Metabolic Engineering for Production of Biorenewable Fuels and Chemicals: Contributions of Synthetic Biology
Figure 3
Metabolic evolution for improving L-alanine production in E. coli [27]. 3(a) Redesigned metabolic pathway for L-alanine production: ATP production and cell growth is coupled to NADH oxidation and L-alanine production. 3(b) Directed evolution improves cell growth. Parental strain XZ112 reaches a maximum cell mass of 0.7 gL-1 after 48 hours of fermentation; evolved strain XZ113 attains 0.7 gL-1 after 24 hours and a maximum of 0.9 gL-1 after 48 hours; 3(c) metabolic evolution to improve cell growth also improves alanine production. Parental strain XZ112 produces 355 mM alanine after 72 hours of fermentation; evolved strain XZ113 produces 484 mM in 48 hours.
