Addressing the Concern of Orange-Yellow Fungus Growth on Palm Kernel Cake: Safeguarding Dairy Cattle Diets for Mycotoxin-Producing Fungi

TL;DR

This study identifies non-toxic fungi in palm kernel cake used for cattle feed in Ecuador and suggests their potential use in preventing harmful fungal growth.

Contribution

The study identifies three non-mycotoxin-producing fungi in PKC and highlights their antifungal properties against harmful genera.

Findings

The yellow-orange fungus in PKC was identified as Candida ethanolica, a non-mycotoxin-producing yeast.

Two additional non-toxic fungi, Pichia kudriavzevii and Geotrichum candidum, were also identified.

These fungi show antifungal activity against Aspergillus and Penicillium, suggesting potential biocontrol applications.

Abstract

Palm kernel cake (PKC), a byproduct of palm oil extraction, serves an important role in Ecuador’s animal feed industry. The emergence of yellow-orange fungal growth in PKC on some cattle farms in Ecuador sparked concerns within the cattle industry regarding a potential mycotoxin-producing fungus on this substrate. Due to the limited availability of analytical chemistry techniques in Ecuador for mycotoxin detection, we chose to isolate and identify the fungus to determine its association with mycotoxin-producing genera. Through molecular identification via ITS region sequencing, we identified the yellow-orange fungus as the yeast Candida ethanolica. Furthermore, we isolated two other fungi—the yeast Pichia kudriavzevii, and the fungus Geotrichum candidum. Molecular identification confirmed that all three species are not classified as mycotoxin-producing fungi but in contrast, the literature indicates that all three have demonstrated antifungal activity against Aspergillus and Penicillium species, genera associated with mycotoxin production. This suggests their potential use in biocontrol to counter the colonization of harmful fungi. We discuss preventive measures against the fungal invasion of PKC and emphasize the importance of promptly identifying fungi on this substrate. Rapid recognition of mycotoxin-producing and pathogenic genera holds the promise of mitigating cattle intoxication and the dissemination of mycotoxins throughout the food chain.

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