The influence of the nitrogen source on the production of gibberellic acid in submerse cultivation ofGibberella fujikuroi

The influence of nitrogen sources on the level of gibberellic acid production was studied in submerse cultivation ofGibberella fujikuroi. The experiments were carried out with a single producer strain on media based on a previously elaborated medium containing saccharose and corn steep liquor. In addition to the favourable influence of certain organic nitrogenous substances, low initial pH values were also found to be of decisive importance; this was especially marked in medium containing yeast extract. Maximum production (400–500 μg./ml., cf. 190–240 μg./ml. on the original medium containing corn steep liquor) was obtained on suspension media containing peanut or soybean meal after 8–10 days' fermentation on a rotating shaker.