Metabolic engineering of Corynebacterium glutamicum S9114 to enhance the production of L-ornithine driven by glucose and xylose

L-ornithine, an important amino acid, is widely used in food and medicine industries. L-ornithine production mainly relies on microbial fermentation, which may not meet the industrial requirement owing to the poor fermentation ability of available strains. Herein, mscCG2 deletion, CgS9114 12202 (gdh2) overexpression and rational modulation in tricarboxylic acid cycle was firstly demonstrated to increase L-ornithine production in engineered Corynebacterium glutamicum S9114. By further modulate glucose utility result in strain SO26 that produced 38.5 g/L or 43.6 g/L of L-ornithine in shake flask and fed-batch fermentation, respectively. This was 25% higher than that of the original strain (30.8 g/L) and exhibits highest titer reported in shake-flask. Moreover, the incorporation of xylose pathway in the engineered strain resulted in the highest L-ornithine production titer (18.9 g/L) and yield (0.40 g/g xylose) with xylose substrate. These results illustrate the tremendous potential of the engineered strain C. glutamicum S9114 in L-ornithine production.