Production of [14C]fumonisin B1 by Fusarium moniliforme MRC 826 in corn cultures

Abstract

Kinetics of growth and fumonisin production by Fusarium moniliforme MRC 826 in corn "patty" cultures were investigated, and a technique was developed for the production of ["4C]fumonisin B1 ([14C]FB,) by using L-[methyl-'4CJmethionine as the precursor. A significant (P < 0.01) correlation exists between fungal growth and FB1 (r = 0.89) and FB2 (r = 0.87) production in corn patties, beginning after 2 days and reaching the stationary phase after 14 days of incubation. [14C]FB, was produced by adding L-[methyl-14CJmethionine daily to cultures during the logarithmic phase of production. Incorporation of the isotope occurred at C-21 and C-22 of the fumonisin molecule and was enhanced in the presence of unlabeled L-methionine. Although the concentration of exogenous unlabeled methionine is critical for incorporation of the 14C label, optimum incorporation was achieved by adding 50 mg of unlabeled L-methionine and 200 ,uCi of L-[methyl-14Cjmethionine to a corn patty (30 g) over a period of 9 days, yielding [14CJFB1 with a specific activity of 36 ,uCi/mmol.

The Chemistry and Biological Activities of the Natural Products AAl-Toxin and the Fumonisins

“…All evidence so far obtained indicates that fumonisin is biosynthesized by a pathway analogous to sphingosine rather than the acetogenin pathway that is used in the biosynthesis of aflatoxins and many antibiotics from closely-related Streptomycetes and fungi. We have observed (15) that propionate, which is predicted to be a good precursor by the acetogenin pathway, is not an effective precursor of FB I, whereas methionine, which is predicted to be a good precursor in the sphingosine-type pathway, has been observed to be an excellent precursor of FB I in our studies (15) and the work of others (16,20,21,61). Similarly, we (15) and others (27) have observed that alanine is a good precursor of fumonisins.…”

Effect of water activity and temperature on growth and fumonisin B1and B2production by Fusarium proliferatum and F. moniliforme on maize grain

“…T h e changes in the ratios of FBI : FB, in relation to a, and temperature have not previously been examined. Naturally contaminated maize grain and animal feedstuffs were found to have ratios of 6 (Marasas et al 1988), while on milled moist maize culture the original fumonisin isolate F. moniliforme (MRC 826) was found to be approximately 1.9-2.1 (Alberts et al 1993 1958-1962. Doko, B. and Visconti, A.…”

Contamination of freshly harvested Bambara groundnut (Vigna subterranea) seed from Mpumalanga, South Africa, with mycotoxigenic fungi

“…One representative potential mycotoxin‐producing fungal species was randomly selected from the fungi isolated from each of the 12 samples (Table 5). For this analysis, fungal cultures were grown on maize patty media (J. F. Alberts, Gelderblom, Vleggaar, Marasas, & Rheeder, 1993). Yellow maize kernels were ground to a fine powder (20–40 g) using a sterile blender (Infinity Jug Blender, Russel Hobbs) which was used to prepare patty media in glass Pyrex Petri dishes (100 mm × 18 mm) by adding water (20–30 ml) followed by autoclaving for 1 hr at 121°C at 120 kPa on two consecutive days.…”

“…One representative potential mycotoxin-producing fungal species was randomly selected from the fungi isolated from each of the 12 samples (Table 5). For this analysis, fungal cultures were grown on maize patty media (J. F. Alberts, Gelderblom, Vleggaar, Marasas, & Rheeder, 1993).…”