Improved succinate production in Corynebacterium glutamicum by engineering glyoxylate pathway and succinate export system.

A dual route for anaerobic succinate production was engineered into Corynebacterium glutamicum. The glyoxylate pathway was reconstructed by overexpressing isocitrate lyase, malate synthase and citrate synthase. The engineered strain produced succinate with a yield of 1.34 mol (mol glucose)(-1). Further overexpression of succinate exporter, SucE, increased succinate yield to 1.43 mol (mol glucose)(-1). Metabolic flux analysis revealed that the glyoxylate pathway was further activated by engineering succinate export system. Using an anaerobic fed-batch fermentation process, the final strain produced 926 mM succinate (= 109 g l(-1)) with an overall volumetric productivity of 9.4 mM h(-1) and an average yield of 1.32 mol (mol glucose)(-1).