scholarly journals The Influence of the Concentration of Calcium Ions on the Comparative Absorption of Metallic Ions by the Yeast Cells and on the Yeast Growth

CYTOLOGIA ◽  
1958 ◽  
Vol 23 (1) ◽  
pp. 9-13
Author(s):  
Krishna Bahadur ◽  
Harish Chandra Verma
Keyword(s):  
Calcium Ions ◽  
Yeast Cells ◽  
Metallic Ions ◽  
Yeast Growth

AMINO ACID TRANSPORT IN YEAST AND EFFECTS OF NYSTATIN

1963 ◽  
Vol 41 (1) ◽  
pp. 397-407 ◽  
Author(s):  
E. Stachiewicz ◽  
J. H. Quastel
Keyword(s):  
Fatty Acids ◽  
Amino Acid ◽  
Calcium Ions ◽  
Amino Acid Transport ◽  
Protective Action ◽  
Yeast Cells ◽  
Acid Transport ◽  
Free Medium ◽  
Complete Protection ◽  
Normal Cells

Nystatin, an antifungal antibiotic, inhibits the accumulation, by yeast cells, of glycine, leucine, arginine, and alanine at concentrations that have no effect on the respiration of the cells. The uptake of glycine by yeast cells that have been preincubated with nystatin and then suspended in a nystatin-free medium is much lower than that of normal cells. The longer the preincubation with nystatin, the greater is the inhibition of glycine uptake. Nystatin produces two distinct effects. At concentrations below 0.8 μg/ml, nystatin inhibits glycine or arginine uptake. At concentrations from 0.8 to 2.0 μg/ml, it causes an efflux of previously accumulated glycine or arginine. Fatty acids, such as oleic, linoleic, stearic, or palmitic acid, can protect the yeast cell from the action of nystatin. The presence of citrate or versene abolishes the protective action of these fatty acids. Calcium ions also protect the cell from the action of nystatin. The concentration of calcium ions giving complete protection depends upon the nystatin concentration. The implications of these facts on amino acid transport in yeast are discussed.

scholarly journals Deletion of the trehalose tps1 gene in Kluyveromyces lactis does not impair growth in glucose

2020 ◽  
Vol 367 (10) ◽  
Author(s):  
Antonio M V Gomes ◽  
Ana Carolina A L Orlandi ◽  
Nádia S Parachin
Keyword(s):  
Dairy Products ◽  
Gene Disruption ◽  
Sole Carbon Source ◽  
Gene Deletion ◽  
Kluyveromyces Lactis ◽  
Growth Failure ◽  
Yeast Cells ◽  
Yeast Growth ◽  
Tps1 Gene ◽  
Encoding Gene

ABSTRACT Trehalose is a non-reducing disaccharide composed of two α-glucose molecules and synthesized by an enzyme complex containing four subunits TPS1 (EC 2.4.1.15), TPS2 (EC 3.1.3.12), TPS3 and TSL1. First reports about trehalose classified this sugar as an energy reserve compound like glycogen. However, lately, trehalose is known to assist yeast cells during heat, osmotic and starvation stresses. In Saccharomyces cerevisiae, the deletion of the tps1 encoding gene eliminated the yeast ability to grow on glucose as the sole carbon source. Kluyveromyces lactis is a yeast present in various dairy products and is currently utilized for the synthesis of more than 40 industrial heterologous products. In this study, the deletion of the tps1 gene in K. lactis showed that unlike S. cerevisiae, tps1 gene disruption does not cause growth failure in glucose, galactose, or fructose. The µMAX rate values of K. lactis tps1Δ strains were equal than the non-disrupted strains, showing that the gene deletion does not affect the yeast growth. After gene disruption, the absence of trehalose into the metabolism of K. lactis was also confirmed.

Enhancement of bifidobacteria survival by Williopsis saturnus var. saturnus in milk

2016 ◽  
Vol 7 (1) ◽  
pp. 135-144 ◽  
Author(s):  
A.Y.Y. Yeo ◽  
M.Z. Toh ◽  
S.Q. Liu
Keyword(s):  
Viable Cell ◽  
Oxygen Removal ◽  
Physical Contact ◽  
Yeast Cells ◽  
Yeast Growth ◽  
Bifidobacterium Lactis ◽  
Enhancing Effect ◽  
Uht Milk ◽  
Williopsis Saturnus ◽  
Dairy Beverages

The viability of three strains of probiotic Bifidobacterium lactis that were inoculated into UHT milk was examined with and without the presence of the yeast, Williopsis saturnus var. saturnus NCYC 22, in polypropylene tubes at 30 °C. The B. lactis viable cell count for strains HN019 and BB-12 remained above 6.0 Log cfu/ml, while strain B94 had 5.7 Log cfu/ml after six weeks of incubation in the presence of the co-inoculated yeast. Incubating the bifidus milk without added yeast under anaerobic condition did not improve the survival of B. lactis HN019, indicating that oxygen removal may not be responsible for W. saturnus NCYC 22’s viability enhancing property. The addition of yeast supernatant or non-viable yeast also did not show any stabilising effects, suggesting that physical contact and/or interaction between viable W. saturnus and B. lactis plays an important role in sustaining the viability of the probiotic. W. saturnus NCYC 22 could increase the survival of B. lactis in bifidus milk under ambient temperature regardless of the initial concentration of yeast cells inoculated due to yeast growth. This study demonstrated the viability enhancing effect of viable W. saturnus NCYC 22 on B. lactis HN019, which could help towards extending the shelf-life of dairy beverages containing probiotic bifidobacteria.

The stimulation of yeast growth and respiration by compounds produced by yeast cells irradiated with ultraviolet light

1952 ◽  
Vol 40 (2) ◽  
pp. 269-278 ◽  
Author(s):  
S. James Adelstein ◽  
Falls B. Hershey ◽  
John R. Loofbourow ◽  
Irwin W. Sizer
Keyword(s):  
Ultraviolet Light ◽  
Yeast Cells ◽  
Yeast Growth ◽  
Stimulation Of

Legume vicilins (7S storage globulins) inhibit yeast growth and glucose stimulated acidification of the medium by yeast cells

1998 ◽  
Vol 1379 (2) ◽  
pp. 207-216 ◽  
Author(s):  
Valdirene M Gomes ◽  
Lev A Okorokov ◽  
Tatiana L Rose ◽  
Kátia Valevski S Fernandes ◽  
José Xavier-Filho
Keyword(s):  
Yeast Cells ◽  
Yeast Growth

scholarly journals Fission Yeast Cells Grow Approximately Exponentially

2018 ◽  
Author(s):  
Mary Pickering ◽  
Lauren Nicole Hollis ◽  
Edridge D’Souza ◽  
Nicholas Rhind
Keyword(s):  
Cell Cycle ◽  
Cell Growth ◽  
Fission Yeast ◽  
Cell Size ◽  
Exponential Growth ◽  
Cell Biology ◽  
Growth Models ◽  
Growth Period ◽  
Yeast Cells ◽  
Yeast Growth

ABSTRACTHow the rate of cell growth is influenced by cell size is a fundamental question of cell biology. The simple model that cell growth is proportional to cell size, based on the proposition that larger cells have proportionally greater synthetic capacity than smaller cells, leads to the predication that the rate of cell growth increases exponentially with cell size. However, other modes of cell growth, including bilinear growth, have been reported. The distinction between exponential and bilinear growth has been explored in particular detail in the fission yeast Schizosaccharomyces pombe. We have revisited the mode of fission yeast cell growth using high-resolution time-lapse microscopy and find, as previously reported, that these two growth models are difficult to distinguish both because of the similarity in shapes between exponential and bilinear curves over the two-fold change in length of a normal cell cycle and because of the substantial biological and experimental noise inherent to these experiments. Therefore, we contrived to have cells grow more than two fold, by holding them in G2 for up to eight hours. Over this extended growth period, in which cells grow up to 5.5-fold, the two growth models diverge to the point that we can confidently exclude bilinear growth as a general model for fission yeast growth. Although the growth we observe is clearly more complicated than predicted by simple exponential growth, we find that exponential growth is a robust approximation of fission yeast growth, both during an unperturbed cell cycle and during extended periods of growth.

AMINO ACID TRANSPORT IN YEAST AND EFFECTS OF NYSTATIN

1963 ◽  
Vol 41 (2) ◽  
pp. 397-407 ◽  
Author(s):  
E. Stachiewicz ◽  
J. H. Quastel
Keyword(s):  
Fatty Acids ◽  
Amino Acid ◽  
Calcium Ions ◽  
Amino Acid Transport ◽  
Protective Action ◽  
Yeast Cells ◽  
Acid Transport ◽  
Free Medium ◽  
Complete Protection ◽  
Normal Cells

Nystatin, an antifungal antibiotic, inhibits the accumulation, by yeast cells, of glycine, leucine, arginine, and alanine at concentrations that have no effect on the respiration of the cells. The uptake of glycine by yeast cells that have been preincubated with nystatin and then suspended in a nystatin-free medium is much lower than that of normal cells. The longer the preincubation with nystatin, the greater is the inhibition of glycine uptake. Nystatin produces two distinct effects. At concentrations below 0.8 μg/ml, nystatin inhibits glycine or arginine uptake. At concentrations from 0.8 to 2.0 μg/ml, it causes an efflux of previously accumulated glycine or arginine. Fatty acids, such as oleic, linoleic, stearic, or palmitic acid, can protect the yeast cell from the action of nystatin. The presence of citrate or versene abolishes the protective action of these fatty acids. Calcium ions also protect the cell from the action of nystatin. The concentration of calcium ions giving complete protection depends upon the nystatin concentration. The implications of these facts on amino acid transport in yeast are discussed.

scholarly journals Inhibition of Respiratory Growth and Survival in Yeast by Dopamine and Counteraction with Ascorbate or Glutathione

2010 ◽  
Vol 15 (3) ◽  
pp. 297-301 ◽  
Author(s):  
Ian G. Macreadie ◽  
Nick Bartone ◽  
Lindsay Sparrow
Keyword(s):  
Reactive Oxygen Species ◽  
Respiratory Function ◽  
Mammalian Cells ◽  
Reactive Oxygen ◽  
Yeast Cells ◽  
Oxygen Species ◽  
Inhibitory Effects ◽  
Yeast Growth ◽  
Growth And Survival ◽  
Convenient Model

Dopamine is a key monamine neurotransmitter, yet it can also exhibit toxicity to neuronal cells. There are suggestions that dopamine may be neurotoxic due to its propensity to induce the formation of reactive oxygen species, which may in turn adversely affect mitochondrial function and cell viability. In this study, the effects of dopamine or a dopamine reaction product on yeast growth and survival have been explored. Yeast is ideal for such a study because, unlike mammalian cells, yeast cells can be grown even when respiratory function is totally absent. Indeed, dopamine was found to be inhibitory to yeast growth in media where respiratory function was required and cytotoxic to yeast cells suspended in water. The inhibitory effects of dopamine were reduced greatly by the antioxidants ascorbate and glutathione, suggesting the involvement of reactive oxygen species in dopamine-mediated toxicity. It would appear that yeast may offer a convenient model to perform screens for further compounds that may provide protection against dopamine-mediated growth inhibition and toxicity.

scholarly journals Ralstonia solanacearum Type III Effector RipAY Is a Glutathione-Degrading Enzyme That Is Activated by Plant Cytosolic Thioredoxins and Suppresses Plant Immunity

mBio ◽  
2016 ◽  
Vol 7 (2) ◽  
Author(s):  
Takafumi Mukaihara ◽  
Tadashi Hatanaka ◽  
Masahito Nakano ◽  
Kenji Oda
Keyword(s):  
Immune System ◽  
Ralstonia Solanacearum ◽  
Plant Immunity ◽  
Plant Cells ◽  
Effector Proteins ◽  
Yeast Cells ◽  
Yeast Growth ◽  
Type Iii Effector ◽  
Plant Immune System ◽  
Degradation Activity

ABSTRACT The plant pathogen Ralstonia solanacearum uses a large repertoire of type III effector proteins to succeed in infection. To clarify the function of effector proteins in host eukaryote cells, we expressed effectors in yeast cells and identified seven effector proteins that interfere with yeast growth. One of the effector proteins, RipAY, was found to share homology with the ChaC family proteins that function as γ-glutamyl cyclotransferases, which degrade glutathione (GSH), a tripeptide that plays important roles in the plant immune system. RipAY significantly inhibited yeast growth and simultaneously induced rapid GSH depletion when expressed in yeast cells. The in vitro GSH degradation activity of RipAY is specifically activated by eukaryotic factors in the yeast and plant extracts. Biochemical purification of the yeast protein identified that RipAY is activated by thioredoxin TRX2. On the other hand, RipAY was not activated by bacterial thioredoxins. Interestingly, RipAY was activated by plant h -type thioredoxins that exist in large amounts in the plant cytosol, but not by chloroplastic m -, f -, x -, y - and z -type thioredoxins, in a thiol-independent manner. The transient expression of RipAY decreased the GSH level in plant cells and affected the flg22-triggered production of reactive oxygen species (ROS) and expression of pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) marker genes in Nicotiana benthamiana leaves. These results indicate that RipAY is activated by host cytosolic thioredoxins and degrades GSH specifically in plant cells to suppress plant immunity. IMPORTANCE Ralstonia solanacearum is the causal agent of bacterial wilt disease of plants. This pathogen injects virulence effector proteins into host cells to suppress disease resistance responses of plants. In this article, we report a biochemical activity of R. solanacearum effector protein RipAY. RipAY can degrade GSH, a tripeptide that plays important roles in the plant immune system, with its γ-glutamyl cyclotransferase activity. The high GSH degradation activity of RipAY is considered to be a good weapon for this bacterium to suppress plant immunity. However, GSH also plays important roles in bacterial tolerance to various stresses and growth. Interestingly, RipAY has an excellent safety mechanism to prevent unwanted firing of its enzyme activity in bacterial cells because RipAY is specifically activated by host eukaryotic thioredoxins. This study also reveals a novel host plant protein acting as a molecular switch for effector activation.

scholarly journals Systematic Investigation of Ergosterol Fermentation by Kluyveromyces marxianus Y.00243 via Statistical Design

2021 ◽  
Author(s):  
Aladár Vidra ◽  
Zoltán Kaleta ◽  
Áron Németh
Keyword(s):  
Salt Concentration ◽  
Kluyveromyces Marxianus ◽  
Biomass Concentration ◽  
Statistical Design ◽  
Structural Features ◽  
Systematic Investigation ◽  
Yeast Cells ◽  
Yeast Growth ◽  
Ergosterol Content ◽  
Negative Effect

Ergosterol, an important pharmaceutical intermediate, is the precursor of liposoluble vitamin D2 and cortisone. It is also a main sterol in yeast cells and responsible for structural features of membranes such as the integrity, fluidity, permeability and activity of membrane-bound enzymes. Kluyveromyces marxianus is able to utilize various sugars such as lactose, xylose and arabinose against Saccharomyces cerevisiae and is also thermotolerant. Based on these aforementioned characteristics, K. marxianus can be of great importance in the utilization of whey and lignocellulosic biomass. In this paper, the effect of four factors on the specific ergosterol content and yeast growth was investigated using two statistical experimental designs. The factors examined were initially added alcohol, temperature, salt concentration and pH. The initially added alcohol had a positive effect on the specific ergosterol content, resulted in 37 % specific ergosterol content increasement. The temperature had a negative effect on yeast growth reducing the biomass concentration by 50 % when increased from 25 °C to 30 °C. The pH had a significant effect only on the specific ergosterol content, having an optimum at pH 5.5. The salt concentration had no significant effect in either case. Based on the results, it is suggested that the setup which facilitates higher ergosterol content but does not slow down the growth of the yeast remarkably should be selected, which are 25 °C, pH 5.3 and 3 % of initial ethanol content.

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