Search results for "SIAE"
showing 10 items of 787 documents
Yeast interaction on Chardonnay wine composition: Impact of strain and inoculation time.
2022
Abstract It is of great importance to understand the molecular characteristics and substantial chemical transformations due to yeast-yeast interaction. Non-targeted metabolomics was used to unravel must in fermentation composition, inoculated with non-Saccharomyces (NS) yeasts and Saccharomyces cerevisiae (S) for sequential fermentation. ultrahigh-resolution mass spectrometry was able to distinguish thousands of metabolites and provides deep insights into grape must composition allowing better understanding of the yeast-yeast interactome. The dominance of S, characterized by a metabolic richness not found with NS, is dependent on inoculation time and on the yeast species present. Co-inocula…
Relationship between Metabolic Fluxes and Sequence-Derived Properties of Enzymes
2014
Metabolic fluxes are key parameters of metabolic pathways being closely related to the kinetic properties of enzymes, thereby could be dependent on. This study examines possible relationships between the metabolic fluxes and the physical-chemical/structural features of enzymes from the yeast Saccharomyces cerevisiae glycolysis pathway. Metabolic fluxes were quantified by the COPASI tool using the kinetic models of Hynne and Teusink at varied concentrations of external glucose. The enzyme sequences were taken from the UniProtKB and the average amino acid (AA) properties were computed using the set of Georgiev’s uncorrelated scales that satisfy the VARIMAX criterion and specific AA indices th…
Purification and characterization of an exopolyphosphatase from Saccharomyces cerevisiae.
1994
An exopolyphosphatase (polyphosphate phosphohydrolase; EC 3.6.1.11) activity that cleaves inorganic polyphosphates to orthophosphate has been purified to apparent homogeneity (> 95% pure) from Saccharomyces cerevisiae. The exopolyphosphatase is a monomeric protein with a polypeptide molecular mass of 28 kDa. The enzyme, which can be stabilized in the presence of Triton X-100, has a pH optimum of 7.5 and requires, for maximal activity, Co2+ or Mg2+ ions. In the absence of these ions, the exopolyphosphatase binds to polyphosphate but does not degrade it, allowing affinity purification of the enzyme on a polyphosphate-modified zirconia support. o-Vanadate, Cu2+, and Ca2+ are effective inhibito…
Influence of fatty acids on the growth of wine microorganisms Saccharomyces cerevisiae and Oenococcus oeni
1998
The effects of fatty acids, extracted during prefermentation grape skin-contact on Saccharomyces cerevisiae and Oenococcus oeni, were studied. The influence of skin-contact on total fatty acid content was evaluated both in Chardonnay must and in synthetic medium. Prior to alcoholic fermentation, the skin-contact contributes to a large enrichment of long-chain fatty acids (C 16 to C 18:3 ). These results induced a positive effect on yeast growth and particularly on cell viability. In the skin-contact fermented media, levels of C 12 and especially C 10 are lower and macromolecules content higher than in controls. This production of extracellular mannoproteins and the reduction of medium-chain…
Determination of the stability of protein pools from the cell wall of fungi.
2002
Stability of the protein populations present in the cell wall of three ascomycetous fungi Candida albicans, Saccharomyces cerevisiae and Yarrowia lipolytica was investigated. Cell wall proteins were either labeled with biotin or radiolabeled with amino acids, and chased for a period of time representing several generations. Proteins linked by non-covalent or covalent bonds were separated and their turnover was analyzed. No significant turnover took place during the chase period, and in fact radioactive proteins were accumulated in the wall during the period possibly by transfer through the secretory pathway. This transfer did not involve de novo protein synthesis; it was inhibited by azide,…
Killer Toxins of Yeasts: Inhibitors of Fermentation and Their Adsorption.
2019
The killer toxin (KT 28), a glycoprotein of Saccharomyces cerevisiae strain 28, was almost completely adsorbed by bentonite, when applied at a concentration of 1 g per liter. No significant differences were found between several types of bentonite. Killer toxin KT 28 is similarly adsorbed by intact yeast cells or by a commercial preparation of yeast cell walls that has been recommended to prevent stuck fermentations. An investigation of the cell wall fractions revealed that the toxin KT 28 was mainly adsorbed by mannan, that removed the toxin completely. The alkali-soluble and the alkali-insoluble β-1,3- and β-1,6-D-glucans lowered the toxin concentration to one tenth of the original amount…
Impact of Starmerella bacillaris and Zygosaccharomyces bailii on ethanol reduction and Saccharomyces cerevisiae metabolism during mixed wine fermenta…
2021
AbstractThe bulk of grape juice fermentation is carried out by the yeast Saccharomyces cerevisiae, but non-Saccharomyces yeasts can modulate many sensorial aspects of the final products in ways not well understood. In this study, some of such non-conventional yeasts were screened as mixed starter cultures in a fermentation defined medium in both simultaneous and sequential inoculations. One strain of Starmerella bacillaris and another of Zygosaccharomyces bailii were chosen by their distinct phenotypic footprint and their ability to reduce ethanol levels at the end of fermentation, particularly during simultaneous vinification. S. bacillaris losses viability strongly at the end of mixed fer…
Characterization of hOGG1 Promoter Structure, Expression During Cell Cycle and Overexpression in Mammalian Cells
2001
Oxygen radicals are produced in all cells either by the normal cellular metabolism or by the exposure to external mutagens. The reactive oxygen species (ROS) generated can induce DNA damage. Among the principal lesions found in DNA due to ROS is an oxidized form of guanine, 8-oxo-7,8-dihydroguanine (8-oxoG). The biological relevance of this lesion has been unveiled by the study of Escherichia colt and Saccharomyces cerevisiae genes involved in the neutralization of the mutagenic effects of 8-oxoG (Cabrera et al., 1988; Nghiem et al., 1988; Radicella et al., 1988; van der Kemp et al., 1996). These genes fpg and mutY for E. colt and OGG1 for yeast, code for DNA glycosylases. Inactivation of a…
Interaction Between Osmotic and Hydrostatic Pressure in Yeast Inactivation
1999
The protective effect of an osmotic perturbation on high-pressure inactivation has been investigated using a yeast strain:Saccharomyces cerevisiae. Osmotic shocks have been carried out with binary medium (glycerol/sorbitol and water) with or without glucose. Variations of osmotic level, osmotic shift kinetics and time between osmotic and hydrostatic treatment (350 MPa/10 min) have allowed the characterization of cell baroprotection. Two different cumulative baroprotection effects have been distinguished: one conferred by the solute on biological structures and the other related to the osmotic stress, cell volume variations and stress metabolism response (HSP, trehalose). These experiments h…
The hedgehog receptor patched is involved in cholesterol transport.
2011
International audience; BACKGROUND: Sonic hedgehog (Shh) signaling plays a crucial role in growth and patterning during embryonic development, and also in stem cell maintenance and tissue regeneration in adults. Aberrant Shh pathway activation is involved in the development of many tumors, and one of the most affected Shh signaling steps found in these tumors is the regulation of the signaling receptor Smoothened by the Shh receptor Patched. In the present work, we investigated Patched activity and the mechanism by which Patched inhibits Smoothened. METHODOLOGY/PRINCIPAL FINDINGS: Using the well-known Shh-responding cell line of mouse fibroblasts NIH 3T3, we first observed that enhancement …