Influence of thermal and osmotic stresses on the viability of the yeast Saccharomyces cerevisiae

doi:10.1016/S0168-1605(00)00203-8

International Journal of Food Microbiology

Volume 55, Issues 1–3, 10 April 2000, Pages 275-279

https://doi.org/10.1016/S0168-1605(00)00203-8 Get rights and content

Abstract

This work studies the effect of thermal and dehydration kinetics on the viability of Saccharomyces cerevisiae. The influence of the rate of temperature (T) and osmotic pressure (Π) increases are first investigated. Results showed that yeast viability is preserved by slow variations of temperature or osmotic pressure in a precise range of T or Π. The influence of a previous thermal stress on the resistance to a hyperosmotic stress is also studied. Temperatures equal to or lower than 10°C allowed the preservation of viability after an osmotic stress whereas temperatures above 10°C did not preserve yeast survival.

Introduction

The preservation of biological systems is currently achieved by decreasing the water content and hence the water activity of the medium. The classical dehydration processes are: freeze-drying, spray-drying and thermal drying. These processes change the physical state of water by the variation of temperature or pressure or by the combined action of these parameters. Therefore, cells dehydrated using such methods are subjected to a simultaneous variation of temperature and water activity.

We first carried out experiments where the effects of water activity and temperature variation rates on cell survival were separately studied. For this purpose we subjected yeast cells to isothermal osmotic dehydration, i.e. by solute addition, or to iso-osmotic heating. Finally, we studied the combined effects of temperature and water activity variation on cell viability.

Section snippets

Strains and growth conditions

Saccharomyces cerevisiae CBS 1171 was grown in 250-ml conical flasks containing 100 ml of a modified malt Wickerham medium (Gervais et al., 1992, Gervais and Martı́nez de Marañón, 1995). Cultures were held at 25°C on a rotary shaker and allowed to grow to early stationary phase.

Viability measurement

Cell viability was determined by vital staining (methylene blue stain) and microscopy as previously described (Martı́nez de Marañón et al., 1999). Briefly, the yeast suspension was mixed (v/v) with a methylene blue

Effect of isothermal osmotic dehydration

In a previous work (Marechal and Gervais, 1994), the rate of osmotic pressure increase was found to have a great effect on yeasts viability. S. cerevisiae can survive at very high levels of osmotic pressure (Π=100 MPa) when the extracellular osmotic pressure is increased slowly (1.6 MPa min⁻¹) up to 100 MPa. On the other hand, cell viability drastically decreases when yeast cells are suddenly placed (hyperosmotic shock, i.e. fast kinetics of osmotic pressure increase) in a hyperosmotic solution

References (5)

P. Gervais et al.
Effect of the kinetics of temperature variation on Saccharomyces cerevisiae viability and permeability
Biochim. Biophys. Acta
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P. Gervais et al.
Effects of the kinetics of osmotic pressure variation on yeast viability
Biotechnol. Bioeng.
(1992)

There are more references available in the full text version of this article.

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International Journal of Food Microbiology

Abstract

Introduction

Section snippets

Strains and growth conditions

Viability measurement

Effect of isothermal osmotic dehydration

References (5)

Effect of the kinetics of temperature variation on Saccharomyces cerevisiae viability and permeability

Biochim. Biophys. Acta

Effects of the kinetics of osmotic pressure variation on yeast viability

Biotechnol. Bioeng.

Cited by (41)

Microstructure evolution affecting the rehydration of dried mushrooms during instant controlled pressure drop combined hot air drying (DIC-HA)

Improving ambient temperature stability of probiotics with stress adaptation and fluidized bed drying

Dynamic model of temperature impact on cell viability and major product formation during fed-batch and continuous ethanolic fermentation in Saccharomyces cerevisiae

Effects of freezing treatments on the fermentative activity and gluten network integrity of sweet dough

Lateral reorganization of plasma membrane is involved in the yeast resistance to severe dehydration

The influence of attachment to beef surfaces on the survival of cells of Salmonella enterica serovar Typhimurium DT104, at different a<inf>w</inf> values and at low storage temperatures

Short communicationInfluence of thermal and osmotic stresses on the viability of the yeast Saccharomyces cerevisiae

Abstract

Introduction

Section snippets

Strains and growth conditions

Viability measurement

Effect of isothermal osmotic dehydration

Biochim. Biophys. Acta

Effects of the kinetics of osmotic pressure variation on yeast viability

Biotechnol. Bioeng.

Short communication
Influence of thermal and osmotic stresses on the viability of the yeast Saccharomyces cerevisiae