metabolite. Seok et al.
Proper carbon flux distribution between cell growth and production of a target compound is important for biochemical production because improper flux reallocation inhibits cell growth, thus adversely affecting production yield. Here, using a synthetic biosensor to couple production of a specific metabolite with cell growth, we spontaneously evolve cells under the selective condition toward the acquisition of genotypes that optimally reallocate cellular resources. Using 3-hydroxypropionic acid (3-HP) production from glycerol in Escherichia coli as a model system, we determine that mutations in the conserved regions of proteins involved in global transcriptional regulation alter the expression of several genes associated with central carbon metabolism. These changes rewire central carbon flux towards the 3-HP production pathway, increasing 3-HP yield and reducing acetate accumulation by alleviating overflow metabolism. Our study provides a new perspective on adaptive laboratory evolution (ALE) using synthetic biosensors, thereby supporting future efforts in metabolic pathway optimization. The original western blot image related to FigS3B demonstrates that CRP expression is reduced when its start codon is changed from ATG to TTG. The original western blot image related to FigS5A demonstrates that CRP mutation (T168P) changes the structure of CRP, causing difficulty of CRP detection by anti-CRP antibody. To solve this, synthetic 8-myc sequence is integrated downstream of the CRP and detected by anti-Myc antibody (the image related to FigS5D).