Determination of vitality of yeast cells

In many cases, toxic effects of chemical or physical factors do not lead directly to cell death. Such factors may cause a number of morphological, intracellular, or metabolic alterations that will resultin the inability of a cell to divide, yet the cell itself maystill be alive.The method for assessing cell viability provide information only on alive and dead cells in thewhole population, but do not provide information about the number of vitality cells. In this aspect, cell vitality defining the physiological capabilities of the cell is a very important parameter. Measurement of cell vitality is advisable for conducting effective control of the fermentation process at a significant concentration of inhibitory substances that are produced during the process. It is very important for controlling the metabolic activity of yeast cells in fermentation in the brewing industry, in the production of bioethanol, in the bakery industry, etc. The Yeast Vitality Method is based on the determination of the enzyme esterase activity by means of the esterase substrate 5-carboxyfluorescein diacetate (CFDA). In parallel with this analysis, it is important to determine the total number of cells in the yeast suspension. This can be achieved by using the SOFIA GREEN fluorescent dye, which only stains the dead cells. To determine the total number of cells, it is necessary to treat the cells so that the membrane of the living cells becomes permeable to SOFIA GREEN. This is achieved by mixing the cell suspension with a lysis reagent for 10 minutes. The combination of these two analyzes results in an effective fermentation control and an increase in the yield and quality of the bioproduct obtained.