Search results for "VISIA"
showing 10 items of 764 documents
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 …
Unveiling adaptive mechanisms though experimental evolution: the role of duplicated genes and phenotypic plasticity in yeast, and the genetic variabi…
2021
Los seres vivos se enfrentan a condiciones ambientales cambiantes y habitualmente estresantes, agravadas por el cambio climático, que ponen a prueba su capacidad de supervivencia. El cambio en la composición genética de las poblaciones reside en las mutaciones, que son la fuente para la evolución y la adaptación a los cambios. La diversidad genética intrapoblacional está regulada por dos grandes fuerzas evolutivas que cambian la composición genética permitiendo así el acceso a nuevos fenotipos: la deriva genética y la selección natural. Por un lado, la deriva genética fija mutaciones en la población de manera aleatoria e independiente del efecto que suponga dicha mutación para la población.…
Differential Translational Efficiency of the mRNAs Isolated from Derepressed and Glucose Repressed Saccharomyces cerevisiae
1987
Summary: Carbon catabolite derepression induced changes in the pool of yeast mRNAs translatable in a protein-synthesizing reticulocyte system. Competition experiments with globin mRNA showed that the mRNA population obtained from derepressed cells possessed a higher translational efficiency than mRNA from repressed cells. The mRNAs that could account for the high translational efficiency of the derepressed mRNA were not detected in cells growing in glucose-rich medium. Analysis of protein synthesis in the presence of 7-methylguanosine 5′-phosphate indicated that the initiation factors recognizing the 5′-terminal structure of capped messengers interacted with lower affinity with the represse…
Identification of a Functional Homolog of the Yeast Copper Homeostasis Gene ATX1 from Arabidopsis1
1998
Abstract A cDNA clone encoding a homolog of the yeast (Saccharomyces cerevisiae) gene Anti-oxidant 1(ATX1) has been identified from Arabidopsis. This gene, referred to as CopperCHaperone(CCH), encodes a protein that is 36% identical to the amino acid sequence of ATX1 and has a 48-amino acid extension at the C-terminal end, which is absent from ATX1 homologs identified in animals. ATX1-deficient yeast (atx1) displayed a loss of high-affinity iron uptake. Expression of CCH in the atx1 strain restored high-affinity iron uptake, demonstrating thatCCH is a functional homolog of ATX1. When overexpressed in yeast lacking the superoxide dismutase geneSOD1, both ATX1 and CCHprotected the cell from t…
Rauga biomasas ietekme uz aktīvo dūņu mikroorganismu fizioloģisko stāvokli benzalkonija hlorīda klātbūtnē
2019
Maģistra darba mērķis bija izvērtēt rauga Saccharomyces cerevisiae 14 ietekmi uz aktīvo dūņu baktēriju kopienas sastāvu un to aktivitāti benzalkonija hlorīda klātbūtnē. Eksperimentos ar aktīvajām dūņām un notekūdeņiem no ķīmiskās rūpnīcas, kā arī ar sintētiskajiem notekūdeņiem, tika pierādīta rauga S.cerevisiae 14 stimulējošā iedarbība uz aktīvo dūņu mikroorganismu fizioloģiskajiem procesiem, t.sk elpošanas intensitāti. Rauga ietekme uz aktīvo dūņu mikroorganismiem BAC klātbūtnē tika vērtēta pēc hidrolītisko enzīmu aktivitātes, kultivējamo mikroorganismu skaita, baktēriju kopienas sastāva u.c. Darba izstrādē tika pielietotas klasiskās mikrobioloģijas un bioķīmiskās metodes, Ion-Torrent PGM …
Análisis de los mecanismos de respuesta a bajas temperaturas y a estrés del retículo endoplásmico
2013
A lo largo de los años, la levadura S. cerevisiae se ha convertido en organismo modelo tanto en la industria, como en el campo de la investigación básica, debido a sus características metabólicas y su fácil manipulación. Es conocido que, cuando la célula se enfrenta a una situación de estrés, debe modificar su fisiología para mantener la homeostasis celular. Esta adaptación incluye la regulación del repertorio de proteínas, eliminando aquellas que ya no son necesarias o sintetizando otras nuevas. En este proceso, un orgánulo crucial es el retículo endoplásmico, que establece un punto de control en la calidad de las proteínas, ya que es el responsable de su glicosilación y correcto plegamien…