 Oxaloacetate decarboxylase activity in a given organism may be due to activity of malic enzyme, pyruvate kinase, malate dehydrogenase, pyruvate carboxylase and PEP carboxykinase or the activity of "real" oxaloacetate decarboxylases.The latter enzymes catalyze the irreversible decarboxylation of oxaloacetate and can be classified into (i) the divalent cation-dependent oxaloacetate decarboxylases and (ii) the membrane-bound sodium-dependent and biotin-containing oxaloacetate decarboxylases from enterobacteria.An oxaloacetate decarboxylase from the family of divalent cation dependent decarboxylases was isolated from Corynebacterium glutamicum in 1995 by Jetten et al.