Determination and modeling of yeast viability under stress conditions

Abstract

In this work the effect of the total pressure and the oxygen concentration in the gas phase on the growth and viability of Saccharomyces cerevisiae is studied. Cell viability was measured staining with methylene blue and assessed using digital image processing. A model that takes into account cell viability was developed and used for the correlation of the measured data. A dependence of the death rate, KD, with the total pressure and the oxygen concentration is proposed. Its behavior indicates that opposing effects between oxygen availability and baric and oxidative stresses are present on the system. It is shown that the proposed model can, with this extra parameter, successfully describe not only the traditional X-P-S evolution but also the ratio of viable cells with time.