In vitro ability of Saccharomyces cerevisiae and Lacticaseibacillus rhamnosus to bind aflatoxin B1 in phosphate-buffered saline solution

The utilization of strains of probiotic microorganisms has been demonstrated to be effective in the removal of mycotoxins. This study aimed to evaluate the in vitro adsorption capacity of aflatoxin B1, by Lacticaseibacillus rhamnosus and Saccharomyces cerevisiae, either alone and in combination, as well as the stability of the adsorbent/mycotoxin complex in each of the situations. Aflatoxin B1 working solutions for the assays were prepared in potassium phosphate buffer at pH 3.0 and pH 6.5, using aliquots of lactic acid bacteria and yeast culture containing a biomass of inactivated cells, either alone or in combination. After incubation, the solution was centrifuged, and the supernatant was separated for aflatoxin B1 quantification. The stability test of the aflatoxin B1 complex formed with all the mentioned treatments was carried out using the pellets obtained after centrifugation of the binding assays, performing multiple washes with phosphate buffer. The supernatant from each wash was analyzed for the amount of aflatoxin B1 released. The best aflatoxin B1 adsorption rate occurred with the use of lactic acid bacteria/S. cerevisae at both pH 3.0 (61.9%) and 6.5 (68.1%), followed by S. cerevisiae isolated at pH 3.0 (57.4%). Regarding the stability of the adsorbent/mycotoxin complex, they showed greater stability to S. cerevisae isolated at pH 3.0 (85.7%) and less stability to lactic acid bacteria at pH 3.0 (56.2%).