Effect of overexpressing isocitrate lyase on succinate production in ldh-1 Corynebacterium glutamicum

Abstract:

Corynebacterium glutamicum SA001 is a mutant with lactate dehydrogenase (ldhA) deletion. In order to increase metabolic flux from isocitrate to succinate, and to improve the production of succinate under anaerobic conditions,we transducted the gene aceA coding isocitrate lyase (ICL) from Escherichia coli K12 into Corynebacterium glutamicum SA001 (SA001/pXMJ19-aceA). After 12 h aerobic induction by adding 0.8 mmol/L of IPTG, the recombinant strain was transferred to anaerobic fermentation for 16 h. Succinate reached 14.84 g/L, with a productivity of 0.83 g/(L·h). Compared to C. glutamicum SA001, the activity of ICL of the recombinant strain was increased 5.8-fold, and the succinate productivity was increased 48%. Overexpression of isocitrate lyase will increase the metabolic flux of glyoxylate bypass flowing to succinate.