Search results for "Saccharomyces cerevisiae"
showing 10 items of 738 documents
Enhanced enzymatic activity of glycerol-3-phosphate dehydrogenase from the cryophilic Saccharomyces kudriavzevii
2014
During the evolution of the different species classified within the Saccharomyces genus, each one has adapted to live in different environments. One of the most important parameters that have influenced the evolution of Saccharomyces species is the temperature. Here we have focused on the study of the ability of certain species as Saccharomyces kudriavzevii to grow at low temperatures, in contrast to Saccharomyces cerevisiae. We observed that S. kudriavzevii strains isolated from several regions are able to synthesize higher amounts of glycerol, a molecule that has been shown to accumulate in response to freeze and cold stress. To explain this observation at the molecular level we studied t…
The yeast osmosensitive mutant fps1Δ transformed by the cauliflower BobTIP1;1 aquaporin withstand a hypo-osmotic shock
2005
AbstractOsmoregulation plays an important role in cellular responses to osmotic stress in plants and in yeast. Aquaporins contribute to osmotic adjustment by facilitating transport of water or solutes across membranes. The tonoplastic water channel BobTIP1;1 (original name BobTIP26-1) genes are upregulated during dessication stress in cauliflower meristematic tissue. To investigate the physiological importance of BobTIP1;1, we expressed it in a Saccharomyces cerevisiae osmosensitive mutant fps1Δ. We showed that the defect in the yeast glycerol plasma membrane transporter is complemented by a plant cDNA encoding the aquaporin BobTIP1;1 which is localized in the vacuolar membrane of the compl…
Molecular and enological characterization of a natural Saccharomyces uvarum and Saccharomyces cerevisiae hybrid
2015
Available online 17 March 2015
Msb2 is a Ste11 membrane concentrator required for full activation of the HOG pathway.
2015
The high osmolarity glycerol (HOG) pathway, composed of membrane-associated osmosensors, adaptor proteins and core signaling kinases, is essential for the survival of yeast cells under hyper-osmotic stress. Here, we studied how the MAPKKK Ste11 might change its protein interaction profile during acute stress exposure, with an emphasis on the sensory system of the so-called Sho1/Msb2 signaling branch. To characterize the transience of protein-protein interactions we utilized a recently described enzymatic in vivo protein proximity assay (M-track). Accordingly, interaction signals between Ste11 and many of its signaling partners can already be detected even under basal conditions. In most cas…
The role of glycerol transporters in yeast cells in various physiological and stress conditions.
2015
Small and uncharged glycerol is an important molecule for yeast metabolism and osmoadaptation. Using a series of S. cerevisiae BY4741-derived mutants lacking genes encoding a glycerol exporter (Fps1p) and/or importer (Stl1p) and/or the last kinase of the HOG pathway (Hog1p), we studied their phenotypes and various physiological characteristics with the aim of finding new roles for glycerol transporters. Though the triple mutant hog1Δ stl1Δ fps1Δ was viable, it was highly sensitive to various stresses. Our results showed that the function of both Stl1p and Fps1p transporters contributes to the cell ability to survive during the transfer into the state of anhydrobiosis, and that the deletion …
The yeast Starmerella bacillaris (synonym Candida zemplinina) shows high genetic diversity in winemaking environments.
2015
International audience; The yeast Candida zemplinina (Starmerella bacillaris) is frequently isolated from grape and wine environments. Its enological use in mixed fermentation with Saccharomyces cerevisiae has been extensively investigated these last few years, and several interesting features including low ethanol production, fructophily, glycerol and other metabolites production, have been described. In addition, molecular tools allowing the characterization of yeast populations have been developed, both at the inter- and intraspecific levels. However, most of these fingerprinting methods are not compatible with population genetics or ecological studies. In this work, we developed 10 micr…
Modulation of the glycerol and ethanol syntheses in the yeast Saccharomyces kudriavzevii differs from that exhibited by Saccharomyces cerevisiae and …
2010
In the last years there is an increasing demand to produce wines with higher glycerol levels and lower ethanol contents. The production of these compounds by yeasts is influenced by many environmental variables, and could be controlled by the choice of optimized cultivation conditions. The present work studies, in a wine model system, the effects of temperature, pH and sugar concentration on the glycerol and ethanol syntheses by yeasts Saccharomyces cerevisiae T73, the type strain of Saccharomyces kudriavzevii IFO 1802(T), and an interspecific hybrid between both species (W27), which was accomplished by the application of response surface methodology based in a central composite circumscrib…
Differential expression of the invertase-encoding SUC genes in Saccharomyces cerevisiae
1992
Invertase (INV) is encoded in Saccharomyces cerevisiae by a family of genes, comprising SUC1-SUC5 and SUC7. Production of INV is highly variable, dependent on the strain and SUC gene present in the cell. The differences in INV production derive from the structure of the genes or are dependent on the genetic background of the strain. Centromeric plasmids (based on YCp50) carrying one of the SUC genes (except SUC7) were introduced into a strain (SEY2101) lacking SUC genes. The INV produced by the transformants was dependent on the individual SUC genes, and correlated with INV mRNA levels. Plasmids in which SUC2 had been placed under control of promoters from the other SUC genes, were used to …
Quantitation of Free and Glycosidically Bound Volatiles in and Effect of Glycosidase Addition on Three Tomato Varieties (Solanum lycopersicumL.)
2007
The volatile fractions of three tomato cultivars (p73, Jorge, and Durinta) were studied in both free and glycosidically bound forms. The possibility of increasing the concentration of free volatile compounds by adding selected glycosidases was also tested. The free volatile fraction (FVF) of tomato juice was directly determined by headspace solid-phase microextraction (SPME). To analyze the glycosidically bound fraction (GBF), tomato juice samples were extracted with C18 cartridges and the resulting glycoside extracts were enzymatically hydrolyzed. The released aglycons were determined by headspace SPME. Of these compounds, six were not previously reported to belong to the tomato GBF. The c…
Phenotype traits associated with different alleles at the RPS5 locus in Saccharomyces cerevisiae
1992
The RPS5 gene has been characterised through its ability to reduce invertase production by the SUC5 gene. In this paper we show that RPS5 acts by maintaining low levels of SUC5 mRNA. We also show that RPS5 acts on the SUC1 and SUC4 genes but not on SUC2 and SUC3, which are members of the SUC family. RPS5 also shows a pleiotropic effect on the amount of mitochondrial cytochromes.