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.

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The growth of bioethanol production in Ukraine is practical for both environmental and economic reasons. To reduce the cost of bioethanol production from sugar-containing raw materials, in particular, sugar beet molasses, it is effective to use high gravity wort and osmotolerant yeasts strains. Due to long exposure to high temperatures during sugar production and because of changes in the composition during storage, molasses accumulates compounds that adversely affect the function of yeast cells. For this type of raw material, a yeast strain should be found that will not only withstand high concentrations of sugars or the finished product, but will also be more resistant to inhibitors. The use of two industrial yeast strains (Deltaferm® AL-18 and Y 5007 (K-7)) for fermentation of high gravity molasses wort has been considered. It has been determined that sugar beet molasses, which is hard-to-ferment, can be used to produce ethanol from high gravity wort if some corrective measures are taken, in particular, resistant producer strains are used. It has been found that the yeast Deltaferm® AL-18 has a longer lag phase and consumes 50–60% of carbohydrates from the medium by 24 hours later than the yeast strain Y 5007 (K-7) does. It has been established how the parameters of the wash change depending on what yeast strains ferment high gravity wort based on hard-to-ferment molasses. It has been found that when using high gravity wort obtained from low-quality molasses, the yeast strain of foreign selective breeding does not allow achieving the calculated alcohol content in the fermented wash. According to the research results, under the same fermentation conditions, the distiller’s yeast strain Y 5007 (K-7) is more effective in fermenting high gravity wort based on hard-to-ferment molasses. Unlike it is with dry yeast, the industrial use of this strain according to the classical two-stream fermentation scheme does not require additional investments.