l-Valine accumulation during a representative batch cultivation of C. glutamicum ΔaceE(pJC4ilvBNCE) on CGXII medium initially containing glucose (4%), acetate (1%), and BHI (0.5%). ⋄, growth; ▪, glucose; □, acetate; ▵, pyruvate; •, l-valine. Three independent fermentations were performed, with all three showing comparable results.