Present-day biotechnological processes are based on the use of the microorganisms producing active biological substances but the yeasts have a high production potential. The advantage of the yeasts use is, first of all, their rapid adaptability, since they grow up easily and have high productivity but their culture medium and cultivation conditions may be adjusted for the purpose of biosynthesis optimisation. They are resistant to alien microflora and do not pollute the environment. We shall mention the chemical substances acting as precursors or synthesis stimulators, within the range of the main factors regulating the biosynthesis capacity of bioactive principles in the yeasts. Special attention worldwide scientific research is directed to the use of metal nanoparticles which are the most promising structure of the 21st century, able to manipulate molecular processes, biochemical and cellular. This study elucidates the effect of TiO2 and Fe3O4 nanoparticles having the dimensions of 30 nm and the concentrations of 0.5, 1.0, 5.0, 10.0 and 15.0 mg/L of the culture medium, on protein accumulation on the base of the pigmented yeasts Rhodotorula Gracilis CNMN-Y-30. The results mark that the response reaction of the yeasts is manifested through favourable changes in the protein contents – by 16 to 30,9 % for TiO2 nanoparticles and from 14 to 23,8% for Fe3O4 (30 nm), if compared to the witness samples. The TiO2 nanoparticle concentrations of 0.5, 1.0 and 5.0 mg/L added to the nutritive medium initiate a clear accumulation of the protein contents in the yeast biomass, varying from 16 to 30,9% for TiO2 nanoparticles and from to 18,8 to 23,8% for Fe3O4. The TiO2 nanoparticle concentrations of 10.0 and 15.0 mg/L produce an increase by 23,8 to 25,9% in the protein contents in the biomass and Fe3O4 nanoparticles stimulates the synthesis protein with 14%. As a consequence, we may affirm that the protein biosynthesis process depends on the nanoparticle concentrations used, the type and chemical composition. Hence, the realised researches have shown that titan dioxide and iron oxide nanoparticles are the promising sources for stimulation of protein biosynthesis processes, thus representing and important factor for yeast cultivation Rhodotorula Gracilis CNMN-Y-30 and implementation of protein sources in various spheres: nutrition, pharmaceutics, cosmetology and medicine.