Comparative Study of Salt Tolerance in Saccharomyces cerevisiae and Pichia pastoris Yeast Strains

Abstract

The salt tolerance of both yeast strains have been compared in glucose media. Fermentation, cell numbers, cells viability , dry weight and glycerol determination was performed. The growth of cells was clearly reduced when the stress agent added at 5 hours fermentation. It was observed that the growth of cells was reduced with increased of concentration of stress agent from (0.5M to 1.5M). Pichia pastoris showed a better adaptation to high concentration of NaCl and sorbitol than Saccharomyces cerevisiae. Salt stress was accompanied by an increase in the intracellular level of glycerol. Saccharomyces cervisaie showed high glycerol production than Pichia pastoris strain. The cells viability remained at high levels under high salt stress even for more than 190 hours of fermentation.