Taxonomic Characterization and Secondary Metabolite Profiling of Aspergillus Section Aspergillus Contaminating Feeds and Feedstuffs

MARIANA GRECO, MINNA KEMPPAINEN, GRACIELA POSE, ALEJANDRO PARDO

TOXINS

MDPI

Lugar: Basel; Año: 2015 vol. 7 p. 3512 - 3537

2072-6651

Xerophilic fungal species of the genus Aspergillus are economically highly relevant due totheir ability to grow on low water activity substrates causing spoilage of storedgoods and animal feeds. These fungi can synthesize a variety of secondary metabolites,many of which show animal toxicity, creating a health risk for food production animalsand to humans as final consumers, respectively. Animal feeds used for rabbit, chinchillaand rainbow trout production in Argentina were analysed for the presence of xerophilicAspergillus section Aspergillus species. High isolation frequencies(>60%) were detected in all the studied rabbit and chinchilla feeds, whilethe rainbow trout feeds showed lower fungal charge (25%). These section Aspergillus contaminations comprised predominantlyfive taxa. Twenty isolates were subjected to taxonomic characterization using bothascospore SEM micromorphology and two independent DNA loci sequencing. The secondarymetabolite profiles of the isolates were determined qualitatively by HPLC-MS. Allthe isolates produced neoechinulin A, 17 isolates were positive for cladosporinand echinulin, and 18 were positive for neoechinulin B. Physcion andpreechinulin were detected in a minor proportion of the isolates. This is thefirst report describing the detailed species composition and the secondarymetabolite profiles of Aspergillussection Aspergillus contaminating animal feeds.