[1][4] Natamycin is used to treat fungal infections, including Candida, Aspergillus, Cephalosporium, Fusarium, and Penicillium.

[7] Natamycin is also known to diffuse slower and lesser into cheese when compared to sorbate, which could otherwise cause undesirable changes to the flavor.

[9] While not currently approved for use on meats in the United States, some countries allow natamycin to be applied to the surface of dry and fermented sausages to prevent mold growth on the casing.

[10] In 2009, the EFSA considered the proposed use levels of natamycin are safe if it is used for the surface treatment for these cheese and sausage types.

[12] In rats, the LD50 is ≥2300 mg/kg, and doses of 500 mg/kg/day over two years caused no detectable differences in survival rate, growth, or incidence of tumors.

[14] The EFSA has concluded that the use of natamycin as a food additive has no relevant risk for the development of resistant fungi.

[11] Natamycin inhibits the growth of fungi by specifically binding to ergosterol present in fungal cell membranes.

[15][16][17] Structurally-related antibiotics with similar binding properties are thought to produce hydrophilic channels that allow leakage of potassium and sodium ions from the cell.

[citation needed] Natamycin is produced as a secondary metabolite by some Streptomyces species: S. natalensis, S. lydicus, S. chattanoogensis and S.

As with other polyene antimycotics, the biosynthesis begins with a series of polyketide synthase modules, followed by additional enzymatic processes for oxidation and attachment of the substituents.

Pimaricin was later renamed after the World Health Organization (WHO) mandated that antibiotics produced by Streptomyces end in –mycin.