Fig. 4

Illustration of Corynebacterium glutamicum engineering methods for efficient cellulosic glutamic acid production. The left chart indicates the overall metabolic pathway modifications of C. glutamicum; the right chart indicates the elevations of glutamic acid accumulation corresponding to each step of metabolic engineering modification. PEP phosphoenolpyruvate, Pyr pyruvate, AcCoA acetyl-CoA, Cit citrate, Icit isocitrate, 2-KG α-oxoglutarate; Suc succinate, Fum fumarate, Mal malate, OAA oxaloacetate, Gly glyoxylate, AccBC acetyl-CoA carboxylase α-subunit, AccD1 acetyl-CoA carboxylase β-subunit. All the fermentations were 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. Mean values are presented with error bars representing the minimum and maximum values