Phosphotransferase system-mediated glucose uptake is repressed in phosphoglucoisomerase-deficient Corynebacterium glutamicum strains.

Corynebacterium glutamicum is particularly known for its industrial application in the production of amino acids. Amino acid overproduction comes along with a high NADPH demand, which is covered mainly by the oxidative part of the pentose phosphate pathway (PPP). In previous studies, the complete redirection of the carbon flux toward the PPP by chromosomal inactivation of the pgi gene, encoding the phosphoglucoisomerase, has been applied for the improvement of C.

The transcriptional regulators RamA and RamB are involved in the regulation of glycogen synthesis in Corynebacterium glutamicum.

When grown in glucose-, fructose- or sucrose-containing medium, the amino acid producer Corynebacterium glutamicum transiently accumulates large amounts of glycogen (up to 10% of its dry weight), whereas only a marginal amount of glycogen is formed during growth with acetate. This carbon-source-dependent regulation is at least partially due to transcriptional control of glgC, encoding ADP-glucose pyrophosphorylase, the first enzyme of glycogen synthesis from glucose-1-phosphate. Here, we have analysed a possible regulatory role for the transcriptional regulators RamA and RamB on glycogen content of the cells and on control of expression of glgC and of glgA, which encodes the second enzyme of glycogen synthesis, glycogen synthase.