This bachelor’s thesis examines the cultivation of five yeast strains using plant peptones as a nitrogen source, with a view to potentially utilizing their biomass in cosmetic products. The strains involved are Saccharomyces cerevisiae, Yarrowia lipolytica, Metschnikowia reukaufii, Phaffia rhodozyma, and Komagataella pastoris, cultured on potato, soybean, wheat, and pea peptone. For comparison, cultures were also performed in media containing animal peptones (meat and casein peptone). The theoretical section addresses sustainable cosmetics, the use of fermentation in the cosmetics industry, the characterization of selected yeasts, their regulatory status, safety, and the permitted amount of yeast in cosmetic products. In the experimental section, selected strains were cultured on plant and animal peptones in a production medium containing glucose, selected peptones, sodium chloride, magnesium sulfate heptahydrate, and potassium dihydrogen phosphate. Biomass yield, β-glucan content using a commercial kit, protein content according to the Hartree-Lowry method, and metabolites of the Phaffia rhodozyma strain using high-performance liquid chromatography were determined. Furthermore, the strains were cultured under limiting conditions using only potato peptone. The first limitation was nitrogen, but with increased carbon, to promote lipid accumulation. The second was phosphorus limitation, where the phosphorus component was omitted from the culture for 24 hours and subsequently added at an elevated concentration. For this biomass, the biomass yield and metabolites of the Phaffia rhodozyma strain were determined in comparison with cultivation under non-limiting conditions. The biochemical profile of the biomass of all cultured yeasts was analyzed using infrared spectroscopy. The highest yield was observed for the Yarrowia lipolytica strain, regardless of the peptone used. The metabolites of the Phaffia rhodozyma strain did not show significant differences depending on the peptone used. In terms of peptone, the yeasts performed best on potato peptone. Komagataella pastoris had the highest β-glucan content on meat peptone, and Yarrowia lipolytica had the highest protein content on potato peptone. FTIR-ATR analysis did not reveal a significant effect of the peptone source on the biochemical profile of the biomass, but it did show that, under nitrogen-limiting stress conditions, lipids accumulate in all strains except Metschnikowia reukaufii. Phosphorus limitation revealed that polyphosphates accumulate significantly in the Saccharomyces cerevisiae and Komagataella pastoris strains.