Studies on an Antibiotic Substance Oryzacidin, Produced by Asp. oryzae

We produced Oryzacidin by tank fermentation of the strain Asp. oryzae sp. A-33, and pursued the relation between Oryzacidin production and chemical changes of the media. The results are as follows. In the fermentation, pH of the media decreases with the consumption of sugar and N-substances by the organism, in the media, then increases sharply when sugar is almost lost and only N-substances are digested. At the time just before pH reaches to 7.0, the produc-tion of Oryzacidin become maximum. The production of Oryzacidin by tank fermentation is about double as compared with surface culture.