Fig. 5

Fed-batch culture of strain ZEFA (TE10) for free octanoic acid production. a Profile of fed-batch culture. b FFAs distribution in ZEFA (TE10) at the end of culture. Culture was initially performed in 300 mL M9+ 1.5% (wt/v) dextrose in 500-mL bioreactor. An additional 9 mL of fresh 50% (wt/v) glucose was added after 48 h, as indicated. Cultures were grown at 30 °C, and the pH was maintained at 7.0 using 2 M potassium hydroxide (KOH). Air flow rate was controlled at 0.3 L/min with 300 rpm as the initial stirring speed. The dissolved oxygen (DO) level was set over 40% and controlled by changing the stirring speed with the maximum of 600 rpm. Octanoic acid titers are the average of at least three replicates with error bars indicating one standard deviation. ZEFA, +fadZ ΔfadE ΔfumAC ΔackA