Fig. 4

Formate uptake and specific growth rates of ALE mutants. The specific growth rate (a) and formate uptake rate (b) for screened ALE evolved strains, growing in formate M9 minimal medium supplied with glycine at iOD of 0.7. Comparison of bacterial growth (c) and formate utilization (d) of wild-type (BL21) (black), EMK02 (yellow), EMK02A2 (blue), and EMK02A5 (red) in EMK medium at iOD of 0.1. The fractions of labeled amino acids in the EMK02A5 strain after 18-h cultivation with ¹³C-labeled formate at iOD of 0.1 (e). Ethanol production in different strains (f). Bars and dots represent titer and yield, respectively. The strains, EMK02etOH, EMK02A2etOH, and EMK02A5etOH, represented EMK02, EMK02A2, EMK02A5 harboring plasmid for overexpression of pyruvate decarboxylase and alcohol dehydrogenase for ethanol production, respectively. The detailed description of strains is given in Table 1