Abstract
Xerophilic fungal species of the genus Aspergillus are economically highly relevant due to their ability to grow on low water activity substrates causing spoilage of stored goods 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 animals and to humans as final consumers, respectively. Animal feeds used for rabbit, chinchilla and rainbow trout production in Argentina were analysed for the presence of xerophilic Aspergillus section Aspergillus species. High isolation frequencies (>60%) were detected in all the studied rabbit and chinchilla feeds, while the rainbow trout feeds showed lower fungal charge (25%). These section Aspergillus contaminations comprised predominantly five taxa. Twenty isolates were subjected to taxonomic characterization using both ascospore SEM micromorphology and two independent DNA loci sequencing. The secondary metabolite profiles of the isolates were determined qualitatively by HPLC-MS. All the isolates produced neoechinulin A, 17 isolates were positive for cladosporin and echinulin, and 18 were positive for neoechinulin B. Physcion and preechinulin were detected in a minor proportion of the isolates. This is the first report describing the detailed species composition and the secondary metabolite profiles of Aspergillus section Aspergillus contaminating animal feeds.
Highlights
Fungal contamination of foods and feeds causes negative effects on the quality of the products mainly reducing their nutritional and organoleptic properties and lead to important annual economic losses worldwide [1,2,3,4]
The presence of xerophilic fungi of Aspergillus section Aspergillus was analysed in commercial and non-commercial producer assembled formulations of rabbit, chinchilla, and rainbow trout feeds used in animal production in Argentina
The presence of xerophilic fungi was tested in a wide variety of primary raw materials used either for direct feeding or for preparation of homemade animal feed mixes by the producers
Summary
Fungal contamination of foods and feeds causes negative effects on the quality of the products mainly reducing their nutritional and organoleptic properties and lead to important annual economic losses worldwide [1,2,3,4]. Because the section Aspergillus fungi can produce multiple secondary metabolites with adverse effects on animal health and reports of even more hazardous mycotoxins production exist, these high contamination levels are suggesting that both a direct and an indirect risk for animal and human health could be linked to the use of these contaminated animal feeds. This makes the further studies on the degree of xerophilic fungal contamination, the detailed species composition identification and especially, the toxicological characterization of the isolates obtained from animal feeds very valuable. To avoid any confusion to the readers, the five Aspergillus section Aspergillus species most relevant to this study and supported by the recent taxon revision by Hubka and colleagues [42] are presented in Table 1, together with their corresponding former genus Eurotium names
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
