Behavior of mitochondria during sporulation in yeast

1978 ◽  
Vol 36 (2) ◽  
pp. 406-407
Author(s):  
Barbara J. Stevens
Keyword(s):  
Cell Wall ◽  
Stationary Phase ◽  
Growth Phase ◽  
Serial Section ◽  
Logarithmic Phase ◽  
Serial Sections ◽  
Vegetative Cells ◽  
Thin Sections ◽  
Section Technique ◽  
Single Mitochondrion

The number and the form of mitochondria in vegetatively growing yeast, Saccharo-myces cerevisiae, have previously been determined by the use of serial thin sections of entire cells. It was found that the number of mitochondria is directly related to the growth phase: logarithmic phase cells contain few mitochondria, less than 10, while stationary phase cells have numerous organelles, from 30 to 50 individual mitochondria. A single mitochondrion was found in 2 log phase, glucose-repressed cells, but all other cells had more than one mitochondrion. In the present study, the behavior of the chondriome during meiosis and sporulation in yeast was followed by the serial section technique and was compared to that in vegetative cells.Diploid strains Z193, Z239-6B6B and s4l were obtained from R. and M. Esposito and S. Klapholz (Univ. of Chicago) and serial sections of strain 112 were kindly provided by D. Zickler (Univ. Paris-Sud). Cells were fixed in glutaraldehyde, treated with glusulase (Endo Lab.) or zymolyase (Kirin Brew. Co.) to remove the cell wall, and post-fixed in Dalton's chrome osmium.

Effects of pretreatments with sulfhydryls and alkylating agents on spheroplast formation from Schwanniomyces species

1984 ◽  
Vol 30 (3) ◽  
pp. 368-374 ◽  
Author(s):  
T. M. Dowhanick ◽  
C. J. Panchal ◽  
G. G. Stewart
Keyword(s):  
Cell Wall ◽  
Stationary Phase ◽  
Growth Phase ◽  
Cell Walls ◽  
Alkylating Agents ◽  
Inhibitory Effects ◽  
Late Stationary Phase ◽  
Stages Of Growth ◽  
Degradative Enzymes ◽  
Sulfhydryl Compounds

Pretreatment of cells with β-mercaptoethanol, dithiothreitol, or cysteine increased the rate of spheroplast formation at all stages of growth in Schwanniomyces castellii and S. occidentalis, but had little effect on final yields of spheroplasts when compared with controls. Pretreatment with iodoacetate and cystine resulted in decreased rates of formation and lower yields of spheroplasts at all stages of growth for both species. The enhanced rates of spheroplast formation in the presence of the sulfhydryl compounds were more pronounced when the experimental cells were derived from early or late stationary phase cultures, whereas the inhibitory effects of cystine and iodoacetate were not associated with the growth phase. In agreement with extant data on other yeast genera, sulfhydryl compounds increased the susceptibility of the yeast cell wall to degradative enzymes, whilst alkylating agents decreased susceptibility of cell walls to these enzymes.

scholarly journals The Nature of Antibacterial Adaptive Immune Responses against Staphylococcus aureus Is Dependent on the Growth Phase and Extracellular Peptidoglycan

2019 ◽  
Vol 88 (1) ◽  
Author(s):  
Payal P. Balraadjsing ◽  
Lisbeth D. Lund ◽  
Yuri Souwer ◽  
Sebastian A. J. Zaat ◽  
Hanne Frøkiær ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
T Cell ◽  
Stationary Phase ◽  
Growth Phase ◽  
Cell Response ◽  
Th17 Cell ◽  
Exponential Phase ◽  
Th1 Cell ◽  
Content Type

ABSTRACT Staphylococcus aureus has evolved different strategies to evade the immune response, which play an important role in its pathogenesis. The bacteria express and shed various cell wall components and toxins during different stages of growth that may affect the protective T cell responses to extracellular and intracellular S. aureus. However, if and how the dendritic cell (DC)-mediated T cell response against S. aureus changes during growth of the bacterium remain elusive. In this study, we show that exponential-phase (EP) S. aureus bacteria were endocytosed very efficiently by human DCs, and these DCs strongly promoted production of the T cell polarizing factor interleukin-12 (IL-12). In contrast, stationary-phase (SP) S. aureus bacteria were endocytosed less efficiently by DCs, and these DCs produced small amounts of IL-12. The high level of IL-12 production induced by EP S. aureus led to the development of a T helper 1 (Th1) cell response, which was inhibited after neutralization of IL-12. Furthermore, preincubation with the staphylococcal cell wall component peptidoglycan (PGN), characteristically shed during the exponential growth phase, modulated the DC response to EP S. aureus. PGN preincubation appeared to inhibit IL-12p35 expression, leading to downregulation of IL-12 and an increase of IL-23 production by DCs, enhancing Th17 cell development. Taken together, our data indicate that exponential-phase S. aureus bacteria induce a stronger IL-12-dependent Th1 cell response than stationary-phase S. aureus and that this Th1 cell response shifted toward a Th17 cell response in the presence of PGN.

scholarly journals Growth Phase-Coupled Alterations in Cell Structure and Function of Escherichia coli

2003 ◽  
Vol 185 (4) ◽  
pp. 1338-1345 ◽  
Author(s):  
Hideki Makinoshima ◽  
Shin-Ichi Aizawa ◽  
Hideo Hayashi ◽  
Takeyoshi Miki ◽  
Akiko Nishimura ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Stationary Phase ◽  
Cell Density ◽  
Growth Phase ◽  
Cell Structure ◽  
Volume Ratio ◽  
Density Increase ◽  
Electron Microscopic ◽  
Thin Sections ◽  
E Coli

ABSTRACT Escherichia coli cultures can be fractionated into more than 20 cell populations, each having a different bouyant density and apparently representing a specific stage of cell differentiation from exponential growth to stationary phase (H. Makinoshima, A. Nishimura, and A. Ishihama, Mol. Microbiol. 43:269-279, 2002). The density increase was found to be impaired at an early step for a mutant E. coli with the disrupted rpoS gene, which encodes the RNA polymerase RpoS (sigma-S) for stationary-phase gene transcription. This finding suggests that RpoS is need for the entire process of cell density increase. In the absence of RpoF sigma factor, the flagella are not formed as observed by electron microscopy, but the growth phase-coupled density increase takes place as in wild-type E. coli, confirming that the alteration in cell density is not directly correlated with the presence or absence of flagella. In the stationary-phase cells, accumulation of electron-dense areas was observed by electron microscopic observation of bacterial thin sections. By chemical determination, the increase in glycogen (or polysaccharides) was suggested to be one component, which contributes to the increase in weight-to-volume ratio of stationary-phase E. coli cells.

Effect of strain variation and growth phase of culture on dry weight and hexosamine content of cell wall layers of a marine pseudomonad

1977 ◽  
Vol 23 (4) ◽  
pp. 476-478
Author(s):  
Richard Sussman ◽  
Robert A. MacLeod
Keyword(s):  
Cell Wall ◽  
Stationary Phase ◽  
Dry Weight ◽  
Logarithmic Phase ◽  
Outer Cell ◽  
Space Layer ◽  
Strain Variation ◽  
Double Track ◽  
Hexosamine Content ◽  
Outer Cell Wall

Two variants of marine pseudomonad B-16 (ATCC 19855) differing in that one, variant 3, formed opaque colonies and the other, variant 7, formed translucent colonies were examined to determine if the variants differed in the amount and hexosamine content of their three outer cell wall layers. In both variants, the three outer layers of the cell wall, the loosely bound outer layer, the outer double-track layer, and the underlying (periplasmic space) layer contributed less to the dry weight of the cells when the cells were harvested in the stationary than in the logarithmic phase of growth. The hexosamine content of the layers of variant 3 increased dramatically as the cells went from the logarithmic to the stationary phase. The hexosamine content of the layers of variant 7 changed little by comparison. Thus cells of the variant which forms opaque colonies enrich the outer layers of their cell wall with hexosamine when grown to stationary phase.

Control of Enterotoxic Bacillus cereus on Poultry or Red Meats and in Beef Gravy by Gamma Irradiation

1994 ◽  
Vol 57 (9) ◽  
pp. 758-764 ◽  
Author(s):  
DONALD W. THAYER ◽  
GLENN BOYD
Keyword(s):  
Gamma Radiation ◽  
Stationary Phase ◽  
Bacillus Cereus ◽  
Radiation Resistance ◽  
Ground Beef ◽  
Logarithmic Phase ◽  
Vegetative Cells ◽  
Ground Pork ◽  
Pork Loin ◽  
Beef Round

The gamma-radiation resistance of five enterotoxic and one emetic isolate of Bacillus cereus vegetative cells and endospores was tested in mechanically deboned chicken meat (MDCM), ground turkey breast, ground beef round, ground pork loin and beef gravy. The D10 values for B. cereus ATCC 33018 were 0.184, 0.431 and 2.56 kGy for logarithmic-phase cells, stationary-phase cells, and endospores at 5°C on MDCM, respectively. Neither the presence nor absence of air during irradiation significantly affected radiation resistance of vegetative cells or endospores of B. cereus ATCC 33018 when present on MDCM. Irradiation temperature (−20 to +20°C) did affect the radiation resistance of stationary-phase vegetative cells and to a limited extent that of spores on MDCM. Impedance studies indicated that surviving vegetative cells were severely injured by radiation. A dose of 7.5 kGy at 5°C was required to eliminate a challenge of 4.6 × 103 B. cereus ATCC 33018 from temperature-abused MDCM (24 h at 30°C). The radiation resistance of a mixture of endospores of six strains to gamma radiation was 2.78 kGy in ground beef round, ground pork loin and beef gravy, but 1.91 kGy in turkey and MDCM. The results indicate that irradiation of meat or poultry can provide significant protection from vegetative cells but not from endospores of B. cereus.

GLYCOPEPTIDE SYNTHESIS DURING SPORULATION OF BACILLUS MEGATERIUM

1967 ◽  
Vol 13 (12) ◽  
pp. 1615-1620 ◽  
Author(s):  
William E. Gledhill
Keyword(s):  
Cell Wall ◽  
Stationary Phase ◽  
Bacillus Megaterium ◽  
Wall Material ◽  
Amino Sugars ◽  
Sporulation Medium ◽  
Cell Wall Material ◽  
Early Stationary Phase ◽  
Vegetative Cells ◽  
Number Of Cells

The present study was initiated to determine the amount of glycopeptide synthesized during sporulation of Bacillus megaterium. The glycopeptide fraction was isolated quantitatively from vegetative cells, sporulated cells, and free spores, and then assayed for amino sugars. The yields of glycopeptide hexosamine (GPH) in these preparations were compared on the basis of number of cells. During the early stationary phase of cultural growth, cells continued to synthesize cell wall material even though they did not divide or increase in size significantly. In the sporulation medium GPH synthesis was synchronized with the development of the endospore within the bacilli. During this period GPH formation occurred at an increased rate. Synthesis terminated as free spores were liberated from their sporangia. The total amount of GPH synthesized in the sporulating bacilli could be accounted for in the cleaned, free spores.

scholarly journals DNA-Binding Proteins Possibly Involved in Regulation of the Post-Logarithmic-Phase Expression of Lipoprotein P35 in Borrelia burgdorferi

2000 ◽  
Vol 182 (2) ◽  
pp. 522-525 ◽  
Author(s):  
Karl J. Indest ◽  
Mario T. Philipp
Keyword(s):  
Dna Binding ◽  
Borrelia Burgdorferi ◽  
Stationary Phase ◽  
Growth Phase ◽  
Promoter Region ◽  
Protein Complexes ◽  
Phase Cell ◽  
Logarithmic Phase ◽  
Specific Complex

ABSTRACT Previously, we have shown that the transcription ofp35, a lipoprotein gene of Borrelia burgdorferi, is upregulated or initiated during the post-logarithmic bacterial growth phase in vitro. To identify potential regulatory factors, we examined the formation of DNA-protein complexes by electromobility shift assay, using a 157-bp DNA fragment that spans the p35 promoter region and cell-free extracts of spirochetes harvested from both logarithmic and stationary growth phases. The binding properties of the extracts with the promoter region of the flaB gene, a constitutively expressed, growth-phase-independent gene, were also compared. The results from these experiments demonstrate that B. burgdorferistationary-phase cell-free extracts have a growth-phase-dependent DNA binding protein that interacts specifically with the p35promoter region. We show, in addition, that a segment from the 157-bpp35 promoter region which contains both a T-rich stretch and an inverted repeat is able to compete off the stationary-phase-specific complex when the segment is present in molar excess.

scholarly journals Is the cellular and molecular machinery docile in the stationary phase of Escherichia coli?

2015 ◽  
Vol 43 (2) ◽  
pp. 168-171 ◽  
Author(s):  
Parul Mehta ◽  
Goran Jovanovic ◽  
Liming Ying ◽  
Martin Buck
Keyword(s):  
Stationary Phase ◽  
Single Molecule ◽  
Growth Phase ◽  
Bound States ◽  
Cell Envelope ◽  
Stationary Phases ◽  
Negative Regulator ◽  
Logarithmic Phase ◽  
Bacterial Cells ◽  
Highly Active

The bacterial cell envelope retains a highly dense cytoplasm. The properties of the cytoplasm change with the metabolic state of the cell, the logarithmic phase (log) being highly active and the stationary phase metabolically much slower. Under the differing growth phases, many different types of stress mechanisms are activated in order to maintain cellular integrity. One such response in enterobacteria is the phage shock protein (Psp) response that enables adaptation to the inner membrane (IM) stress. The Psp system consists of a transcriptional activator PspF, negative regulator PspA, signal sensors PspBC, with PspA and PspG acting as effectors. The single molecule imaging of the PspF showed the existence of dynamic communication between the nucleoid-bound states of PspF and membrane via negative regulator PspA and PspBC sensors. The movement of proteins in the cytoplasm of bacterial cells is often by passive diffusion. It is plausible that the dynamics of the biomolecules differs with the state of the cytoplasm depending on the growth phase. Therefore, the Psp response proteins might encounter the densely packed glass-like properties of the cytoplasm in the stationary phase, which can influence their cellular dynamics and function. By comparing the properties of the log and stationary phases, we find that the dynamics of PspF are influenced by the growth phase and may be controlled by the changes in the cytoplasmic fluidity.

Morphological Characterization of Mycobacteriophage R1

1974 ◽  
Vol 32 ◽  
pp. 254-255
Author(s):  
B. L. Soloff ◽  
T. A. Rado
Keyword(s):  
Carbon Source ◽  
Stationary Phase ◽  
Growth Phase ◽  
Minimal Medium ◽  
Morphological Characterization ◽  
Logarithmic Growth Phase ◽  
Complete Lysis ◽  
Lysogenic Culture ◽  
Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

Three-Dimensional Reconstruction Using Stereo Pairs from Serial Thick Sections

1977 ◽  
Vol 35 ◽  
pp. 562-563
Author(s):  
Robert Glaeser ◽  
Thomas Bauer ◽  
David Grano
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
Serial Sections ◽  
Thin Sections ◽  
3 Dimensional ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Dimensional Reconstruction ◽  
Stereo Imagery ◽  
Whole Mounts

In transmission electron microscopy, the 3-dimensional structure of an object is usually obtained in one of two ways. For objects which can be included in one specimen, as for example with elements included in freeze- dried whole mounts and examined with a high voltage microscope, stereo pairs can be obtained which exhibit the 3-D structure of the element. For objects which can not be included in one specimen, the 3-D shape is obtained by reconstruction from serial sections. However, without stereo imagery, only detail which remains constant within the thickness of the section can be used in the reconstruction; consequently, the choice is between a low resolution reconstruction using a few thick sections and a better resolution reconstruction using many thin sections, generally a tedious chore. This paper describes an approach to 3-D reconstruction which uses stereo images of serial thick sections to reconstruct an object including detail which changes within the depth of an individual thick section.

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