PURPOSE: To prepare the title antibiotic substance in high efficiency, useful as an anti- tomor agent, anti-fugnal agent, and anti-protozoal agent, by culturing antibiotic C-15003-producing microbials belinging to Nocardia genus in a medium containing isovaleroyl CoA precursor.
CONSTITUTION: Antibiotic substance C-15003P-4 of formula (R is isovaleroyl) is prepared by culturing microbials belonging to Nocardia genus and capable of producing antibiotic substance C-15003, e.g. Nocardia sp. C- 15003 (FERM-P No. 3992), in a medium containing 0.01-1.0 W/V%, pref. 0.1-0.5 W/V%, of an isovlaleroyl CoA precursor, e.g. α-ketoisocaprylic acid, leucine, etc., at 20W35°C. The temperature in the middle culturing stage is pref. 23W30°C, and the pH at the beginning of the culturing is pref. 6.5W7.5. The culturing is conducted for 2W10 days in case of aerated and agitated culturing.
HATANO KAZUNORI
ASAI MITSUKO
