PRODUCTION OF FUMONISIN-B ANALOGS AND RELATED-COMPOUNDS BY FUSARIUM-GLOBOSUM, A NEWLY DESCRIBED SPECIES FROM CORN

Fusarium globosum Rheeder, Marasas et Nelson is a recently described s pecies originally isolated from corn kernels harvested in the Transkei region of South Africa. On the basis of morphological criteria, F. gl obosum is closely related to other common fungal contaminants of corn, viz. F. moniliforme, F. proliferatum, and F. subglutinans, and accord ingly it has been classified in the section Liseola. Species within th e section Liseola have been reported to produce either the fumonisin B or moniliformin (MON) mycotoxins and, in some cases both. Seventeen i solates off. globosum, cultured on corn, were screened for the product ion of fumonisins B-1 (FB1), B-2 (FB2), B-3 (FB3), and MON. All isolat es produced FB1 (range 5-325 mu g/g), while 15 of 17 also produced FB2 (range 1-4 mu g/g). For 14 of 17 isolates, the levels of FB3 produced (range 4-24 mu g/g) exceeded those of the corresponding FB2 concentra tions. None of the isolates produced detectable levels of MON (< 1 mu g/g). In addition, several isolates of F. globosum also produced two a dditional fumonisin-like compounds, the mass spectral evidence of whic h suggests that they may be isomers of FB1 and FB2 or FB3, respectivel y.