Influence of selenium yeast on the growth, selenium uptake and mineral composition of Coriolus versicolor mushroom.

The ability of Coriolus versicolor medicinal mushroom to grow and accumulate selenium during submerged cultivation in a selenium-fortified medium is examined in this paper. For selenium supplementation, commercial selenium yeast was used. Control, nonenriched sample and reference cultures cultivated in the medium enriched with commercial yeast Saccharomyces cerevisiae were also prepared. The mushroom demonstrated a high ability to accumulate selenium from the added source (around 970 and 1,300 µg/g of dry mycelium weight for samples enriched with selenium in a concentration of 10 and 20 mg Se/L, respectively). The addition of selenium significantly (p ≤ .05) increased the biomass yield, whereas the addition of nonenriched yeast had no significant (p ≤ .05) impact. Furthermore, regression analysis showed statistically significant (p ≤ .05) and positive correlations between the content of Se and Fe (r = .92), Se and Cu (r = .92), Se and Mn (r = .98), and Se and Sr (r = .96), suggesting that selenium incorporation was followed by incorporation of these elements, and led to mineral enrichment of the obtained mycelium. Methanol extracts prepared from mycelium biomass demonstrated a better inhibitory effect on Gram-positive bacterial strains with minimal inhibitory concentrations between <0.3125 and 40 mg/ml. The obtained results showed that selenium yeast could be used for obtaining a potential novel food supplement: mushroom biomass with high selenium content and enhanced mineral composition.