Identification of Aspergillus flavus isolated from stored nuts in local markets of Baghdad (Iraq), and quantification of nuts aflatoxins using ELISA method

Stored nuts in the markets are naturally infected by different fungal species such as Aspergillus. The present study was carried out to evaluate the occurrence of toxicogenic A. flavus strains on nuts in Iraq. A total of ۱۱۲ nuts samples including hazelnuts, pistachio, peanut, and walnut with typical symptoms of dark and green discolored lesions on kernels were collected from various markets in Baghdad. Strains of Aspergillus spp. isolated from nuts seeds and their morphological characterization was based on MEA, PDA, and CYA. The identification of A. flavus isolates were confirmed molecularly using primers T۱/T۲. A total of ۲۵ fungal isolates belonged to Aspergillus species that were identified as A. niger (۱۰), A. flavus (۱۰), and A. japonicus (۵). In molecular analysis, sequences of partial β-tubulin gene were blasted in GenBank to confirm morphological identification of A. flavus isolates. Aflatoxins (AFs) contamination of ten infected samples with A. flavus was evaluated using ELISA method. Natural occurrence of AFs could be detected in all tested samples, ranging from ۶.۵۰–۷۴.۴۸ μg/kg. Our results completed the previously data about genetic potential of AFs production of A. flavus strains in Iraq and revealed in infected nuts also can be one of the great concern in Iraq.

Keywords:

Food Safety , Taxonomy , mycotoxins , β-tubulin gene , Elisa