LAUSR

 The effect of nanoparticles of biogenic metals (Fe, Mg, Zn, Mn) and their combinations on culturing the yeast Saccharomyces cerevisiae and on fermentation of sugar-containing raw materials into ethanol  have been investigated . The research involved the use of nanometal preparations obtained by volumetric electric-spark dispersion. It has proved effective to add nanozinc and a preparation containing nanomanganese and nanomagnesium, prior to yeast cultivation, to the growth media agar and wort agar in the concentrations 0.5 μg/cm3 and 11 μg/cm3 respectively. The experimental yeast grown on the medium containing these preparations increased the alcohol concentration in the distiller’s wort by 0.2%, whereas the content of unfermented carbohydrates remained within the prescribed limits 0.32–0.39 g/100 сm3. The yeast biomass increased by 1.2–1.4 times. Zinc and manganese/magnesium nanopreparations increased the maltase and invertase activities of the yeast under study by 40–25%. The nanoiron preparation contributed to inhibiting the fermentation activity of the yeast biomass. Biogenic metal nanocomplexes are used by yeast as an additional nutrient source. They form organometallic and intracomplex active compounds with yeast cell enzymes, primarily with hexokinase, aldolase, enolase. This intensifies synthesis of enzymes and increases their catalytic effect. The results obtained prove the effectiveness of biogenic metal nanopreparations as catalysts for biochemical transformations in a yeast cell. Using nanometals increases the productivity of bakery yeast, improves the technological process of alcoholic fermentation, and offers ample opportunity to increase the activity of enzyme preparations in the course of their production.