Submitted to: International Journal of Food Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/12/2008
Publication Date: 4/15/2008
Citation: Atehnkeng, J., Ojiambo, P.S., Donner, M., Ikotun, T., Sikora, R.A., Cotty, P.J., Bandyopadhyay, R. 2008. Distribution and Toxigenicity of Aspergillus Species Isolated from Maize Kernels from Three Agro-ecological Zones in Nigeria. International Journal of Food Microbiology. 122:74-84. Interpretive Summary: The use of strains of Aspergillus flavus that do not produce aflatoxins to competitively exclude aflatoxin-producers has become widely accepted as a useful component of aflatoxin management programs. The current study sought to survey maize fields in Nigeria in order to identify atoxigenic strains of A. flavus that might be of superior value in mitigating contamination of maize. Several atoxigenic strains of potential value were identified. It was further determined that ecological zone influences the quantity of atoxigenic strains present. The study provides insights that may be of value in optimizing the use of atoxigenic strains for the prevention of aflatoxin contamination of maize.
Technical Abstract: Maize samples were collected during a survey in three agro-ecological zones in Nigeria to determine the distribution and aflatoxin-producing potential of members of Aspergillus section Flavi. Among Aspergillus, A. flavus was the most predominant and L-strains constituted > 90% of the species identified, while the frequency of the unnamed taxon SBG was < 3%. The incidence of atoxigenic strains of A. flavus was higher in all the districts surveyed except in the Ogbomosho and Mokwa districts in DS and SGS zones, respectively, where frequency of toxigenic strains were significantly (P < 0.05) higher than that of atoxigenic strains. When agro-ecological zones were compared, B-aflatoxins were significantly (P < 0.05) higher in SGS than in NGS, and intermediate in maize samples from the DS agro-ecological zone.