Study of the biosynthesis of fumonisins B1, B2 and B3 by different strains of Fusarium moniliforme.

The relationship between fungal growth and the production of fumonisin on maize grain by 25 strains of Fusarium moniliforme of different origins has been investigated. Although sporulation was essentially the same for all the strains (about 10(8) propagules g-1 dry matter), ergosterol assays revealed marked variations in fungal biomass. All strains studied produced highly variable amounts of fumonisin B1, the highest levels being observed in strains of ergosterol content above 400 micrograms g-1. However, no correlation could be established between the synthesized biomass and the quantity of fumonisins produced. We verified that ergosterol is an indicator of mycelial growth, and therefore of the potential toxicity of the analysed grain.