Stimulation by L-Proline of 5′-Inosinic Acid Production by Mutants of Corynebacterium ammoniagenes

Abstract

The effects of amino acids on IMP production were examined with a mutant strain, KYI0895, derived from Corynebacterium ammoniagenes KY13374. L-Proline improved the productivity of IMP more than any other amino acid. The optimum concentration of L-proline for IMP production was 1-2% and the IMP productivity was about 70% more than that in the control medium. The effects of L-proline analogs on IMP production were also examined with the mutant KY10895. DL-3,4-Dehydroproline inhibited IMP production. Mutants resistant to growth inhibition by DL-3,4-dehydroproline were derived from strain KY10895. Among mutants thus obtained, strain H-7335 had the highest productivity. The intracellular concentrations of L-proline in strain H-7335 were higher than those of the parental strain, KY10895. These findings indicated that an increase in intracellular L-proline was linked with an increase of IMP productivity and strengthening the L-proline synthesis of a strain was an effective method for obtaining a hyper-producer of IMP. © 1991, Japan Society for Bioscience, Biotechnology, and Agrochemistry. All rights reserved.