Molecular Identification of Aflatoxin-Producing Aspergillus Species in Stored Groundnut Samples from Kebbi State Markets

Aflatoxin contamination of groundnuts poses severe health risks, including hepatocellular carcinoma and immune suppression, particularly in regions where groundnuts constitute a staple dietary component. This study investigated the presence of aflatoxin-producing Aspergillus species in stored groundnut samples from five markets across Kebbi State, Northwest Nigeria. A total of 100 groundnut samples were collected and subjected to fungal isolation on Aspergillus flavus and parasiticus agar (AFPA). Morphological identification was confirmed by molecular analysis targeting the beta-tubulin and calmodulin gene regions using species-specific PCR. Aflatoxin production capacity was assessed using high-performance thin-layer chromatography (HPTLC). Aspergillus flavus and A. parasiticus were identified in 72% and 18% of samples, respectively. Aflatoxin B1 levels exceeding the European Union maximum permissible limit of 2 ppb were recorded in 45% of samples, indicating significant contamination risks. The high contamination rate in Kebbi State markets is linked to inadequate post-harvest storage conditions and high ambient humidity. This study contributes baseline molecular data on mycotoxin-producing fungi in Northwest Nigeria and advocates for improved grain storage infrastructure. Keywords: aflatoxin, Aspergillus flavus, groundnut, molecular identification, Kebbi State.