Copper-enriched biomass, method for the preparation thereof and pro-biotic, cosmetic, dietary and nutraceutic products comprising the same

The invention relates to a method for the preparation of a copper-enriched biomass, comprising, in a first step, culturing Saccharomyces cerevisiae yeast cells in a liquid nutrient medium comprising a carbon source, a nitrogen source, at least one amino acid and a copper salt, so as to obtain copper-enriched yeast biomass in the form of a Cu-GSH complex, wherein the intracellular content of Cu-GSH is higher than 1% dw and, in a second step, separating the copper-enriched yeast biomass from the nutrient liquid medium. Two strains of Saccharomyces cerevisiae are described, designated as SA 221 BM and SA 586 BM, respectively (accession numbers DSM 21530 and DSM 21531, deposited with the DSMZ on Jun. 6, 2008), which have the ability to accumulate particularly high levels of intracellular copper. Moreover, the invention relates to the copper-enriched yeast biomass obtainable by the method of the invention, which has an intracellular Cu-GSH content higher than 1% dw, and its use in cosmetic and probiotic products.