Fermentation process for producing natamycin with additional carbon and nitrogen

In a method for producing natamycin, comprising, in order, the steps of:

• (a) introducing an inoculum of a natamycin producing Streptomyces strain to a fermentation medium to produce a fermentation broth comprising the fermentation medium and inoculum;
• and
• (b) producing natamycin by culturing the Streptomyces strain in the fermentation broth;
• the improvement comprising:
• (1) providing at least about 15 g/L of a protein nitrogen source to the fermentation medium, wherein the protein nitrogen source comprises a non-yeast protein component and a yeast protein component, and the ratio of non-yeast protein component to yeast protein component being from about 3:1 to 9:1, based on the protein content of the source;
• (2) providing a carbon source to the fermentation medium at from about 80 g/L to 250 g/L, wherein the carbon source addition is carried out during step (b) so as to maintain a concentration of carbon source of from about 5 g/L to 30 g/L;
• (3) continuing the fermentation until the fermentation broth comprises at least 5 g/L natamycin;
• and
• (4) removing a portion of said fermentation broth and replacing said removed portion by adding a substantially equivalent amount of fresh fermentation medium.