Metabolic engineering of Corynebacterium glutamicum to overproduce L-ornithine

Abstract

L-Ornithine is a non-essential amino acid with various applications in food industry. Weaim at high-titer production of L-ornithine by Corynebacterium glutamicum ATCC13032 through metabolic engineering. In addition to deletions of proB and argF, the argRgene encoding the regulatory repressor of L-arginine operon was also deleted toenhance the ornithine flux. Furthermore, plasmid-based overexpression of argCJBDgenes, changing the start codons of pgi and zwf and replacing the native promoter of thetkt operon with the strong sod promoter resulted in a titer of 51.5 g/L of L-ornithinewith productivity of 1.29 g/L/h under fed-batch conditions. [This work was supportedby the Technology Development Program to Solve Climate Changes on SystemsMetabolic Engineering for Biorefineries from the Ministry of Science, ICT and FuturePlanning (MSIP) through the National Research Foundation (NRF) of Korea.]