Figure 4.

Two-liquid phase fed-batch fermentation with E. coli BL21 (DE3) pJBEI-6410 in M9 minimal medium. Cell dry weight (CDW) (■), limonene concentrations (▲) in the organic phase, glycerol (▲), acetate (▼), and ammonium (■) concentrations were determined at regular intervals. The specific activities (●) were calculated for distinct time points throughout the fermentation time. The feed rate is displayed as well (dotted line). (A) and (B) display the initial fed-batch fermentation (D = 0.18 h⁻¹), whereas (C) and (D) display the optimized fed-batch fermentation with a lower feed rate (D = 0.15 h⁻¹) and additional trace element supply. The error bars for CDW relate to two independent measurements.