Fermentative Production of N^δ-Acetyl-L-ornithine with an Arginine and Pyrimidine Auxotroph of Paracolobactrum coliforme

Abstract

In the course of selecting a useful mutant strain for a fermentative production of L-valine, it was found that an arginine-pyrimidine auxotroph of Paracolobactrum coliforme accumulated N^δ-acetyl-L-ornithine (δ-AO) in the culture medium. The accumulation of it reached a level of 16mg/ml with medium containing 12.5% glucose, 2.2% (NH₄)₂SO₄, 0.5% peptone and 300μg/ml of uracil. The wild strain 775 also accumulated 1.4mg/ml of δ-AO in the medium supplemented with a high level (300μg/ml) of uracil when L-ornithine (10mg/ml) was added in the middle phase of fermentation. The mutant cells elongated under the condition with limited supply of uracil.
The mechanism of the accumulation of δ-AO was discussed from the information of relevant biosynthetic regulation in other organisms.