scholarly journals Stress Resistance and Adhesive Properties of Commercial Flor and Wine Strains, and Environmental Isolates of Saccharomyces cerevisiae

Fermentation ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 188
Author(s):  
Michail A. Eldarov ◽  
Daria A. Avdanina ◽  
Elena Ivanova ◽  
Maksim Y. Shalamitskiy ◽  
Tatiana N. Tanashchuk ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Stress Resistance ◽  
Rapid Screening ◽  
Clear Correlation ◽  
Yeast Culture ◽  
Environmental Isolates ◽  
Adhesive Properties ◽  
Experimental Conditions ◽  
Culture Collections ◽  
Flor Yeast

Flor strains of Saccharomyces cerevisiae represent a special group of yeasts used for producing biologically aged wines. We analyzed the collection of commercial wine and flor yeast strains, as well as environmental strains isolated from the surface of grapes growing in vineyards, for resistance to abiotic stresses, adhesive properties, and the ability to form a floating flor. The degree of resistance of commercial strains to ethanol, acetaldehyde, and hydrogen peroxide was generally not higher than that of environmental isolates, some of which had high resistance to the tested stress agents. The relatively low degree of stress resistance of flor strains can be explained both by the peculiarities of their adaptive mechanisms and by differences in the nature of their exposure to various types of stress in the course of biological wine aging and under the experimental conditions we used. The hydrophobicity and adhesive properties of cells were determined by the efficiency of adsorption to polystyrene and the distribution of cells between the aqueous and organic phases. Flor strains were distinguished by a higher degree of hydrophobicity of the cell surface and an increased ability to adhere to polystyrene. A clear correlation between biofilm formation and adhesive properties was also observed for environmental yeast isolates. The overall results of this study indicate that relatively simple tests for cell hydrophobicity can be used for the rapid screening of new candidate flor strains in yeast culture collections and among environmental isolates.

Effects of dietary supplemental baker's yeast (Saccharomyces cerevisiae) and niacin on milk yield and milk composition of dairy cows

1998 ◽  
Vol 1998 ◽  
pp. 217-217
Author(s):  
A.R. Tasdemir ◽  
M. Gorgulu
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dairy Cows ◽  
Milk Yield ◽  
Synergistic Effects ◽  
Milk Composition ◽  
Baker’S Yeast ◽  
Feed Additives ◽  
Yeast Culture ◽  
Baker's Yeast ◽  
Experimental Conditions

In the last twenty years, some probiotics, such as Aspergillus oryzae or A. niger (Pioneer, 1989), yeast culture (Saccharomyces cerevisiae) (Wallace, 1994) and some microbial growth promoters (e.g. thiamine, niacin) (Shield, 1981), were used as feed additives in order to improve rumen conditions and cellulose digestion in the rumen and milk yield of dairy cows. The present study was planned to determine whether dietary supplemental baker's yeast and niacin would have individual and/or synergistic effects on milk yield and milk composition of dairy cows under our experimental conditions.

scholarly journals Hybridization of Saccharomyces cerevisiae Sourdough Strains with Cryotolerant Saccharomyces bayanus NBRC1948 as a Strategy to Increase Diversity of Strains Available for Lager Beer Fermentation

2020 ◽  
Author(s):  
Martina Catallo ◽  
Fabrizio Iattici ◽  
Cinzia Randazzo ◽  
Cinzia Caggia ◽  
Kristoffer Krogerus ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
De Novo ◽  
Yeast Culture ◽  
Culture Collections ◽  
Lager Yeast ◽  
Ethyl Hexanoate ◽  
Brewing Yeast ◽  
Saccharomyces Bayanus ◽  
Lager Beer ◽  
Saccharomyces Eubayanus

The search for novel brewing strains from non-brewing environments represents an emerging trend to increase genetic and phenotypic diversities in brewing yeast culture collections. Another valuable tool is hybridization, where beneficial traits of individual strains are combined in a single organism. This has been used successfully to create de novo hybrids from parental brewing strains by mimicking natural Saccharomyces cerevisiae ale x Saccharomyces eubayanus lager yeast hybrids. Here, we integrated both these approaches to create synthetic hybrids for lager fermentation using parental strains from niches other than beer. Using a phenotype-centered strategy, S. cerevisiae sourdough strains and the S. eubayanus x Saccharomyces uvarum strain NBRC1948 (also referred to as Saccharomyces bayanus) were chosen for their brewing aptitudes. We demonstrated that, in contrast to S. cerevisiae x S. uvarum crosses, hybridization yield was positively affected by time of exposure to starvation, but not by staggered mating. In laboratory-scale fermentation trials at 20°C, one triple S. cerevisiae x S. eubayanus x S. uvarum hybrid showed a heterotic phenotype compared with the parents. In 2L wort fermentation trials at 12°C, this hybrid inherited the ability to consume efficiently maltotriose from NBRC1948 and, like the sourdough S. cerevisiae parent, produced appreciable levels of the positive aroma compounds 3-methylbutyl acetate (banana/pear), ethyl acetate (general fruit aroma) and ethyl hexanoate (green apple, aniseed, and cherry aroma). Based on these evidences, the phenotype-centered approach appears promising for design of de novo lager beer hybrids and may help to diversify aroma profiles in lager beers.

Effects of dietary supplemental baker's yeast (Saccharomyces cerevisiae) and niacin on milk yield and milk composition of dairy cows

1998 ◽  
Vol 1998 ◽  
pp. 217-217
Author(s):  
A.R. Tasdemir ◽  
M. Gorgulu
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Dairy Cows ◽  
Milk Yield ◽  
Synergistic Effects ◽  
Milk Composition ◽  
Baker’S Yeast ◽  
Feed Additives ◽  
Yeast Culture ◽  
Baker's Yeast ◽  
Experimental Conditions

In the last twenty years, some probiotics, such as Aspergillus oryzae or A. niger (Pioneer, 1989), yeast culture (Saccharomyces cerevisiae) (Wallace, 1994) and some microbial growth promoters (e.g. thiamine, niacin) (Shield, 1981), were used as feed additives in order to improve rumen conditions and cellulose digestion in the rumen and milk yield of dairy cows. The present study was planned to determine whether dietary supplemental baker's yeast and niacin would have individual and/or synergistic effects on milk yield and milk composition of dairy cows under our experimental conditions.

Microfluidic Quantification of Yeast Surface Adhesion

2018 ◽  
Author(s):  
Kristina Reinmets ◽  
Amin Dehkharghani ◽  
Jeffrey S. Guasto ◽  
Stephen Fuchs
Keyword(s):  
Genetic Background ◽  
Food Production ◽  
Rapid Screening ◽  
Surface Adhesion ◽  
Adhesive Properties ◽  
Fungal Adhesion ◽  
Yeast Surface ◽  
Population Scale

<div>Fungal adhesion is fundamental to processes ranging from</div><div>infection to food production yet, robust, population-scale</div><div>quantification methods for yeast surface adhesion are lacking. We developed a microfluidic assay to distinguish the effects of genetic background and solution conditions on adhesion. This approach will enable the rapid screening of yeast adhesive properties for anti-fouling surfaces and a host of other applications.</div>

EFFECT OF SACCHAROMYCES CEREVISIAE LIVE YEAST CULTURE SUPPLEMENTATION ON TISSUE GLUTATHIONE VALUES IN RABBITS.

2019 ◽  
Vol 38 (2) ◽  
Author(s):  
Nurten GALIP ◽  
Nilay SEYIDOGLU ◽  
Zehra SERDAR ◽  
Nilgün Savaş ◽  
Merve Akyıldız
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Yeast Culture ◽  
Live Yeast

scholarly journals Linking gas and particle ejection dynamics to boundary conditions in scaled shock-tube experiments

2021 ◽  
Vol 83 (8) ◽  
Author(s):  
Valeria Cigala ◽  
Ulrich Kueppers ◽  
Juan José Peña Fernández ◽  
Donald B. Dingwell
Keyword(s):  
Particle Size ◽  
Shock Tube ◽  
Initial Conditions ◽  
Volcanic Eruptions ◽  
Tube Length ◽  
Experimental Investigations ◽  
Clear Correlation ◽  
Angular Deviation ◽  
Dynamic Nature ◽  
Experimental Conditions

AbstractPredicting the onset, style and duration of explosive volcanic eruptions remains a great challenge. While the fundamental underlying processes are thought to be known, a clear correlation between eruptive features observable above Earth’s surface and conditions and properties in the immediate subsurface is far from complete. Furthermore, the highly dynamic nature and inaccessibility of explosive events means that progress in the field investigation of such events remains slow. Scaled experimental investigations represent an opportunity to study individual volcanic processes separately and, despite their highly dynamic nature, to quantify them systematically. Here, impulsively generated vertical gas-particle jets were generated using rapid decompression shock-tube experiments. The angular deviation from the vertical, defined as the “spreading angle”, has been quantified for gas and particles on both sides of the jets at different time steps using high-speed video analysis. The experimental variables investigated are 1) vent geometry, 2) tube length, 3) particle load, 4) particle size, and 5) temperature. Immediately prior to the first above-vent observations, gas expansion accommodates the initial gas overpressure. All experimental jets inevitably start with a particle-free gas phase (gas-only), which is typically clearly visible due to expansion-induced cooling and condensation. We record that the gas spreading angle is directly influenced by 1) vent geometry and 2) the duration of the initial gas-only phase. After some delay, whose length depends on the experimental conditions, the jet incorporates particles becoming a gas-particle jet. Below we quantify how our experimental conditions affect the temporal evolution of these two phases (gas-only and gas-particle) of each jet. As expected, the gas spreading angle is always at least as large as the particle spreading angle. The latter is positively correlated with particle load and negatively correlated with particle size. Such empirical experimentally derived relationships between the observable features of the gas-particle jets and known initial conditions can serve as input for the parameterisation of equivalent observations at active volcanoes, alleviating the circumstances where an a priori knowledge of magma textures and ascent rate, temperature and gas overpressure and/or the geometry of the shallow plumbing system is typically chronically lacking. The generation of experimental parameterisations raises the possibility that detailed field investigations on gas-particle jets at frequently erupting volcanoes might be used for elucidating subsurface parameters and their temporal variability, with all the implications that may have for better defining hazard assessment.

scholarly journals Effect of the Process Parameters on the Adhesive Strength of Dissimilar Polymers Obtained by Multicomponent Injection Molding

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1039 ◽  
Author(s):  
Luciano Pisanu ◽  
Leonardo Costa Santiago ◽  
Josiane Dantas Viana Barbosa ◽  
Valter Estevão Beal ◽  
Marcio Luis Ferreira Nascimento
Keyword(s):  
Adhesive Strength ◽  
Natural Fiber ◽  
Fiber Composite ◽  
Pure Shear ◽  
Central Area ◽  
Dissimilar Materials ◽  
Type I ◽  
Coconut Fiber ◽  
Adhesive Properties ◽  
Experimental Conditions

The growing demand in the consumer market for products with sustainable technologies has motivated new applications using overmolded natural fiber composites. Therefore, studies have been conducted mainly to understand the adhesive properties of overmolded parts. In the present study, a polypropylene (PP) composite with 30% coconut fibers without additives was developed with the aid of a corotating twin screw extruder. Subsequently, a multicomponent injection mold was developed based on the geometry of the ISO 527 type I specimen, in which samples overmolded with PP and PP–coconut-fiber composite, with the overlap in the central area, were obtained to evaluate the adhesive strength of dissimilar materials. The objective of this study was to evaluate the bond between PP and PP–coconut-fiber composite under different processing conditions using an adhesive strength testing device to perform a pure shear analysis. The experimental conditions followed a statistical design considering four factors in two levels and a significance level of 5%. The results indicated that adhesive strength increased significantly as the overlap area increased. It was observed that temperature and injection flow rate were the factors that most contributed to strengthening the bonds of dissimilar materials.

scholarly journals VTC4 Polyphosphate Polymerase Knockout Increases Stress Resistance of Saccharomyces cerevisiae Cells

Biology ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 487
Author(s):  
Alexander Tomashevsky ◽  
Ekaterina Kulakovskaya ◽  
Ludmila Trilisenko ◽  
Ivan V. Kulakovskiy ◽  
Tatiana Kulakovskaya ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Heavy Metal ◽  
Stress Response ◽  
Stress Resistance ◽  
Alkaline Stress ◽  
Inorganic Polyphosphate ◽  
Divalent Metal Transporter ◽  
Metal Transporter ◽  
Elevated Expression ◽  
Chaperone Complex

Inorganic polyphosphate (polyP) is an important factor of alkaline, heavy metal, and oxidative stress resistance in microbial cells. In yeast, polyP is synthesized by Vtc4, a subunit of the vacuole transporter chaperone complex. Here, we report reduced but reliably detectable amounts of acid-soluble and acid-insoluble polyPs in the Δvtc4 strain of Saccharomyces cerevisiae, reaching 10% and 20% of the respective levels of the wild-type strain. The Δvtc4 strain has decreased resistance to alkaline stress but, unexpectedly, increased resistance to oxidation and heavy metal excess. We suggest that increased resistance is achieved through elevated expression of DDR2, which is implicated in stress response, and reduced expression of PHO84 encoding a phosphate and divalent metal transporter. The decreased Mg2+-dependent phosphate accumulation in Δvtc4 cells is consistent with reduced expression of PHO84. We discuss a possible role that polyP level plays in cellular signaling of stress response mobilization in yeast.

Evolution of ethylene by Saccharomyces cerevisiae as influenced by the carbon source for growth and the presence of air

1978 ◽  
Vol 24 (6) ◽  
pp. 637-642 ◽  
Author(s):  
K. C. Thomas ◽  
Mary Spencer
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Ethylene Production ◽  
Atp Synthesis ◽  
Yeast Cells ◽  
Yeast Culture ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Absolute Requirement ◽  
Wild Type Yeast

Effects of the carbon source and oxygen on ethylene production by the yeast Saccharomyces cerevisiae have been studied. The amounts of ethylene evolved by the yeast culture were less than those detected in the blank (an equal volume of uninoculated medium), suggesting a net absorption of ethylene by the yeast cells. Addition of glucose to the lactate-grown yeast culture induced ethylene production. This glucose-induced stimulation of ethylene production was inhibited to a great extent by cycloheximide. Results suggested that the yeast cells in the presence of glucose synthesized an ethylene precursor and passed it into the medium. The conversion of this precursor to ethylene might be stimulated by oxygen. The fact that ethylene was produced by the yeast growing anaerobically and also by respiration-deficient mutants isolated from the wild-type yeast suggested that mitochondrial ATP synthesis was not an absolute requirement for ethylene biogenesis.

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