Comparative study regarding the ethanol resistance of some yeast strains isolated from Romanian vineyards

摘要

Recently there is increased interest in the identification and characterization of new valuable yeast strains to be used for the production of quality wines with specific traits. Such new strains need to be tested extensively regarding their behavior in relation to various factors. The paper presents results on the resistance to ethanol of ten yeast strains from the Saccharomyces genus selected from Romanian vineyards. The behavior of yeasts in the presence of ethanol was investigated using a calorimetric technique which allows for the determination of the growth rate as well as quantitative parameters that describe the inhibition of microbial growth by ethanol, such as the Minimum Inhibitory Concentration (MIC) and the concentration of ethanol that reduces microbial activity by 50%. It can also indicate if the inhibition mechanism is of a bactericidal or of a bacteriostatic nature. The technique allows for a comparison of the various yeast strains from the viewpoint of ethanol tolerance, with a view to selecting the most suitable strain for certain winemaking processes.