Biogenic production of seleno-amino acids and seleno-nanoparticles by Saccharomyces boulardii

Selenium is an essential element for humans as it involves different metabolic mechanisms. More bioavailable and bioaccessible selenium species are produced by microorganisms bioconverting inorganic selenium into nanoparticles and seleno-amino acids, which are of technological and health interest. Therefore, the objective of this study was the biogenic production of seleno-amino acids and selenium nanoparticles by Saccharomyces boulardii. It was found that the minimum inhibitory concentration of selenite that allowed the viability of the yeast, the biotransformation of selenium, and the production of selenium nanoparticles was 74 ppm of sodium selenite in YPD broth. The yeast accumulated 3.4 mg/g of selenium after 9 h of fermentation in the YPD broth enriched with the calculated minimum inhibitory concentration of Na2SeO3. The presence of selenomethionine, selenocysteine, and selenium nanoparticles was verified through RP-HPLC and TEM analysis. The results demonstrated that the biogenic production of seleno-amino acids and seleno-nanoparticles by the probiotic yeast S. boulardii is possible. These compounds could have applications in the fields of food technology and medicine.