Production of Fumonisin B Analogues and Related Compounds by Fusarium globosum, a Newly Described Species from Corn

Fusarium globosum Rheeder, Marasas et Nelson is a recently described species originally isolated from corn kernels harvested in the Transkei region of South Africa. On the basis of morphological criteria, F. globosum is closely related to other common fungal contaminants of corn, viz. F. moniliforme, F. proliferatum, and F. subglutinans, and accordingly it has been classified in the section Liseola. Species within the section Liseola have been reported to produce either the fumonisin B or moniliformin (MON) mycotoxins and, in some cases both. Seventeen isolates of F. globosum, cultured on corn, were screened for the production of fumonisins B1 (FB1), B2 (FB2), B3 (FB3), and MON. All isolates produced FB1 (range 5-325 μg/g), while 15 of 17 also produced FB2 (range 1-4 μg/g). For 14 of 17 isolates, the levels of FB3 produced (range 4-24 μg/g) exceeded those of the corresponding FB2 concentrations. None of the isolates produced detectable levels of MON (<1 μg/g). In addition, several isolates of F. globosum also produced two additional fumonisin-like compounds, the mass spectral evidence of which suggests that they may be isomers of FB1 and FB2 or FB3, respectively.Articl

Fusarium verticillioides strains isolated from corn feed: characterization by fumonisin production and RAPD fingerprinting

In this study a total of 16 Fusarium verticillioides strains isolated from corn feed samples were characterized by fumonisin (FB) production and random amplified polymorphic DNA (RAPD). All the strains produced FB1 and FB2 with levels ranging from 2.41 to 3996.36 µg/g, and from 1.18 to 1209.91 µg/g, respectively. From the 16 F. verticillioides strains, four were identified as low (3.59 to 1289.84 µg/g), eight as intermediate (>1289.84 to 3772.44 µg/g) and four strains as high (>3772.44 µg/g) fumonisin producers. From the total of 105 loci amplified, 60 (57.14%) were polymorphic. RAPD analysis showed very similar patterns among low, moderate and high fumonisin-producing strains. Although RAPD markers were capable of discriminating the different F. verticillioides strains, there was no clear association between these makers and fumonisin production.<br>Neste estudo, 16 cepas de F. verticillioides isoladas de amostras de ração de milho foram caracterizadas com base na produção de fumonisinas (FB) e em marcadores de polimorfismos de DNA amplificado ao acaso (RAPD). Todas as cepas produziram FB1 e FB2, com níveis variando, respectivamente, de 2,41 a 3996,36 µg/g e 1,18 a 1209,91 µg/g. De acordo com a produção de fumonisinas totais (FB1 + FB2) e a distribuição por análise de quartis, do total de 16 cepas de F. verticillioides, quatro foram identificadas como baixas produtoras de fumonisinas (3,59 a 1289,84 µg/g), oito como intermediárias (>1289,84 a 3772,44 µg/g) e quatro como altas produtoras de fumonisinas (>3772,44 µg/g). Os 10 primers utilizados amplificaram 105 locos, 60 (57,14%) dos quais foram polimórficos. As análises de RAPD mostraram padrões muito similares entre as cepas baixas, médias e altas produtoras de fumonisinas. Embora os marcadores RAPD tenham se mostrado capazes de discriminar as diferentes cepas de F. verticillioides, não foi detectada nenhuma associação entre estes marcadores e a produção de fumonisinas