Anaplerotic Reactions in Glutamic Acid Overproduction

For the production of glutamic acid, anaplerotic reactions are important to supply oxaloacetate to the TC A cycle for the latter to proceed. C. glutamicum possesses the following two anaplerotic reactions, catalyzed by phosphoenolpyruvate carboxylase (PPC) and pyruvate carboxylase (PC) [63,64]  

PC requires biotin for its activity as a coenzyme. In the presence of biotin, disruption of ppc, which encodes PPC, abolished glutamic acid production, but disruption of pyc, which encodes PC, did not affect glutamic acid production [65]. Moreover, under Tween 40 addition conditions, genetic and metabolic analyses indicted that the reaction catalyzed by PC was important for glutamic acid overproduction [12,66]. Metabolic analysis to investigate the roles of anaplerotic reactions in glutamic acid production is described in Section 11.4.2. 

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