Yeast cell responses to water potential variations

Marechal, Pierre-André; Marañón, Iñigo Martı́nez de; Molin, Paul; Gervais, Patrick

doi:10.1016/0168-1605(95)00063-1

Cited by 21 publications

(32 citation statements)

References 14 publications

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“…3; Fig. S1 in “Supplementary material”) and took one data set from the literature (Marechal et al 1995) (data set 4 in Fig. 3; Fig.…”

Section: Methodsmentioning

confidence: 99%

“…It is recognized that turgor plays a vital role in growth (Cosgrove 1981; Zimmermann 1978; Marechal and Gervais 1994), cell structure (Cosgrove 1993; Morris et al 1986; Zhongcan and Helfrich 1987; Munns et al 1983), and membrane transport processes (Zimmermann 1978; Lande et al 1995; Kamiya et al 1963; Soveral et al 2008) and that it may be sensed by the cells as an indicator of external osmotic changes (Tamas et al 2000; Coster et al 1976; Schmalstig and Cosgrove 1988; Reiser et al 2003). Therefore, quantifying cell wall and membrane properties, and thus the resulting turgor pressure, has been the aim of numerous studies (Cosgrove 1981; Morris et al 1986; Munns et al 1983; Kamiya et al 1963; Coster et al 1976; Smith et al 1998, 2000a, b, c; Marechal et al 1995; Gervais et al 1996a; Cosgrove 2000). Parameterized models of turgor pressure, based on cell wall and membrane properties are especially important for quantitative mathematical models describing the interdependence between water transport and signaling processes (Schaber and Klipp 2008; Klipp et al 2005; Gennemark et al 2006; Kargol and Kargol 2003a, 2003).…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, the few reports in which turgor and/or cell wall elasticity were quantitatively determined used non-physiological experimental conditions. For example, one study used pre-stressed cells (Marechal et al 1995) and in two others, the cells were suspended in distilled water before volume measurements (Smith et al 2000b, c). …”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Biophysical properties of Saccharomyces cerevisiae and their relationship with HOG pathway activation

et al. 2010

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Parameterized models of biophysical and mechanical cell properties are important for predictive mathematical modeling of cellular processes. The concepts of turgor, cell wall elasticity, osmotically active volume, and intracellular osmolarity have been investigated for decades, but a consistent rigorous parameterization of these concepts is lacking. Here, we subjected several data sets of minimum volume measurements in yeast obtained after hyper-osmotic shock to a thermodynamic modeling framework. We estimated parameters for several relevant biophysical cell properties and tested alternative hypotheses about these concepts using a model discrimination approach. In accordance with previous reports, we estimated an average initial turgor of 0.6 ± 0.2 MPa and found that turgor becomes negligible at a relative volume of 93.3 ± 6.3% corresponding to an osmotic shock of 0.4 ± 0.2 Osm/l. At high stress levels (4 Osm/l), plasmolysis may occur. We found that the volumetric elastic modulus, a measure of cell wall elasticity, is 14.3 ± 10.4 MPa. Our model discrimination analysis suggests that other thermodynamic quantities affecting the intracellular water potential, for example the matrix potential, can be neglected under physiological conditions. The parameterized turgor models showed that activation of the osmosensing high osmolarity glycerol (HOG) signaling pathway correlates with turgor loss in a 1:1 relationship. This finding suggests that mechanical properties of the membrane trigger HOG pathway activation, which can be represented and quantitatively modeled by turgor.Electronic supplementary materialThe online version of this article (doi:10.1007/s00249-010-0612-0) contains supplementary material, which is available to authorized users.

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“…3; Fig. S1 in “Supplementary material”) and took one data set from the literature (Marechal et al 1995) (data set 4 in Fig. 3; Fig.…”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Biophysical properties of Saccharomyces cerevisiae and their relationship with HOG pathway activation

et al. 2010

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“…Beyond industrial concern, understanding the phenomenon of xerotolerance is of relevance for the biodiversity of yeasts in natural habitats such as plant nectars and saps or salt ponds, where ecological factors are exerted in high solute concentrations. Data from Marechal et al (1995) …”

Section: Watermentioning

confidence: 99%

“…Water should be fluid and free (not chemically bound) in order to be absorbed. The availability of water is usually expressed in terms of water activity (a w ); the more exact physicochemical term water potential (ψ) is used less frequently in microbial ecology (Marechal et al 1995).…”

Section: Watermentioning

confidence: 99%

Environmental Factors Influencing Yeasts

Deák

The Yeast Handbook

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Yeasts are ubiquitous microorganisms that form part of the microbiota of most if not all natural ecosystems. A wide variety of yeast species occur in soil, fresh water and marine water, they are normal inhabitants on plants, are commonly associated with animals, and are also found frequently in man-made habitats such as foods. The conditions prevailing in these natural and artificial habitats determine the metabolic activity, growth and survival of yeasts. A variety of abiotic and biotic factors influence the life of yeasts, and exert stress conditions which the cells must withstand and adapt to or otherwise they die. Death of individual cells may not bring about the extinction of a whole population as there is a large variation in resistance to stress factors among cells. Also, these factors change with time and show spatial heterogeneity; their effect is manifested differently in microenvironments. So, when looking at the environmental relations of yeasts, we should deal with a very complex interrelation of factors that are only partially understood. Nevertheless, basic knowledge of these is important for understanding the ecology and biodiversity of yeasts as well as to control the environmental factors in order to enhance the exploitation of yeasts or to inhibit or stop their harmful and deleterious activity.In this chapter our current knowledge of the environmental relations of yeasts is summarized. First, the most relevant physical, chemical and biotic factors and their interactions are described in a changing environment. Further on, responses of yeast cells to stress conditions are discussed at single cell and population level. In-depth treatment of the genetic background of variation, and the mechanism of adaptation to stress factors would be beyond the limits of this chapter. Further chapters in this book are devoted to their discussion. Reference is made to relevant literature and to the large amount of data covered and summarized in previous works and reviews

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Inline characterization of cell concentration and cell volume in agitated bioreactors using in situ microscopy: Application to volume variation induced by osmotic stress

Camisard

Brienne

Baussart

et al. 2002

Biotech & Bioengineering

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A new in situ microscope (ISM) was developed and tested to perform in-line monitoring of average cell volume and cell concentration in agitated cultures subjected to osmotic stress. The ISM is directly immersed into the agitated broth in a bioreactor and generates still images of cells by using pulsed luminescent diode illumination and a virtual probe volume defined by depth of focus. This technique allows the acquisition of microscopic still images without mechanical sampling techniques. The front end of the sensor fits into a standard 25-mm port and it can be steam sterilized together with the bioreactor. The automatic image evaluation generates signals of the cell concentration and the average cell volume with a time resolution of a few minutes per data point (if a 200 MHz PC is used). Without the need for evaluation, the images can be acquired and stored at a rate of one image per 0.6 s. Hansenula anomala was cultivated as batch fermentation and monitored inline with the ISM. The ISM signal of the cell concentration agreed well with referential growth curves that were obtained from counting with a hemocytometer. The ISM signal of the average cell volume shows a gradual volume reduction as a result of the aging of the culture, and it monitors an abrupt and strong cell contraction if osmotic shocks are generated in the bioreactor. Systematic in vitro studies of osmotic shocks were performed by applying the ISM to agitated culture samples of H. anomala. The volume signal of H. anomala during osmotic shocks showed a very fast cell contraction within less than a second. Within half an hour after the shocks, no signal drifts were observed, which would indicate volume restoration. These findings suggest that the ISM volume signal can be used as an inline indicator of osmotic stress in cell cultures.

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Yeast cell responses to water potential variations

Cited by 21 publications

References 14 publications

Biophysical properties of Saccharomyces cerevisiae and their relationship with HOG pathway activation

Biophysical properties of Saccharomyces cerevisiae and their relationship with HOG pathway activation

Environmental Factors Influencing Yeasts

Inline characterization of cell concentration and cell volume in agitated bioreactors using in situ microscopy: Application to volume variation induced by osmotic stress

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