抄録
Two auxotrophic mutants of Corynebacterium glutamicum were found to produce a large amount of L-proline in the culture medium. High concentration of MgSO4 or MnSO4 in the medium stimulated the L-proline production by an isoleucine auxotroph. Optimum concentration of L-isoleucine was 200 μg/ml, and the higher concentration of L-isoleucine reduced the L-proline production. The auxotroph produced 14.8mg/ml of L-proline when cultured in a medium containing 12% glucose, 1.7% NH4Cl, 0.6% MnSO4•7H2O, 0.06% MnSO4•4H2O and 200 μg/ml of L-isoleucine. The other mutant, whose growth responds to the bases of nucleic acids, produced 7 to 13mg/ml of L-proline in a cane molasses (15%, as glucose concentration)-medium containing 2% of the acid-hydrolyzate of soybean meal. The L-proline production by this mutant increased to a level of 27 to 31mg/ml when the growth was suppressed by the addition of 4% NH4Cl to the medium, or by the addition of 2mg/ml of polyoxy-ethylenestearylamine, a surfactant, to a culture at an appropriate stage of the fermentation.
