Isolation of acetyl T-2 toxin from Fusarium poae

Detection of T-2 toxin in Fusarium sporotrichioides-infected corn by enzyme-linked immunosorbent assay

A competitive enzyme-linked immunosorbent assay was used to screen for T-2 toxin in Fusarium sporotrichioides -infected corn. The assay detected T-2 toxin in diluted methanol extracts of corn samples at concentrations of 0.05 ng/ml. In infected corn samples, enzyme-linked immunosorbent assay and gas-liquid chromatography estimations of T-2 toxin concentrations were similar.

Swine refusal factors elaborated by Fusarium strains and identified as trichothecenes

Fusarium poae (Peck) Wollenw. NRRL 3287, F. nivale (Fr.) Ces. NRRL 3289, and F. moniliforme Sheldon NRRL 3197, each grown on cracked corn (13 days at 28 degrees C), produced refusal factors in pig bioassays. Substantial quantities of trichothecenes were detected in the refused corn: T-2 toxin (30 micrograms/g) was detected in corn fermented with the F. poae strain; the level of vomitoxin (1 microgram/g) in corn cultured with F. nivale did not account for the 48% refusal response in the pigs tested. The F. moniliforme concomitantly produced T-2 toxin (33 micrograms/g) and vomitoxin (1.5 micrograms/g). This strain's taxonomic position was reexamined, and it is shown to be a cultural variant of the species F. tricinctum (Cda.) Sacc.

Microbial acetyl conjugation of T-2 toxin and its derivatives

The acetyl conjugation of T-2 toxin and its derivatives, the 12,13-epoxytrichothecene mycotoxins, was studied by using mycelia of trichothecene-producing strains of Fusarium graminearum, F. nivale, Calonectria nivalis, and F. sporotrichoides, T-2 toxin was efficiently converted into acetyl T-2 toxin by all strains except a T-2 toxin-producing strain of F. sporotrichoides, which hydrolyzed the substrate to HT-2-toxin and neosolaniol. HT-2 toxin was conjugated to 3-acetyl HT-2 toxin as an only product by mycelia of F. graminearum and C. nivalis, but was also resistant to conjugation by both F. nivale and F. sporotrichoides. Neosolaniol was also biotransformed selectively into 3-acetyl neosolaniol by F. graminearum. However, 3-acetyl HT-2 toxin was not acetylated by any of the strains under the conditions employed, but was hydrolyzed to HT-2 toxin by F. graminearum and F. nivale. This is the first report on the biological 3 alpha-O-acetyl conjugation of T-2 toxin and its derivatives.

Production of refusal factors by Fusarium strains on grains

Corn fermented with strains of Fusarium culmorum NRRL 3288, F. poae NRRL 3287, F. moniliforme NRRL 3197, and F. nivale NRRL 3289 at 28 degrees C for 13 days was refused when fed to 30- to 60-pound (about 13.6- to 27.2-kg) swine. Analyses of the refused corn for trichothecenes (T-2, HT-2, acetyl T-2, fusarenon-X, and vomitoxin) showed that only the corn fermented with F. culmorum contained vomitoxin. None of these five trichothecenes could be detected in the other refused corn.F. culmorum grown on rice at 28 degrees C for 13 days also produced vomitoxin.