Influence of water activity on the production of T-2 Toxin byFusarium sporotrichioides.

The production of T-2 Toxin by two strains ofFusarium sporotrichioides at high (0.995), medium (0.970) and low (0.945) water activity (aw) was investigated. The organisms were incubated in an optimal liquid base medium (Wort broth) adjusted to the different aw values. With decreasing aw the amount of T-2 Toxin in the culture supernatants fell drastically. Comparing cultures that had reached almost equal mycelial dry weights, those of low aw had T-2 Toxin levels 10 to 100 times lower than those of high aw. This effect was observed using both glycerol or sodium chloride as humectants.