Molecular identification of Aflatoxin B۱ Aspergillus flavus in red, black and white pepper using PCR method

Background/objective: In this study, the prevalence of potential Aspergillus flavus producing aflatoxin B۱ in three different types of pepper in Tehran grocery has been investigated. Materials and Methods: The experiments were performed on ۹۰ samples of pepper, including ۳۰ black pepper, ۳۰ white pepper and ۳۰ chilli peppers, and cultivated on Sabouraud dextrose agar. The isolation of the genus and species of fungi was performed by macroscopy and microscopy examination. In order to confirmation of A. flavus diagnosis, polymerase chain reaction (PCR) was performed using specific species primers. The ability to produce aflatoxin B۱ was determined by specific primers to detect four genes from the aflatoxin B۱ biosynthesis pathway. Results: The results showed that the isolated fungi of red pepper samples consisted of ۹۳.۳% of Mucor species, ۱۶.۶% of Aspergillus niger and ۳. ۳% of A. flavus. Also isolated fungi from black pepper samples were ۳۶.۶% of Mucor species, ۳۳.۳% of A. flavus and ۳۰% of A. niger. The results on white pepper represented ۴۰% of Mucor species, ۳۶.۶% of A. niger and ۳۳.۳% of A. flavus. The results of PCR showed that all A. flavus possesses nor-۱, ver-۱, omt-۱ and afR۱ genes and potentially produced aflatoxin B۱. Only one sample of white pepper and one sample of black pepper lacked the omt-۱ and aflR gene, which are therefore unable to produce aflatoxin. Conclusion: The presence of toxigenic fungi such as A. flavus in pepper can produce mycotoxin that affects the quality of pepper and causes human disorder.

Keywords:

Pepper , Aflatoxin B۱ , Aspergillus niger , Aspergillus flavus , PCR