Studies on the Bacterial Formation of Peptide Antibiotic, Colistin

Stimulatory Effect of Aspartic Acid on Colistin Production byBacillus polymyxa

“…In addition, the stimulatory effect was completely suppressed with a P0 4 3 -concentration more than 0.28%. These results indicated that only low concentration of P0 4 3 -was essential for the best production of colistin in Medium K + Asp together with the optimum concentration of NH 4 -N. The fact that addition of aspartic acid was ineffective on colistin production in Medium M was also found to be due to the highP0 4 3 -level in the medium.…”

“…In the case of 0.0035% P0 4 3 -, the increase of cell concentration by aspartic acid was very slight as compared with the remarkable improvement of colistin production. On the other hand, the addition of aspartic acid at 0.14% P0 4 3 -had a small effect on both cell concentration and colistin production.…”

“…In the case of 0.0035% P0 4 3 -, the increase of cell concentration by aspartic acid was very slight as compared with the remarkable improvement of colistin production. On the other hand, the addition of aspartic acid at 0.14% P0 4 3 -had a small effect on both cell concentration and colistin production. That is, aspartic acid provided a considerable difference in specific colistin production (colistin produced/maximum cell protein) between two P0 4 3 -levels.…”

“…On the other hand, the addition of aspartic acid at 0.14% P0 4 3 -had a small effect on both cell concentration and colistin production. That is, aspartic acid provided a considerable difference in specific colistin production (colistin produced/maximum cell protein) between two P0 4 3 -levels. When DAB was added to the media, the cell concentration was a little suppressed as compared with that in the reference medium (Table III).…”

“…As the result, 0.25% aspartic acid was added to Medium K (Medium K + Asp) in the following experiments. o corresponded to the P0 4 3 -concentration of Medium M, provided only a slight effect on colistin production with increased amounts of aspartic acid. In addition, the stimulatory effect was completely suppressed with a P0 4 3 -concentration more than 0.28%.…”