High production of L-ornithine by L-citrulline auxotroph of Brevibacterium ketoglutamicum: PART I: selection of stable mutant strains with less revertant formation

摘要

Overproduction of L-omithine by mutant strains isolated from Brevibacterium ketoglutamicum BK1046 was investigated. The strain was a L-citrulline auxotroph and exhibited culture instability during fermentation. Through a sequential screening effort, a highly stable strain with less revertant formation was finally selected and designated B. ketoglutamicum BK52 (KCTC 0141BP). It prouduced L-omithine at a high concentration (above 9 g/L) independent of subculture or cultivation time, and also had a very low tendency of revertant formation. In a long-term storage, this strain maintained its cell stability and productivity of L-omithine to a reasonable range.