Natamycin, also known as pimaricin, is a polyene macrolide antimycotic. It is used worldwide as a food preservative, primarily surface treatment of cheese and processed meat (e.g., dry sausages) by dipping, spraying, or in emulsion coatings. There are several advantages as a preservative, including broad activity spectrum, efficacy at low concentrations, lack of resistance, and activity over a wide pH range. Due to its low solubility, natamycin does not enter the food from its surface, and thus does not affect the organoleptic properties. It has no effect on bacteria, including those used as starter cultures or to promote ripening. It is chemically stable and has prolonged effectiveness. Moreover, it is easy to apply and has a proven safety record.
Natamycin is produced industrially by fermentation, using Streptomyces natalensis or Streptomyces gilvosporeus. The fermentation time occurs usually between 48 and 120 hours, dependant on the number of cells in the inoculum, composition of the medium, and the desired yield. Fermentation takes place at temperatures between 25 and 30°C and a pH range of 6 to 8. Natamycin is extracted from the culture broth using butanol, after acidification. Filtration is used to separate the biomass and other impurities from the natamycin product. Adjusting the pH, around neutral, leads to the precipitation of natamycin crystals. Almost pure white powder is obtained after a drying period.
Food and Beverage Industry
Natamycin possess antifungal activity to most mold and yeasts. High activity of natamycin allows most mold and yeasts to be inhibited with just small amount of natamycin, which makes natamycin the better alternative than sorbic acid. Besides that, natamycin has a wide active pH range and it does not change the flavor, appearance, texture and nutritional value of food. Hence natamycin is a good food preservative.
Natamycin is used as a preservative in pharmaceutical industry for tropical treatment like eye drops. It is used in cosmetic industry to preserve cosmetic products. It is also used to preserve crops, animal and poultry feed, agriculture in agriculture and poultry industry.