Search

Selenium (Se)-enriched yeast is a good nutritional source for human being. Kazachstania unispora (K. unispora) has shown the positive physiological functionality for human health, whose potential for Se enrichment, however, remains elusive. This study demonstrated the ability of K. unispora to convert inorganic Se to organic Se, and then comprehensively investigated the accumulation and metabolism of Se in K. unispora. The results indicated that K. unispora can effectively accumulate organic Se, of which 95% of absorbed Se was converted to organic forms. Among these organic Se, 46.17% of them was bound to protein and 16.78% was combined with polysaccharides. In addition, some of the organic Se was metabolized to selenomethionine (30.26%) and selenocystine (3.02%), during which four low-molecular weight selenometabolites were identified in K. unispora. These findings expand the scope of Se-enriched yeast species, and provide useful knowledge for further investigation of Se enrichment mechanism in K. unispora., Competing Interests: Declaration of competing interest The authors declare that they have no competing financial interests or personal relationships that could appear to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Conversion of inorganic selenium (Se) to its organic form by Saccharomyces cerevisiae (S. cerevisiae) has attracted significant attention, for organic Se has higher nutritional value with less negative effects. However, the mechanism of transformation and accumulation of organic Se at the metabolic level remains unclear. We investigated the metabolic response to sodium selenite supplementation in culture medium at 0, 5, 15, and 45 mg/L in two S. cerevisiae strains using an ultra-high performance liquid chromatography-high resolution mass spectrometry-based untargeted method. In total, 455 metabolites were detected, and a separation trend was clearly observed between Se-treated groups and controls. In depth, metabolic pathways involving amino acid, nucleotide metabolism and tricarboxylic acid cycle were significantly affected. Furthermore, high inorganic-Se supplementation effectively decreased the seleno-amino acid proportion in total Se, inhibited cell growth, and decreased glutathione levels. These results provide novel insights into the Se-enrichment process of S. cerevisiae. [Display omitted] • Chemical profile of sodium selenite-induced metabolic changes in Saccharomyces cerevisiae were analyzed. • In total, 97 and 117 differential metabolites were identified in Saccharomyces cerevisiae 1 and Saccharomyces cerevisiae 2, respectively. • Amino acid metabolism and the TCA cycle were prominently altered following sodium selenite-administration in Saccharomyces cerevisiae. • Exogenous glutathione increased the proportion of main seleno-amino acids in Saccharomyces cerevisiae. [ABSTRACT FROM AUTHOR]