Mycobiota associated with maize grains in Uganda with special reference to aflatoxigenic Aspergilli

Maize grain samples bought from various markets and shops at different times in 5 districts of Uganda were investigated for contamination by fungi and aflatoxins. Using direct-plate method on dichloran rosebengal chloramphenicol agar medium at 25–27oC, thirty-seven species belonging to 21 genera were identified. The most frequent genera were, Aspergillus, Fusarium followed by Penicillium, Khuskia, Chaetomium and Cladosporium. A total of 2,879 fungal isolates, infesting 88.9% of the grains were recovered. Similarly, grains plated on Aspergillus flavus/parasiticus agar medium revealed that aflatoxigenic aspergilli positive on this medium infected 15.78% of the grains. Aflatoxin analysis of 10 maize grain samples (2 from each district) revealed that only 5 were naturally contaminated with aflatoxins in the range of 0–10 ppb. Key Words: fungi, maize, aflatoxigenic aspergilli, aflatoxins, Uganda. J. Trop. Microbiol Vol.2 2003: 17-2