The capacity of orotic acid production in pyrimidinedeficient mutants ofBrevibacterium ammoniagenes

Eight uracil-dependent mutants ofBrevibacterium ammoniagenes CCEB 364 and three mutants ofCorynebacterium sp. 9366 were checked for the production of precursors of nucleic acids. Four of the strains liberated into the medium a substantial amount of orotic acid. The production of orotic acid by a mutant ofBrevibacterium ammoniagenes (1043) was examined on mineral media containing varying amounts of glucose in the presence of uracil. The optimum concentration of glucose for the production of orotic acid was found to be 5–8%. On media to which natural substrates were added the orotic acid production increased substantially. The maximum production (6.5 g orotic acid/liter) was reached in a medium containing 0.5% yeast extract and 5% glucose; addition of uracil to this medium had no effect on the production. The maximum rate of production occurred between 24 and 72 h of fermentation. After this period the concentration of orotic acid in the medium decreases.