Molecular identification of Aflatoxin B1 Aspergillus flavus in red, black and white pepper using PCR method

In this study, the prevalence of potential Aspergillus flavus producing aflatoxin B1 in three different types of pepper in Tehran grocery has been investigated. The experiments were performed on 90 samples of pepper, including 30 black pepper, 30 white pepper and 30 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 B1 was determined by specific primers to detect four genes from the aflatoxin B1 biosynthesis pathway. The results showed that the isolated fungi of red pepper samples consisted of 93.3% of Mucor species, 16.6% of Aspergillus niger and 3.3% of A. flavus. Also isolated fungi from black pepper samples were 36.6% of Mucor species, 33.3% of A. flavus and 30% of A. niger. The results on white pepper represented 40% of Mucor species, 36.6% of A. niger and 33.3% of A. flavus. The results of PCR showed that all A. flavus possesses nor-1, ver-1, omt-1 and afR1 genes and potentially produced aflatoxin B1. Only one sample of white pepper and one sample of black pepper lacked the omt-1 and aflR gene, which are therefore unable to produce aflatoxin. The presence of toxigenic fungi such as A. flavus in pepper can produce mycotoxin that affects the quality of pepper and causes human disorder.