scholarly journals Changes in the transport of mitochondrial Ca2+ during the culture growth cycle of Tetrahymena pyriformis

1985 ◽  
Vol 77 (1) ◽  
pp. 47-56
Author(s):  
Y.V. Kim ◽  
LYu Kudzina ◽  
V.P. Zinchenko ◽  
Y.V. Evtodienko
Keyword(s):  
Stationary Phase ◽  
Morphological Changes ◽  
Stationary Phases ◽  
Mitochondrial Protein ◽  
Tetrahymena Pyriformis ◽  
Growth Cycle ◽  
Lag Phase ◽  
Rapid Release ◽  
Culture Growth ◽  
Energy Dependent

The properties of the Ca2+ transport system of mitochondria, isolated in various phases of growth of static cultures of Tetrahymena pyriformis, were studied. A large increase in the endogenous energy-dependent Ca2+ content of mitochondria was observed as cultures of T. pyriformis passed through the exponential and stationary phases of growth (approx. 0.25 and 50 nmol Ca2+ per mg mitochondrial protein, respectively). Simultaneously, the mitochondria dramatically lost their ability to withstand large concentrations of Ca2+ and ADP. However, in the latter case they were able to phosphorylate a large amount of ADP if the strong Ca2+ chelator, ethylene glycol bis-(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid, was initially present in the incubation medium. Furthermore, all the changes observed in mitochondria from the stationary phase cells were completely reversed when cell proliferation was re-activated after the lag phase, either by reseeding the stationery cells in fresh growth medium or by oxygenation of the old medium. In aerobic conditions even a small addition of Ca2+ was able to induce rapid release of Ca2+ from mitochondria isolated during the stationary phase of growth. It is suggested that the redistribution of Ca2+ between the mitochondria and the cytoplasm at the onset of the lag phase may serve as the main trigger for the subsequent biochemical and morphological changes observed in T. pyriformis.

Associations Between Cellular Levels of ATP and Prodigiosin Pigment Throughout the Growth Cycle of Serratia marcescens

2021 ◽  
Author(s):  
Pryce L. Haddix
Keyword(s):  
Stationary Phase ◽  
Serratia Marcescens ◽  
Stationary Phases ◽  
Growth Cycle ◽  
High Density ◽  
High Rate ◽  
Lag Phase ◽  
Positive Role ◽  
Atp Production ◽  
Density Growth

ABSTRACT Serratia marcescens is a prolific producer of the red, membrane-associated pigment prodigiosin. Earlier work has established both a positive role for prodigiosin in ATP production during population lag phase and a negative role during high-rate, low cell density growth. This study uses the growth rate and growth phase modulation afforded by chemostat culture to extend prodigiosin functional analysis to the high density and stationary phases. Cellular levels of prodigiosin were positively associated with cellular levels of ATP during high-density growth, and artificial pigment induction during this phase increased cellular ATP. Following peak high density ATP per cell, early stationary phase enabled significant population growth while prodigiosin levels remained high and ATP declined. During late stationary phase, ATP per cell was positively associated with prodigiosin per cell while both declined during continued growth. These results provide correlational evidence for multiple effects of prodigiosin pigment on ATP production throughout the growth cycle. Earlier work and the data presented here enable formulation of a working model for the oscillating relationships between cellular levels of ATP and prodigiosin during batch culture.

scholarly journals NUCLEOLAR AND BIOCHEMICAL CHANGES DURING UNBALANCED GROWTH OF TETRAHYMENA PYRIFORMIS

1965 ◽  
Vol 26 (3) ◽  
pp. 845-855 ◽  
Author(s):  
Ivan L. Cameron ◽  
E. Ernest Guile
Keyword(s):  
Protein Synthesis ◽  
Stationary Phase ◽  
Rna Synthesis ◽  
Morphological Changes ◽  
Synthetic Medium ◽  
Tetrahymena Pyriformis ◽  
Lag Phase ◽  
Proteose Peptone ◽  
Rna And Protein Synthesis ◽  
Peptone Medium

Numerous nucleoli can be observed in the macronucleus of the logarithmically growing ciliated protozoan Tetrahymena pyriformis; at late log phase the nucleoli aggregate and fuse. In stationary phase this fusion process continues, leaving a very few large vacuolated nuclear fusion bodies in the nucleus. When these stationary phase cells are placed into fresh enriched proteose peptone medium, the large fusion bodies begin to disaggregate during the 2.5-hour lag phase before cell division is initiated. By 3 to 6 hours after inoculation the appearance of the nucleoli in many cells returns to what it was in logarithmic cells. In view of the possible role of nucleoli in ribosome synthesis, attempts were made to correlate the morphological changes to changes in RNA and protein metabolism. The beginning of an increased RNA synthesis was concomitant with the beginning of disaggregation of the large fusion bodies into nucleoli, which was noticed in some cells by 1 hour after the return to fresh enriched proteose peptone medium. Increased protein synthesis then followed the increased RNA synthesis by 1 hour. The supply of RNA precursors (essential pyrimidines) were removed from cultures which were grown on a chemically defined synthetic medium, in order to study the relation between nucleolar fusion and synthesis of RNA and protein. Pyrimidine deprivation drastically curtailed RNA and protein synthesis, but did not cause fusion of nucleoli. When pyrimidines were added back to this culture medium, RNA synthesis was immediately stimulated and again preceded an increased protein synthesis by 1 hour. These studies suggest the involvement of unfused nucleoli in RNA and protein synthesis and demonstrate the extreme plasticity of nucleoli with respect to changes in their environment.

GROWTH STUDIES ON ARTHROBACTER GLOBIFORMIS: II. CHANGES IN MACROMOLECULAR LEVELS DURING GROWTH

1962 ◽  
Vol 8 (5) ◽  
pp. 655-661 ◽  
Author(s):  
I. L. Stevenson
Keyword(s):  
Stationary Phase ◽  
Fold Increase ◽  
Growth Cycle ◽  
Phase Cell ◽  
Lag Phase ◽  
Differential Rate ◽  
Protein Ratio ◽  
Stationary Phase Culture ◽  
Protein Levels ◽  
Dna And Protein Synthesis

Changes in macromolecular levels (RNA, DNA, protein) have been followed during the growth cycle of A. globiformis. When a stationary phase culture is transferred to fresh medium a 12-fold increase in RNA level and 6-fold increases in DNA and protein levels are observed during the predivisional lag phase. Initially RNA synthesis precedes DNA and protein synthesis but all reach the same differential rate 2 to 3 hours prior to division. During the predivisional lag period the RNA/protein ratio per cell expands from 0.19 to 0.36. Once division occurs, cells of A. globiformis remain in the enlarged pleomorphic form until the medium becomes limiting; at this time synthesis of macromolecules ceases and the continued division (three to four generations) results in progressively smaller cells until the coccoid stationary phase cell-type is reached.

Morphological changes during the growth cycle of axenic and monoxenic Tetrahymena pyriformis

1976 ◽  
Vol 54 (11) ◽  
pp. 2011-2018 ◽  
Author(s):  
William D. Taylor ◽  
Michael A. Gates ◽  
Jacques Berger
Keyword(s):  
Culture Media ◽  
Morphological Changes ◽  
Food Limitation ◽  
Food Resource ◽  
Tetrahymena Pyriformis ◽  
Growth Cycle ◽  
Exponential Phase ◽  
Type Ii ◽  
Axenic Medium ◽  
Morphological Differences

Morphometric data were collected from Tetrahymena pyriformis (WH-14, syngen I, mating type II) grown in two different media, one axenic and one monoxenic (with Serratia marcescens), at various times during the growth cycle. Stationary phase cells differed morphometrically from exponential phase cells in different ways in the two media. It is proposed that, in the monoxenic medium, division stopped because the food resource was depleted, while in the axenic medium division was blocked before food limitation occurred.Cells in the two culture media showed consistent morphological differences during exponential phase, the axenic cells being larger (length and width), but having smaller (in length) mouths. Significant differences between cells in replicate experiments were frequently observed.

The relationship of cardiolipin biosynthesis to mitochondrial protein synthesis in Tetrahymena pyriformis

1983 ◽  
Vol 61 (4) ◽  
pp. 223-228 ◽  
Author(s):  
Sean M. Hemmingsen ◽  
Laura Querengesser ◽  
Paul G. Young
Keyword(s):  
Protein Synthesis ◽  
Stationary Phase ◽  
Mitochondrial Protein ◽  
Tetrahymena Pyriformis ◽  
Pulse Labelling ◽  
Mitochondrial Protein Synthesis ◽  
Mole Percent ◽  
Quantitative Measurements ◽  
Relationship Of ◽  
The Relationship

The synthesis of cardiolipin has been investigated following the inhibition of mitochondrial protein synthesis with chloramphenicol. Quantitative measurements of the amount of cardiolipin in the cell during treatment with chloramphenicol as well as pulse-labelling studies using labelled acetate were carried out. The results show that while whole cell phospholipid biosynthesis is depressed by the treatment (probably a reflection of a general cessation of growth), there is no sign of any preferential effect on cardiolipin synthesis. The data also show that as cells are reduced in size as they approach stationary phase there is a six- to seven-fold loss of total cellular phospholipids; however, the amount of cardiolipin is only reduced by four- to five-fold. There is a preferential conservation of cardiolipin as stationary phase is approached with the mole percent cardiolipin phosphorus in the cell rising from 5–7% to 10–12%.

Changes of trehalose content and expression of relative genes during the bioethanol fermentation bySaccharomyces cerevisiae

2016 ◽  
Vol 62 (10) ◽  
pp. 827-835 ◽  
Author(s):  
Chenfeng Yi ◽  
Fenglian Wang ◽  
Shijun Dong ◽  
Hao Li
Keyword(s):  
Phase Transition ◽  
Stationary Phase ◽  
Ethanol Tolerance ◽  
Stationary Phases ◽  
Exponential Phase ◽  
Yeast Cells ◽  
Ethanol Stress ◽  
Lag Phase ◽  
Significant Difference ◽  
Trehalose Content

Traditionally, trehalose is considered as a protectant to improve the ethanol tolerance of Saccharomyces cerevisiae. In this study, to clarify the changes and roles of trehalose during the bioethanol fermentation, trehalose content and expression of related genes at lag, exponential, and stationary phases (i.e., 2, 8, and 16 h of batch fermentation process) were determined. Although yeast cells at exponential and stationary phase had higher trehalose content than cells at lag phase (P < 0.01), there was no significant difference in trehalose content between exponential and stationary phases (P > 0.05). Moreover, expression of the trehalose degradation-related genes NTH1 and NTH2 decreased at exponential phase in comparison with that at lag phase; compared with cells at lag phase, cells at stationary phase had higher expression of TPS1, ATH1, NTH1, and NTH2 but lower expression of TPS2. During the lag–exponential phase transition, downregulation of NTH1 and NTH2 promoted accumulation of trehalose, and to some extent, trehalose might confer ethanol tolerance to S. cerevisiae before stationary phase. During the exponential–stationary phase transition, upregulation of TPS1 contributed to accumulation of trehalose, and Tps1 protein might be indispensable in yeast cells to withstand ethanol stress at the stationary phase. Moreover, trehalose would be degraded to supply carbon source at stationary phase.

Regulation of RNA synthesis in Tetrahymena pyriformis: secretion of regulatory factors

1979 ◽  
Vol 35 (1) ◽  
pp. 17-24
Author(s):  
H.A. Andersen ◽  
S.J. Nielsen
Keyword(s):  
Stationary Phase ◽  
Ribosomal Rna ◽  
Rna Synthesis ◽  
Initial Rate ◽  
Tetrahymena Pyriformis ◽  
Dose Effect ◽  
Exponential Growth Phase ◽  
Lag Phase ◽  
Cell Densities ◽  
Phase Population

The rate of ribosomal RNA synthesis varies greatly with the population density in both exponentially and synchronously growing populations of Tetrahymena pyriformis. Shortly after inoculation of the population - at relatively low cell densities - a gene-dose effect dominates the picture, and a doubling in the gene number is immediately followed by a doubling in the rate of RNA synthesis. However, also other mechanisms are controlling the rate of RNA synthesis. Generally one finds high rates of RNA synthesis in the lag phase of newly inoculated cells, decreasing rate of RNA synthesis during most of the exponential growth phase and very low rate of synthesis in stationary phase cells. We now have results which show that the repression of RNA synthesis in densely populated cultures is caused by a dialysable factor, which is secreted by the cells. If cells are inoculated on a medium which contains this factor the high initial rate of RNA synthesis normally observed is prevented, but the cells multiply and grow with normal generation time until normal stationary-phase population densities are reached.

scholarly journals Inositol transport in Saccharomyces cerevisiae is regulated by transcriptional and degradative endocytic mechanisms during the growth cycle that are distinct from inositol-induced regulation.

1996 ◽  
Vol 7 (1) ◽  
pp. 81-89 ◽  
Author(s):  
K S Robinson ◽  
K Lai ◽  
T A Cannon ◽  
P McGraw
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Stationary Phase ◽  
Exponential Growth ◽  
Growth Cycle ◽  
Endocytic Pathway ◽  
Negative Regulator ◽  
Lag Phase ◽  
Free Medium ◽  
Uptake Activity ◽  
Inositol Uptake

Regulation of inositol uptake activity in Saccharomyces cerevisiae during the growth cycle was examined. Activity increased as the cell population transited from lag phase to exponential growth, and continued to increase until late exponential phase. The increase in activity was due to increased transcription of the ITR1 gene and synthesis of the Itr1 permease. When the culture reached stationary phase, uptake activity decreased and dropped to a minimum within 4 h. The decrease was due to repression of ITR1 transcription, independent of the negative regulator Opi1p, and degradation of the existing permease. Degradation depended on delivery of the permease to the vacuole through the END3/END4 endocytic pathway. During exponential growth in inositol-containing medium the permease is also rapidly degraded, whereas in inositol-free medium the permease is highly stable. Rapid degradation of the permease at stationary phase occurred in inositol-free medium, indicating that there are two distinct mechanisms that trigger endocytosis and degradation in response to different physiological stimuli. In addition, the level of the enzyme required for inositol biosynthesis, inositol-1-phosphate synthase, encoded by INO1, is not reduced in stationary-phase cells, and this contrast in the regulation of inositol supply is discussed.

scholarly journals NUCLEOLAR AGING IN TETRAHYMENA DURING THE CULTURAL GROWTH CYCLE

1971 ◽  
Vol 48 (1) ◽  
pp. 143-154 ◽  
Author(s):  
Birgit Satir ◽  
Ellen Roter Dirksen
Keyword(s):  
Stationary Phase ◽  
Actinomycin D ◽  
Nuclear Periphery ◽  
Tetrahymena Pyriformis ◽  
Growth Cycle ◽  
Growth Phases ◽  
Stage 4 ◽  
The Individual ◽  
Stage 1 ◽  
Logarithmic Growth

Nucelolar morphology was studied by electron microscopy in control and actinomycin D-treated populations of Tetrahymena pyriformis (W) during the cultural growth cycle. Nucleoli exhibit an "aging" cycle concomitant with the cultural growth cycle, but independent of the individual cell cycle. Four different stages in the course of this aging process have been defined. Stage 1 occurs upon inoculation (low number of cells per milliliter) and lasts through lag and accelerating growth phases. In this stage, many small nucleoli are found at the nuclear periphery. In stages 2 and 3, nucleolar fusion begins. Stage 2 dominates the first half of logarithmic growth, and stage 3 dominates the second half. In late decelerating growth phase, the nucleoli enter stage 4. In this stage, only a few large nucleoli are present and these are apparently inactive in ribosome production. In stationary phase, where total RNA remains constant, only stage 4 nucleoli are present. The relative preponderance of granular vs. fibrous components in the nucleoli changes during this cycle, the granular component dominating stage 1 nucleoli and the fibrillar, stage 4 nucleoli. There is a shortening of the intermediate nucleolar stages in the treated cultures; fusion occurs early and is now pronounced. Not enough ribosomes accumulate to carry the treated cultures through the number of generations equivalent to those of the control, which produces a premature stationary phase.

scholarly journals Temporal Analysis of Coxiella burnetii Morphological Differentiation

2004 ◽  
Vol 186 (21) ◽  
pp. 7344-7352 ◽  
Author(s):  
Sherry A. Coleman ◽  
Elizabeth R. Fischer ◽  
Dale Howe ◽  
David J. Mead ◽  
Robert A. Heinzen
Keyword(s):  
Stationary Phase ◽  
Coxiella Burnetii ◽  
Time Course ◽  
Growth Cycle ◽  
Cycle Phase ◽  
Lag Phase ◽  
Developmental Cycle ◽  
Phase Lag ◽  
Electron Microscopic ◽  
Transmission Electron

ABSTRACT Coxiella burnetii undergoes a poorly defined developmental cycle that generates morphologically distinct small-cell variants (SCV) and large-cell variants (LCV). We developed a model to study C. burnetii morphogenesis that uses Vero cells synchronously infected with homogeneous SCV (Nine Mile strain in phase II) harvested from aged infected cell cultures. A time course transmission electron microscopic analysis over 8 days of intracellular growth was evaluated in conjunction with one-step growth curves to correlate morphological differentiations with growth cycle phase. Lag phase occurred during the first 2 days postinfection (p.i.) and was primarily composed of SCV-to-LCV morphogenesis. LCV forms predominated over the next 4 days, during which exponential growth was observed. Calculated generation times during exponential phase were 10.2 h (by quantitative PCR assay) and 11.7 h (by replating fluorescent focus-forming unit assay). Stationary phase began at approximately 6 days p.i. and coincided with the reappearance of SCV, which increased in number at 8 days p.i. Quantitative reverse transcriptase-PCR demonstrated maximal expression of scvA, which encodes an SCV-specific protein, at 8 days p.i., while immunogold transmission electron microscopy revealed degradation of ScvA throughout lag and exponential phases, with increased expression observed at the onset of stationary phase. Collectively, these results indicate that the overall growth cycle of C. burnetii is characteristic of a closed bacterial system and that the replicative form of the organism is the LCV. The experimental model described in this report will allow a global transcriptome and proteome analysis of C. burnetii developmental forms.

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