The contamination of cereals by mycotoxins, particularly zearalenone (ZEN), represents a global challenge for food safety and animal health. Brazil's diverse natural ecosystems also constitute an important reservoir of microorganisms with potential for biological control. This study evaluated the capacity of native Brazilian yeasts to adsorb ZEN using an in vitro model simulating pH conditions of the swine digestive system. Thirty-four yeast strains isolated from Brazilian biomes were initially screened for adsorption at pH 5.0, using 10 mg of biomass and a fixed ZEN concentration of 2.5 µg/mL. The effects of biomass amount (10, 20, and 30 mg) and pH variation (3-7) were subsequently evaluated using strains with the highest adsorption capacity. Adsorption isotherms were constructed with 30 mg biomass at ZEN concentrations ranging from 0.5 to 30 µg/mL under pH 3 and 6, and fitted to Hill, Langmuir, and Freundlich models. Adsorption increased with increasing biomass. The Hill model showed the best fit (R2 > 0.98), indicating positive cooperativity (n > 1) at all pH values, although the highest maximum adsorption capacity was observed at pH 3. Overall, Helenozyma melibiosica exhibited the greatest ZEN adsorption, while other strains also showed satisfactory performance.
Augusto et al. (Mon,) studied this question.