Abstract

A total of one hundred and forty eight fungi isolated from both guinea corn (67) and rice (81) in a previous fungal and mycotoxin survey in Niger State, Nigeria, were tested for toxicity potential in white albino mice. Of all these, 64.2% were found to produce toxic metabolites that were lethal to mice and were mainly species ofAspergillus spp, Fusarium spp, Penicillium spp and Trichoderma spp. Others include Syncephalastrum spp, Alternaria spp, Phoma spp, Curvularia lunata, Colletotrichum spp., Geotrichum candidum and Helminthosporium spp, Cladosporium werneckil, and Mucor spp. and the bacteria Cryptococcus neoformis. The novel, most toxigenic fungi found contaminating these two staples were Fusarium verticillioides (Sacc.) Nirenberg, previously known as Fusarium moniliforme Sheldon (CABI Biosciences is IMI 392668).The extract of the fungus caused lethality to mice at 40 mg /kg b. wt. The health implications of these toxic microbes in our diets were discussed.

Key words: Guinea corn, rice, Nigeria, toxigenic fungi, mycotoxins.