The synergistic effect of titanium dioxide nanoparticles and yeast isolated from fermented foods in reduction of aflatoxin B1.

The presence of aflatoxins in food products can lead to health risks in human societies. Therefore, in the present study, the effect of yeast strains isolated from fermented products and titanium dioxide nanoparticles (TiO 2 -NPs) was studied on aflatoxin reduction. Yeast strains were isolated from fermented products such as sweet fruits and dairy products and identified using biochemical, ascospore (testing by culture medium optimization V8 which is called V8NLF), and molecular methods. The probiotic activity of four selected yeasts was evaluated. Then, the effect of selected yeast isolates and TiO 2 -NPs on reducing aflatoxin B1 (AFB1) in the medium was studied by measuring AFB1 using ELISA and HPLC. The results of biochemical and molecular identification experiments indicate that the selected strain (Y1) is Saccharomyces cerevisiae . The selected strains showed good tolerance to different concentrations of bile salt, pH, and NaCl, indicating appropriate probiotic activity. It also showed antimicrobial activity against Escherichia coli , Shigella dysenteriae , and Salmonella typhimurium . Selected strain and TiO 2 -NPs showed AFB1 reducing activity in the medium and when combined, showed synergistic effects in reducing AFB1. TiO 2 -NPs in combination with selected yeast strains have a high ability to remove AFB1 from the medium and, therefore, can be used for future studies.