(A) Profiles of cell density (⋄), glucose (□), acetic acid (▵), succinic acid (○), and pyruvic acid (*) in two-stage cultivation of NZN111 in a 5-liter bioreactor. (B) Profiles of specific activities of ICL (⧫), MDH (▪), ME (▵), PCK (×), PPC (⋄) and PK (*).