Fig. 3

Cellulosic glutamic acid fermentation by the engineered C. glutamicum XW6 strain in corn stover hydrolysate. Glutamic acid fermentation was carried out in 3-L fermentor (3BG-4, Baoxing Biotech Co., Shanghai, China) at 32 °C, 1.4 vvm of aeration and 600 rpm. No penicillin was added for induction. The fermentation was initiated by inoculating the seed culture in the 800-mL-corn stover hydrolysate-containing fermentor, and then 125 mL, 150 mL and 175 mL of fresh corn stover hydrolysate was fed into the fermentor at 30 h, 36 h and 40 h, respectively. Mean values are presented with error bars representing the minimum and maximum values