Natamycin Commercial Application

Natamycin is used for its antifungal properties, and is active over a wide pH range. It is active against Saccharomyces carlsbergensis from pH 4.0 to 10.0. It is effective against yeasts such as Candida albicans,Cryptococcus neoformans and Saccaromyces cerevisiae, and filamentous fungi such as Aspergillus flavus, Penicillium chrysogenum, Trichoderma spp., and Paecilomyces spp. as well as many others (Struyk, et al. 1957-1958).

Natamycin also demonstrates activity against parasitic protozoa, such as Trypanosoma cruzi (causal agent of Chagas disease) which, like many fungi, contain ergosterol in their cell membranes (Rolón, et al. 2006). While no longer considered within the fungi kingdom, oomycetes (such as the causal agent of Potato Late Blight, Phytophthora infestans) are notably insensitive to natamycin (Judelson 161 and Blanco 2005) (WHO 2001).

Commercial applications of natamycin in crop, livestock, and food production can be grouped into three basic categories: 
1. as an agricultural fungicide, either pre- or post-harvest, 
2. as a livestock medication,
3. as a preservative in processed foods.

Fungicide in agriculture
Natamycin is used to control fungal diseases in enclosed mushroom production facilities (EPA 2012a). EPA-approved labels include its use in the control of dry bubble disease, caused by Lecanicilium fungicola (also known as Verticillium fungicola), which affects commercially grown button mushrooms (Agaricus bisporus). The disease does not affect the vegetative portion of the fungus, but rather the edible mushroom, causing lesions and tissue disruption (such as stipe “blow-out” and other deformations). Natamycin may also be applied to mushrooms during production in an aqueous solution by hand or with an automatic watering system.

Natamycin is used as a post-harvest fungicide on fruit (including citrus, berries, pomes, stones, pineapples,melons, and bananas) to prevent spoilage caused by fungi such as Penicillium spp. and Geotricum spp. (Pace International 2016) (Huang, et al. 2016). Application methods vary depending on the label instructions and generally include first mixing with water or wax (see Combinations of the Substance for more information). Fruit application methods include dipping, drenching, spraying, and flooding (EPA 2017a).

Medical uses for livestock
Natamycin is used in animal health care applications as a veterinary drug. It has moderate activity against dermatophytes, yeasts and Aspergillus. It is used in some parts of the world to treat ringworm and candidosis in horses and cattle (Rochette, Engelen and Vanden Bossche 2003), and has also been used to treat nasal aspergillosis in horses. It is approved for use as an additive for feed and drinking water of broiler chickens (EPA 2012a).

Preservative in processed foods
Natamycin is commonly used in the U.S. to protect the surface of cheese and, in Europe and other countries, sausages against fungal development (Streekstra, Verkennis, et al. 2016). Natamycin is marketed for use in products such as cottage cheese, sour cream, yogurt, and packaged salad mixes (Siveele B.V.2009). It is used in beverage products to prevent mold and yeast (Keefe 2015).