Abstract
The effect of osmotic strength on 5'-inosinic add (IMP) fermentation was examined with a mutant, Corynebacterium ammoniagenes KY10895. The growth of KY10895 was inhibited by increased osmotic strength in the medium, but the specific IMP production (IMP produced/cell density) was promoted. The concentration of L-proline increased greatly under osmotic stress. Mutants resistant to growth inhibition by osmotic strength were derived from KY10895. Strain H-4415 had the highest IMP productivity. The intracellular concentration of L-proline in strain H-4415 was higher than in the parental strain. The addition of an osmoprotectant, betaine, in the production medium did not increase IMP production. These results suggested that the derivation of an osmotolerant stain is an effective method to obtain a hyperproducer of IMP, and that an increase in intracellular L-proline is related to increased IMP production.
