Characterization of strains of <i>Aspergillus flavus</i> and <i>A. parasiticus</i> isolated from groundnut (<i>Arachis hypogea</i>), rice (<i>Oryza sativa</i>) and maize (<i>Zea mays</i>) in Senegal

Abstract

The contamination of certain food crop with aflatoxin poses a real public health problem for consumers and causes many market losses for exporters. Thus, several research works are oriented in the direction of developing methods to combat aflatoxinogenic fungus. This study aimed at identifying and characterizing strains of Aspergillus flavus and A. parasiticus on groundnut, maize and rice seeds grown or imported into Senegal. Four species (A. niger, A. tamarii, A. flavus and A. parasiticus) were isolated from the seeds with incidences ranging from 0 to 100% depending on the samples and their provenance. Six strains of A. flavus and 3 strains of A. parasiticus have been identified and characterized on CYA and G25N culture media. The characterization focused on the morphological characteristics (color and appearance, mycelial growth) of the colonies on the different culture media, and on some microscopic characteristics such as the density of sporulation (production of conidia) and the appearance of the conidiophore. Strains of A. flavus were more frequent on groundnuts and isolates with the same traits were also identified from rice and maize samples, hence the 3 strains of A. parasiticus were isolated.