Glycerol as a substrate for aerobic succinate production in minimal medium with Corynebacterium glutamicum

Corynebacterium glutamicum, an established microbial cell factory for the biotechnological production of amino acids, was recently genetically engineered for aerobic succinate production from glucose in minimal medium. In this work, the corresponding strains were transformed with plasmid pVWEx1-glpFKD coding for glycerol utilization genes from Escherichia coli. This plasmid had previously been shown to allow growth of C. glutamicum with glycerol as sole carbon source. The resulting strains were tested in minimal medium for aerobic succinate production from glycerol, which is a by-product in biodiesel synthesis. The best strain BL-1/pVWEx1-glpFKD formed 79 mM (9.3 g l(-1)) succinate from 375 mM glycerol, representing 42% of the maximal theoretical yield under aerobic conditions. A specific succinate production rate of 1.55 mmol g(-1) (cdw) h(-1) and a volumetric productivity of 3.59 mM h(-1) were obtained, the latter value representing the highest one currently described in literature. The results demonstrate that metabolically engineered strains of C. glutamicum are well suited for aerobic succinate production from glycerol.