Identification and characterization of aflatoxigenic Aspergillus Section Flavi by polyphase approach from Brazil nuts produced in agroforesty production system

Brazil nut is an Amazonian raw material with a fundamental role in the socioeconomic organization of the extractive areas of the Legal Amazon Brazil's largest socio-geographical division, composed of nine states are part of the Amazon basin. However, due to the precarious conditions of storage and processing, the nut is frequently subjected to contamination by aflatoxigenic fungi. These fungal species have high similarity, which makes it difficult to identify them only by traditional methods. This research had as objective the identification of a species of Aspergillus Flavi isolated from Brazil nut samples, through the polyphase approach. To identify the fungal isolate, macromorphological and micromorphological characterization techniques by microcultive in a slide  were used; The molecular identification followed by sequencing compared the nucleotide sequences with the GenBank database, the aflatoxigenic  potential of the strain was evaluated by HPLC. According to the results, the macromorphological and micromorphological analysis showed color characteristics and reproductive structures typical of the genus Aspergillus and the Flavi section. However, only from the results of molecular identification in which the strain showed 100% similarity with Aspergillus nomius and the metabolic production profile in which the species was producing the 4 types of aflatoxins (AFG2= 1177,23, AFG1 = 2458, 90, AFB2 = 860,23, AFB1 = 2370,06) it was possible to carry out the correct identification of the fungus as Aspergillus nomius. The combination of different techniques for identification of the strain Aspergillus section Flavi allowed a more accurate characterization.  The identification of strain as Aspergillus nomius with aflatoxigenic potential in Brazil nuts confirms the affinity of these microorganisms for this substrate.