Investigation of morphophysiological properties of yeast promising for ethanol production

Ethyl alcohol is a sought-after raw material in various sectors of the national economy, in particular in the food industry, medicine, and cosmetology. Recently, due to the need to reduce the burden on the environment, ethanol is used as a fuel, partially replacing gasoline and diesel fuel in internal combustion engines. In addition, for many countries that have a carbon deficit, replacing part of gasoline with ethanol is a solution to the problem of reducing fuel costs. Currently, 95% of ethanol produced from vegetable raw materials replaces 32% of gasoline. As a result of the work, it was found that to assess the effect of ethanol on the physiological activity of yeast, various control methods should be used. Thus, the absence of dead cells in the culture, as shown by the data obtained, cannot fully explain the metabolic activity of yeast in a medium with ethanol. Apparently, the intensity of ethanol stress is associated with complex, genetically determined processes, for example, activation of an extensive protein response and changes in the activity of ER enzymes. Comparison of the reproduction intensity of two strains of alcoholic yeast indicates the need to study their flocculation activity. In addition, when inoculating the medium, one must take into account the differences in cell size between different cultures, which can vary significantly. For example, yeast strain C16 is 33% larger than cells of strain C48. When comparatively assessing strains, only the quantitative determination of the concentration of cells in the inoculum should be used, and not the mass fraction of biomass in it.