An efficient succinic acid production process in a metabolically engineered Corynebacterium glutamicum strain. A Corynebacterium glutamicum strain (DeltaldhA-pCRA717) that overexpresses the pyc gene encoding pyruvate carboxylase while simultaneously exhibiting a disrupted ldhA gene encoding L-lactate dehydrogenase was investigated in detail for succinic acid(cas:110-15-6) production.

Succinic acid(cas:110-15-6) was shown to be efficiently produced at high-cell density under oxygen deprivation with intermittent addition of sodium bicarbonate and glucose. Succinic acid(cas:110-15-6) concentration reached 1.24 M (146 g l(-1)) within 46 h. The yields of succinic acid(cas:110-15-6) and acetic acid from glucose were 1.40 mol mol(-1) (0.92 g g(-1)) and 0.29 mol mol(-1) (0.10 g g(-1)), respectively.

The succinic acid(cas:110-15-6) production rate and yield depended on medium bicarbonate concentration rather than glucose concentration. Consumption of bicarbonate accompanied with succinic acid(cas:110-15-6) production implied that added bicarbonate was used for succinic acid(cas:110-15-6) synthesis.