Demonstration of Yeast Bud Scars With the Electron Microscope

Bartholomew, J. W.; Mittwer, Tod

doi:10.1128/jb.65.3.272-275.1953

Cited by 78 publications

(23 citation statements)

References 4 publications

(6 reference statements)

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“…Also, in senescence studies 5,15 , yeast cells are subject to morphological, metabolic and genetic modifications. Such modifications include an increase in size 6 and alterations to the shape and surface appearance of the cell 24 . The individual cell size alone does not control the cell's flocculation ability, but one would expect a relationship between the cell volume fraction and flocculation behavior as noted in equation 1 16 .…”

Section: Resultsmentioning

confidence: 99%

Effects of Fermentation Parameters and Cell Wall Properties on Yeast Flocculation¹

Speers

Wan

Jin³

et al. 2006

Journal of the Institute of Brewing

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Industrial wort was fermented with a NewFlo phenotype ale yeast in lab-scale cylindrical fermenters. The effects of various fermentation parameters and yeast cell wall properties on yeast flocculation were studied during 120 h fermentation. The evaluation of the cell volume during the fermentation revealed a non-normal distribution (p < 0.05) at most fermentation times. Overall yeast cell size initially decreased during the first 24 h of fermentation then increased during the 24-60 h fermentation period. Cell size subsequently declined until the end of fermentation presumably due to floc settling. While yeast flocculation began after 24 h fermentation, most flocs remained in suspension until 60 h when the average turbulent shear rate caused by CO 2 evolution declined to below 8 s -1 . Both the Helm's flocculence and cell surface hydrophobicity values rapidly increased to high numbers from 24 h onward. Changes in the orthokinetic capture coefficient (␣ 0 ) value with fermentation time, measured in fermenting worts, indicated a significant increase (p < 0.001) after 24 h of fermentation. Presumably, this change was due to increases in ethanol and the decline in sugar concentration with time. Although a significant positive correlation (p < 0.05) was observed between zymolectin densities and cell surface areas, the total zymolectin level on yeast cell walls did not change significantly with fermentation time (p > 0.05). Interestingly, no significant difference existed in Helm's flocculation values of suspended and settled yeast cells (p > 0.05). The flocculation rate of LCC125 was readily inhibited by addition of glucose or maltose. Results suggest that fermentable sugar levels and shear force exert major influences on yeast flocculation during beer fermentations.

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Section: Resultsmentioning

confidence: 99%

Effects of Fermentation Parameters and Cell Wall Properties on Yeast Flocculation¹

Speers

Wan

Jin³

et al. 2006

Journal of the Institute of Brewing

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“…Prior RLS studies have identified three common phenotypes associated with cellular aging (28,29). In budding yeast, aging mother cells increase in cell size, progressively slow their doubling times, and produce daughters with decreased fitness (5)(6)(7) . Whether older fission yeast cells also undergo similar aging-associated phenotypes remained unresolved.…”

Section: Aging-associated Phenotypes Do Not Correlate With Death In Fmentioning

confidence: 99%

“…In budding yeast, asymmetric division into mother and daughter cells ensures that a mother cell produces a limited number of daughters over its replicative lifespan (RLS) (5). Aging mother cells increase in size, divide progressively more slowly, and produce shorter-lived daughters (5)(6)(7). Mother cell decline is associated with asymmetric phenotypes such as preferential retention of protein aggregates, dysregulation of vacuole acidity, and genomic instability (3,8,9).…”

Section: Introductionmentioning

confidence: 99%

An aging-independent replicative lifespan in a symmetrically dividing eukaryote

Spivey

Jones

Rybarski

et al. 2016

Preprint

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The replicative lifespan (RLS) of a cell-defined as the number of cell divisions before death-has informed our understanding of the mechanisms of cellular aging. However, little is known about aging and longevity in symmetrically dividing eukaryotic cells because most prior studies have used budding yeast for RLS studies. Here, we describe a multiplexed fission yeast lifespan micro-dissector (multFYLM) and an associated image processing pipeline for performing high-throughput and automated single-cell micro-dissection. Using the multFYLM, we observe continuous replication of hundreds of individual fission yeast cells for over seventy-five generations. Surprisingly, cells die without the classic hallmarks of cellular aging, such as progressive changes in size, doubling time, or sibling health. Genetic perturbations and drugs can extend the RLS via an aging-independent mechanism. Using a quantitative model to analyze these results, we conclude that fission yeast does not age and that cellular aging and replicative lifespan can be uncoupled in a eukaryotic cell.

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“…Studies of the ageing phenotype in both haploid laboratory strains and polyploid brewing strains have indicated that as a consequence of senescence yeast cells are subject to morphological, metabolic and genetic modi¢cations [1]. Such modi¢cations include an increase in size [2] and alterations to the shape and surface appearance of the cell [3]. In addition, generation time is altered [3], metabolism declines [4] and gene expression [5] and protein synthesis [4] become modi¢ed.…”

Section: Introductionmentioning

confidence: 99%

The impact of brewing yeast cell age on fermentation performance, attenuation and flocculation

Powell

Quain²,

Smart

2003

FEMS Yeast Research

119

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Individual cells of the yeast Saccharomyces cerevisiae exhibit a finite replicative lifespan, which is widely believed to be a function of the number of divisions undertaken. As a consequence of ageing, yeast cells undergo constant modifications in terms of physiology, morphology and gene expression. Such characteristics play an important role in the performance of yeast during alcoholic beverage production, influencing sugar uptake, alcohol and flavour production and also the flocculation properties of the yeast strain. However, although yeast fermentation performance is strongly influenced by the condition of the yeast culture employed, until recently cell age has not been considered to be important to the process. In order to ascertain the effect of replicative cell age on fermentation performance, age synchronised populations of a lager strain were prepared using sedimentation through sucrose gradients. Each age fraction was analysed for the ability to utilise fermentable sugars and the capacity to flocculate. In addition cell wall properties associated with flocculation were determined for cells within each age fraction. Aged cells were observed to ferment more efficiently and at a higher rate than mixed aged or virgin cell cultures. Additionally, the flocculation potential and cell surface hydrophobicity of cells was observed to increase in conjunction with cell age. The mechanism of ageing and senescence in brewing yeast is a complex process, however here we demonstrate the impact of yeast cell ageing on fermentation performance.

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Demonstration of Yeast Bud Scars With the Electron Microscope

Cited by 78 publications

References 4 publications

Effects of Fermentation Parameters and Cell Wall Properties on Yeast Flocculation¹

Effects of Fermentation Parameters and Cell Wall Properties on Yeast Flocculation¹

An aging-independent replicative lifespan in a symmetrically dividing eukaryote

The impact of brewing yeast cell age on fermentation performance, attenuation and flocculation

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Demonstration of Yeast Bud Scars With the Electron Microscope

Cited by 78 publications

References 4 publications

Effects of Fermentation Parameters and Cell Wall Properties on Yeast Flocculation1

Effects of Fermentation Parameters and Cell Wall Properties on Yeast Flocculation1

An aging-independent replicative lifespan in a symmetrically dividing eukaryote

The impact of brewing yeast cell age on fermentation performance, attenuation and flocculation

Contact Info

Product

Resources

About

Effects of Fermentation Parameters and Cell Wall Properties on Yeast Flocculation¹

Effects of Fermentation Parameters and Cell Wall Properties on Yeast Flocculation¹