Glucosylation and Other Biotransformations of T-2 Toxin by Yeasts of the Trichomonascus Clade

Trichothecenes are sesquiterpenoid toxins produced byFusarium species. Since these mycotoxins are very stable, there is interest in microbial transformations that can remove toxins from contaminated grain or cereal products. Twenty-three yeast species assigned to theTrichomonascus clade (Saccharomycotina, Ascomycota), including fourTrichomonascus species and 19 anamorphic species presently classified inBlastobotrys , were tested for their ability to convert the trichothecene T-2 toxin to less-toxic products. These species gave three types of biotransformations: acetylation to 3-acetyl T-2 toxin, glycosylation to T-2 toxin 3-glucoside, and removal of the isovaleryl group to form neosolaniol. Some species gave more than one type of biotransformation. ThreeBlastobotrys species converted T-2 toxin into T-2 toxin 3-glucoside, a compound that has been identified as a masked mycotoxin inFusarium -infected grain. This is the first report of a microbial whole-cell method for producing trichothecene glycosides, and the potential large-scale availability of T-2 toxin 3-glucoside will facilitate toxicity testing and development of methods for detection of this compound in agricultural and other products.