Fig. 7
From: Self-regulated 1-butanol production in Escherichia coli based on the endogenous fermentative control
1-Butanol production efficiency affected by the timing of anaerobic switch. Strain ΔldhA ΔfrdBC ΔadhE Δpta transformed with the best combination (FRE ackA ::atoB-adhE2-crt-hbd, FRE adhE ::ter, FRE adhE ::fdh) was used in this study. Cells were grown in TB medium aerobically then switch to anaerobic condition at various cell densities as indicated on the x-axis. The label “Conc” describes the condition where cells were first grown anaerobically overnight in TB to induce enzyme expression and then concentrated to an OD600 around 9 for subsequent 1-butanol production under anaerobic condition. Adjustment of culture pH and feeding of glucose was performed every 24 h. The figure legend (h) indicates time since anaerobic switch