Устойчивость дрожжей Saccharomyces cerevisiae к экстремальным условиям

Abstract

The resistance of the yeast Saccharomyces cerevisiae DAW-3а and Y-503 to the conditions of extreme values of pH, NaCl, temperature has been studied. Under different cultivation modes, the rounded shape of DAW-3a cells is pre-served and this parameter Y-503 changes. Under conditions of different pH values and 30°C, the maximum sizes of cells and giant colonies of the polyploid Y-503 strain were found in comparison with the haploid DAW-3a; at 37°C, the advantage of Y-503 was not observed and the colony sizes of both strains were practically the same. The reaction of the strains to critical concentrations of NaCl in the medium was identical: a decrease in the size of cells and colonies was found; change in the shape, surface, color and structure of colonies. Under conditions of the simultaneous influence of an elevated temperature of 37°C, a wide range of pH and 5 % NaCl, the cell size decreased slightly; under neutral and alkaline conditions of cultivation, a slightly greater tolerance of yeast to salt stress was established; a decrease in the size of giant colonies was found, while the maximum size of the studied strains was noted at pH 11.0, the minimum at pH 3.0. The study of the tolerance of the yeast S. cerevisiae DAW-3a and Y-503 to extreme factors is of particular interest in connection with the possibility of using stress-resistant strains in biotechnological processes.