Release of nitrogen compounds to the extracellular medium by three strains of Saccharomyces cerevisiae during induced autolysis in a model wine system

2001 ◽  
Vol 68 (1-2) ◽  
pp. 155-160 ◽  
Author(s):  
A.J Martı́nez-Rodriguez ◽  
A.V Carrascosa ◽  
M.C Polo
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Nitrogen Compounds ◽  
Extracellular Medium ◽  
Induced Autolysis

scholarly journals Polyhydroxyfullerene Binds Cadmium Ions and Alleviates Metal-Induced Oxidative Stress in Saccharomyces cerevisiae

2014 ◽  
Vol 80 (18) ◽  
pp. 5874-5881 ◽  
Author(s):  
Arunava Pradhan ◽  
José Paulo Pinheiro ◽  
Sahadevan Seena ◽  
Cláudia Pascoal ◽  
Fernanda Cássio
Keyword(s):  
Oxidative Stress ◽  
Saccharomyces Cerevisiae ◽  
Antioxidant Properties ◽  
Water Soluble ◽  
Interactive Effects ◽  
Membrane Disruption ◽  
Dependent Manner ◽  
Extracellular Medium ◽  
Cadmium Ions ◽  
Ph Dependent

ABSTRACTThe water-soluble polyhydroxyfullerene (PHF) is a functionalized carbon nanomaterial with several industrial and commercial applications. There have been controversial reports on the toxicity and/or antioxidant properties of fullerenes and their derivatives. Conversely, metals have been recognized as toxic mainly due to their ability to induce oxidative stress in living organisms. We investigated the interactive effects of PHF and cadmium ions (Cd) on the model yeastSaccharomyces cerevisiaeby exposing cells to Cd (≤5 mg liter−1) in the absence or presence of PHF (≤500 mg liter−1) at different pHs (5.8 to 6.8). In the absence of Cd, PHF stimulated yeast growth up to 10.4%. Cd inhibited growth up to 79.7%, induced intracellular accumulation of reactive oxygen species (ROS), and promoted plasma membrane disruption in a dose- and pH-dependent manner. The negative effects of Cd on growth were attenuated by the presence of PHF, and maximum growth recovery (53.8%) was obtained at the highest PHF concentration and pH. The coexposure to Cd and PHF decreased ROS accumulation up to 36.7% and membrane disruption up to 30.7% in a dose- and pH-dependent manner. Two mechanisms helped to explain the role of PHF in alleviating Cd toxicity to yeasts: PHF decreased Cd-induced oxidative stress and bound significant amounts of Cd in the extracellular medium, reducing its bioavailability to the cells.

Yeast adapted to wine: Nitrogen compounds released during induced autolysis in a model wine

2002 ◽  
Vol 29 (3) ◽  
pp. 134-139
Author(s):  
L Perrot ◽  
M Charpentier ◽  
C Charpentier ◽  
M Feuillat ◽  
D Chassagne
Keyword(s):  
Nitrogen Compounds ◽  
Induced Autolysis

Yeast adapted to wine: Nitrogen compounds released during induced autolysis in a model wine

2002 ◽  
Vol 29 (3) ◽  
pp. 134-139 ◽  
Author(s):  
L Perrot ◽  
M Charpentier ◽  
C Charpentier ◽  
M Feuillat ◽  
D Chassagne
Keyword(s):  
Nitrogen Compounds ◽  
Induced Autolysis

scholarly journals Weak acid and alkali stress regulate phosphatidylinositol bisphosphate synthesis in Saccharomyces cerevisiae

2006 ◽  
Vol 395 (1) ◽  
pp. 73-80 ◽  
Author(s):  
Mehdi Mollapour ◽  
John P. Phelan ◽  
Stefan H. Millson ◽  
Peter W. Piper ◽  
Frank T. Cooke
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Stress Responses ◽  
Acid Stress ◽  
Weak Acid ◽  
Weak Acids ◽  
Extracellular Medium ◽  
Food Preservatives ◽  
Active Efflux ◽  
Signalling Molecules ◽  
Spoilage Yeasts

Weak organic acids are used as food preservatives to inhibit the growth of spoilage yeasts, including Saccharomyces cerevisiae. Long-term adaptation to weak acids requires the increased expression of the ATP-binding cassette transporter Pdr12p, which catalyses the active efflux of the weak acids from the cytosol; however, very little is known about the signalling events immediately following application of weak acid stress. We have investigated the effects of weak acids on two stress-responsive signalling molecules, PtdIns(3,5)P2 and PtdIns(4,5)P2, which in S. cerevisiae are synthesized by Fab1p and Mss4p respectively. At low extracellular pH, benzoic acid, sorbic acid and acetic acid all cause a transient reduction in PtdIns(3,5)P2 accumulation and a more persistent rise in PtdIns(4,5)P2 levels. The increase in PtdIns(4,5)P2 levels is accompanied by a reorganization of the actin cytoskeleton. However, changes in PtdInsP2 levels are independent of weak acid-induced Pdr12p expression. In contrast, changing the extracellular medium to alkaline pH provokes a prolonged and substantial rise in PtdIns(3,5)P2 levels. As PtdIns(3,5)P2 synthesis is required for correct vacuole acidification, it is possible that levels of this molecule are modulated to maintain intracellular pH homoeostasis in response to weak acid and alkali stresses. In conclusion, we have expanded the repertoire of stress responses that affect PtdInsP2 levels to include weak acid and alkali stresses.

scholarly journals Complex modulation of cation channels in the tonoplast and plasma membrane of Saccharomyces cerevisiae: single-channel studies.

1992 ◽  
Vol 172 (1) ◽  
pp. 271-287
Author(s):  
A Bertl ◽  
C L Slayman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Plasma Membrane ◽  
Single Channel ◽  
K Channel ◽  
Substrate Uptake ◽  
Alkaline Ph ◽  
Open Probability ◽  
Extracellular Medium ◽  
Yeast Saccharomyces Cerevisiae ◽  
Charge Balancing

Detailed patch-clamp studies have been made of ion channels in the plasma membrane and tonoplast of the yeast Saccharomyces cerevisiae. The predominant tonoplast channel is a high-conductance cation-selective inward rectifier (passing ions easily into the cytoplasm from the vacuole), with its open probability (Po) peaking at about -80 mV (cytoplasm negative) and falling to near zero at +80 mV. It has a maximal slope conductance of approximately 150 pS in 100 mmol l-1 KCl, and conducts Na+, K+ and Ca2+. Elevated cytoplasmic Ca2+ concentration, alkaline pH and reducing agents can activate the channel, its likely physiological function being to adjust cytoplasmic Ca2+ concentration from the vacuolar reservoir. The predominant plasma-membrane channel is a strongly outward rectifying K+ channel (passing K+ easily out of the cytoplasm to the extracellular medium), which is activated by positive-going membrane voltages as well as by elevated cytoplasmic Ca2+ concentration and alkaline pH. Interaction between membrane voltage and [Ca2+]cyt is complex and defines three parallel closed states for the channel: a Ca(2+)-independent brief closure (I), a calcium-inhibited long closure (G) and, at large positive voltages, a calcium-induced brief blockade (B). This channel is likely to function in steady-state turgor regulation and in charge balancing during proton-coupled substrate uptake.

scholarly journals New Nitrogen Compounds Coupled to Phenolic Units with Antioxidant and Antifungal Activities: Synthesis and Structure–Activity Relationship

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2530 ◽  
Author(s):  
Ana Bettencourt ◽  
Marián Castro ◽  
João Silva ◽  
Francisco Fernandes ◽  
Olga Coutinho ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Inhibitory Concentration ◽  
Yeast Species ◽  
Nitrogen Compounds ◽  
Dpph Radical ◽  
Therapeutic Drugs ◽  
Structure Activity ◽  
Deoxyribose Degradation ◽  
New Compounds ◽  
Selection Of

A selection of 1-amino-2-arylidenamine-1,2-(dicyano)ethenes 3 was synthesized and cyclized to 2-aryl-4,5-dicyano-1H-imidazoles 4 upon reflux in ethyl acetate/acetonitrile, in the presence of manganese dioxide. These compounds were tested for their antioxidant capacity by cyclic voltammetry, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and deoxyribose degradation assays. The minimum inhibitory concentration of all compounds was evaluated against two yeast species, Saccharomyces cerevisiae and Candida albicans. Their toxicity was tested in mammal fibroblasts. Among the synthesised compounds, two presented dual antioxidant/antifungal activity without toxic effects in fibroblasts. The new compounds synthesized in this work are potential biochemical tools and/or therapeutic drugs.

scholarly journals Signal processing, glycosylation, and secretion of mutant hemagglutinins of a human influenza virus by Saccharomyces cerevisiae.

1987 ◽  
Vol 7 (4) ◽  
pp. 1476-1485 ◽  
Author(s):  
M Abdul Jabbar ◽  
D P Nayak
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Influenza Virus ◽  
Signal Peptide ◽  
Signal Sequence ◽  
Human Influenza ◽  
Extracellular Medium ◽  
Yeast Saccharomyces Cerevisiae ◽  
Human Influenza Virus ◽  
Cdna Sequences ◽  
Transport Patterns

We investigated the nature of signal recognition, transport, and secretion of mutant hemagglutinins (HAs) of a human influenza virus by the yeast Saccharomyces cerevisiae. The cDNA sequences encoding variant forms of influenza HA were expressed in S. cerevisiae. The HA polypeptides (HA500 and HA325) that were synthesized with their N-terminal signal peptides were correctly targeted to the membrane compartment where they were glycosylated. In contrast, the HA polypeptides (HA484 and HA308) lacking the signal peptide were expressed in the cytoplasm and did not undergo any glycosidic modification, demonstrating the importance of the heterologous signal sequence in the early steps of translocation in S. cerevisiae. The analysis of the N-terminal amino acid sequence of HA500 and HA325 polypeptides demonstrated the correct cleavage of the signal peptide, indicating the structural compatibility of a heterologous signal peptide for efficient recognition and processing by the yeast translocation machinery. The membrane-sequestered and glycosylated HA polypeptides were relatively stable in S. cerevisiae compared with the signal-minus, nonglycosylated HA molecules. Although both the anchor-minus HA (HA500) and HA1 (HA325) polypeptides were targeted efficiently to the membrane, their glycosylation and transport patterns were shown to be different. During pulse-chase, the HA500 remained cell-associated with no detectable secretion into the extracellular medium, whereas the HA325 secreted into the medium. Furthermore, only the cell-associated and secreted forms of HA325 and not HA500 appeared to have undergone hyperglycosylation with the extensive addition of high-molecular-weight outer-chain mannans. Possible reasons for the observed phenotypic behavior of these two mutant HAs are discussed.

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