scholarly journals STUDIES ON THE MODE OF SPREAD OF B. ENTERITIDIS MOUSE TYPHOID INFECTION

1927 ◽  
Vol 46 (6) ◽  
pp. 871-886 ◽  
Author(s):  
Leslie T. Webster ◽  
Caspar Burn
Keyword(s):  
Growth Rate ◽  
Single Cell ◽  
Cell Cultures ◽  
Bacterial Cell ◽  
Single Cells ◽  
Oxygen Absorption ◽  
Acid Solutions ◽  
Staining Property ◽  
Low Degree ◽  
Cell Changes

1. During early stages of multiplication, single cells from smooth-, mucoid-, and rough-susceptible and variant colonies show no differences in morphology or growth rate. 2. Cells from 18 to 24 hour single cell cultures of these various colony types possess similar oxygen absorption and cataphoretic migratory rates. In staining property, the cells from mucoid colonies appear larger, and those from rough colonies smaller, than the typical cells from smooth-susceptible colonies. 3. Cells from bacteriophage-resistant colonies differ from those of bacteriophage-susceptible colonies in their ability to multiply luxuriantly in the presence of bacteriophage, and in their tendency to flocculate in acid solutions at pH 3.8 to 4.1, as well as in their low degree of virulence. 4. Cells from smooth bacteriophage-susceptible colonies in contact with bacteriophage under conditions where multiplication is restrained may be altered so as to resemble the cells from the bacteriophage-resistant colonies. 5. These facts furnish evidence that bacteriophage adheres to the surface of the bacterial cell and that the various cell changes and colony alterations are of an environmental rather than genetic nature.

scholarly journals Colony formation of clone-sorted human hematopoietic progenitors

Blood ◽  
1990 ◽  
Vol 75 (10) ◽  
pp. 1941-1946 ◽  
Author(s):  
H Ema ◽  
T Suda ◽  
Y Miura ◽  
H Nakauchi
Keyword(s):  
Single Cell ◽  
Cell Cultures ◽  
Mononuclear Cells ◽  
Direct Action ◽  
Single Cells ◽  
Accurate Estimation ◽  
Hematopoietic Progenitors ◽  
Gm Csf ◽  
Cd34 Cells ◽  
Sorting System

Abstract To characterize human hematopoietic progenitors, we performed methylcellulose cultures of single cells isolated from a population of CD34+ cells by fluorescence-activated cell-sorting (FACS) clone-sorting system. CD34+ cells were detected in bone marrow (BM) and peripheral blood (PB) cells at incidences of 1.0% and 0.01% of total mononuclear cells, respectively. Single cell cultures revealed that approximately 37% of BM CD34+ cells formed colonies in the presence of phytohemagglutinin-leukocyte conditioned medium and erythropoietin. Erythroid bursts-, granulocyte-macrophage (GM) colony-, and pure macrophage (Mac) colony-forming cells were 10% each in CD34+ cells. Approximately 15% of PB CD34+ cells formed colonies in which erythroid bursts were predominant. CD34+ cells were heterogeneous and fractionated by several antibodies in FACS multicolor analysis. In these fractionated cells, CD34+, CD33+ cells formed GM and Mac colonies 7 to 10 times as often as CD34+, CD33- cells. Most of the erythroid bursts and colonies were observed in the fraction of CD34+, CD13- cells or CD34+, CD33- cells. The expression of HLA-DR on CD34+ cells was not related to the incidence, size, or type of colonies. There was no difference in the phenotypical heterogeneity of CD34+ cells between BM and PB. About 10% of CD34+ cells were able to form G colonies in response to granulocyte colony-stimulating factor (G-CSF) and to form Mac colonies in GM-CSF or interleukin-3 (IL-3). Progenitors capable of generating colonies by stimulation of G-CSF were more enriched in CD34+, CD33+ fraction than in CD34+, CD33- fraction. Thus, single cell cultures using the FACS clone-sorting system provide an accurate estimation of hematopoietic progenitors and an assay system for direct action of colony-stimulating factors.

scholarly journals Noise-driven growth rate gain in clonal cellular populations

2016 ◽  
Vol 113 (12) ◽  
pp. 3251-3256 ◽  
Author(s):  
Mikihiro Hashimoto ◽  
Takashi Nozoe ◽  
Hidenori Nakaoka ◽  
Reiko Okura ◽  
Sayo Akiyoshi ◽  
...  
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Single Cell ◽  
Single Cells ◽  
Population Level ◽  
Growth Conditions ◽  
Cell Dynamics ◽  
Generation Times ◽  
Complex Population ◽  
The Mean

Cellular populations in both nature and the laboratory are composed of phenotypically heterogeneous individuals that compete with each other resulting in complex population dynamics. Predicting population growth characteristics based on knowledge of heterogeneous single-cell dynamics remains challenging. By observing groups of cells for hundreds of generations at single-cell resolution, we reveal that growth noise causes clonal populations of Escherichia coli to double faster than the mean doubling time of their constituent single cells across a broad set of balanced-growth conditions. We show that the population-level growth rate gain as well as age structures of populations and of cell lineages in competition are predictable. Furthermore, we theoretically reveal that the growth rate gain can be linked with the relative entropy of lineage generation time distributions. Unexpectedly, we find an empirical linear relation between the means and the variances of generation times across conditions, which provides a general constraint on maximal growth rates. Together, these results demonstrate a fundamental benefit of noise for population growth, and identify a growth law that sets a “speed limit” for proliferation.

scholarly journals dMSCC: A microfluidic platform for microbial single-cell cultivation under dynamic environmental medium conditions

2020 ◽  
Author(s):  
Sarah Täuber ◽  
Corinna Golze ◽  
Phuong Ho ◽  
Eric von Lieres ◽  
Alexander Grünberger
Keyword(s):  
Growth Rate ◽  
Single Cell ◽  
Environmental Conditions ◽  
Cellular Response ◽  
Large Scale ◽  
Single Cells ◽  
Model Organism ◽  
Colony Growth ◽  
Cell Cultivation ◽  
Natural Habitats

AbstractIn nature and in technical systems, microbial cells are often exposed to rapidly fluctuating environmental conditions. These conditions can vary in quality, e.g., existence of a starvation zone, and quantity, e.g., average residence time in this zone. For strain development and process design, cellular response to such fluctuations needs to be systematically analysed. However, the existing methods for physically emulating rapidly changing environmental conditions are limited in spatio-temporal resolution. Hence, we present a novel microfluidic system for cultivation of single cells and small cell clusters under dynamic environmental conditions (dynamic microfluidic single-cell cultivation (dMSCC)). This system enables to control nutrient availability and composition between two media with second to minute resolution. We validate our technology using the industrially relevant model organism Corynebacterium glutamicum. The organism was exposed to different oscillation frequencies between nutrient excess (feasts) and scarcity (famine). Resulting changes in cellular physiology, such as the colony growth rate and cell morphology were analysed and revealed significant differences with growth rate and cell length between the different conditions. dMSCC also allows to apply defined but randomly changing nutrient conditions, which is important for reproducing more complex conditions from natural habitats and large-scale bioreactors. The presented system lays the foundation for the cultivation of cells under complex changing environmental conditions.

scholarly journals Basal and thyroliberin-stimulated prolactin synthesis in single-cell cultures and in populations of rat pituitary cells

1976 ◽  
Vol 158 (1) ◽  
pp. 119-125 ◽  
Author(s):  
K M Gautvik ◽  
S Fossum
Keyword(s):  
Single Cell ◽  
Cell Cultures ◽  
Single Cells ◽  
Sodium Dodecyl ◽  
Prolactin Secretion ◽  
Pituitary Cells ◽  
Hormone Synthesis ◽  
Specific Fluorescence ◽  
Rat Pituitary ◽  
Prolactin Synthesis

1. Newly synthesized prolactin was obtained from cultures of rat pituitary tumour cells (GH4C1 cells) after incubation with [35S]methionine. 2. Radioactive synthesized and secreted prolactin was quantified by an immunoprecipitation method by using disc-gel electrophoresis of the dissolved immunoprecipitate in the presence of sodium dodecyl sulphate. By using a microanalytical modification, hormone synthesis and secretion could also be studied in single-cell cultures. This technique was combined with a cytoimmunofluorescence method in which rhodamine-conjugated antibodies were used for studying intracellular prolactin. 3. The presence of radioactive synthesized and secreted prolactin was demonstrated in nine out of 13 single-cell cultures. Cell cultures containing 10 cells or more and clonal populations originating from one cell always secreted radioactive prolactin. 4. Thyroliberin treatment (2 muM) for 24h increased the extracellular accumulation of radioactive prolactin in five out of seven single-cell cultures and always in populations of cells. 5. The number of cells showing prolactin specific fluorescence increased from 20 to 50% and the intensity of this fluorescence became greater after thyroliberin treatment. 6. Studies of [35S]prolactin secretion from single cells and immunochemical detection of intracellular prolactin showed that some cells in an unsynchronized population did not secret radioactive prolactin or show prolactin specific fluorescence. 7. The quantitative effect of thyroliberin as studied in single-cell cultures suggested that the main if not the only effect was to increase prolactin synthesis in cells already producing hormone.

scholarly journals Osmolyte homeostasis controls single-cell growth rate and maximum cell size of Saccharomyces cerevisiae

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Tom Altenburg ◽  
Björn Goldenbogen ◽  
Jannis Uhlendorf ◽  
Edda Klipp
Keyword(s):  
Growth Rate ◽  
Cell Wall ◽  
Cell Growth ◽  
Single Cell ◽  
Cell Size ◽  
Single Cells ◽  
Turgor Pressure ◽  
Thermodynamic Quantities ◽  
Cell Growth Rate ◽  
Final Size

Abstract Cell growth is well described at the population level, but precisely how nutrient and water uptake and cell wall expansion drive the growth of single cells is poorly understood. Supported by measurements of single-cell growth trajectories and cell wall elasticity, we present a single-cell growth model for yeast. The model links the thermodynamic quantities, such as turgor pressure, osmolarity, cell wall elasto-plasticity, and cell size, applying concepts from rheology and thin shell theory. It reproduces cell size dynamics during single-cell growth, budding, and hyper-osmotic or hypo-osmotic stress. We find that single-cell growth rate and final size are primarily governed by osmolyte uptake and consumption, while bud expansion requires additionally different cell wall extensibilities between mother and bud. Based on first principles the model provides a more accurate description of size dynamics than previous attempts and its analytical simplification allows for easy combination with models for other cell processes.

A study of changes in flocculence in a single cell culture of a strain of Saccharomyces cerevisiae

1963 ◽  
Vol 157 (967) ◽  
pp. 223-233 ◽  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Culture ◽  
Liquid Medium ◽  
Single Cell ◽  
Cell Cultures ◽  
Single Cells ◽  
Selective Advantage ◽  
Brewing Yeast ◽  
Flocculent Yeast ◽  
Single Cell Culture

A culture from a single cell of a flocculent brewing yeast became less flocculent during sub-culture on agar slopes. It was found that the culture had become a mixture of a number of variants differing in degree of flocculence. Five of the variants were studied using a sedi­-mentation method to measure flocculence. During subculture on agar and in liquid medium, single cell cultures of all these variants except the least flocculent gave rise to other variants. The proportion of less flocculent yeast increased during further subculture. The change was faster in liquid medium than on agar slopes. Yeast with more stable flocculence could be selected from the part of the population which did not change. Experiments with mixtures of ‘stable’ yeast indicated that the less flocculent yeast had a selective advantage, and that the mechanism of the selection involves the different physical properties of the yeast. All variants examined had the same rate of growth. Cultures derived from single cells of a given variant tended to give rise to the same new variants. Yeast with flocculence similar to the original strains could be isolated from the variant strains. It was not possible to determine whether these variants were produced by gene mutation since spore formation has never been detected in this yeast.

scholarly journals Osmolyte homeostasis controls single-cell growth rate and maximum cell size ofSaccharomyces cerevisiae

2019 ◽  
Author(s):  
Tom Altenburg ◽  
Björn Goldenbogen ◽  
Jannis Uhlendorf ◽  
Edda Klipp
Keyword(s):  
Growth Rate ◽  
Cell Wall ◽  
Cell Growth ◽  
Single Cell ◽  
Cell Size ◽  
Single Cells ◽  
Turgor Pressure ◽  
Thermodynamic Quantities ◽  
Cell Growth Rate ◽  
Final Size

Cell growth is well described at the population level, but precisely how nutrient and water uptake and cell wall expansion drive the growth of single cells is poorly understood. Supported by measurements of single-cell growth trajectories and cell wall elasticity, we present a single-cell growth model for yeast. The model links the thermodynamic quantities turgor pressure, osmolarity, cell wall elasto-plasticity, and cell size, using concepts from rheology and thin shell theory. It reproduces cell size dynamics during single-cell growth, budding, and hyper- or hypoosmotic stress. We find that single-cell growth rate and final size are primarily governed by osmolyte uptake and consumption, while bud expansion depends additionally on different cell wall extensibilities of mother and bud. Based on first principles the model provides a more accurate description of size dynamics than previous attempts and its analytical simplification allows for easy combination with models for other cell processes.

scholarly journals Insights on the Control of Yeast Single-Cell Growth Variability by Members of the Trehalose Phosphate Synthase (TPS) Complex

2021 ◽  
Vol 9 ◽  
Author(s):  
Sevan Arabaciyan ◽  
Michael Saint-Antoine ◽  
Cathy Maugis-Rabusseau ◽  
Jean-Marie François ◽  
Abhyudai Singh ◽  
...  
Keyword(s):  
Growth Rate ◽  
Cell Growth ◽  
Single Cell ◽  
Single Cells ◽  
Expression Level ◽  
Individual Growth ◽  
Single Cell Level ◽  
Cell Level ◽  
Growth Variability ◽  
Phosphate Synthase

Single-cell variability of growth is a biological phenomenon that has attracted growing interest in recent years. Important progress has been made in the knowledge of the origin of cell-to-cell heterogeneity of growth, especially in microbial cells. To better understand the origins of such heterogeneity at the single-cell level, we developed a new methodological pipeline that coupled cytometry-based cell sorting with automatized microscopy and image analysis to score the growth rate of thousands of single cells. This allowed investigating the influence of the initial amount of proteins of interest on the subsequent growth of the microcolony. As a preliminary step to validate this experimental setup, we referred to previous findings in yeast where the expression level of Tsl1, a member of the Trehalose Phosphate Synthase (TPS) complex, negatively correlated with cell division rate. We unfortunately could not find any influence of the initial TSL1 expression level on the growth rate of the microcolonies. We also analyzed the effect of the natural variations of trehalose-6-phosphate synthase (TPS1) expression on cell-to-cell growth heterogeneity, but we did not find any correlation. However, due to the already known altered growth of the tps1Δ mutants, we tested this strain at the single-cell level on a permissive carbon source. This mutant showed an outstanding lack of reproducibility of growth rate distributions as compared to the wild-type strain, with variable proportions of non-growing cells between cultivations and more heterogeneous microcolonies in terms of individual growth rates. Interestingly, this variable behavior at the single-cell level was reminiscent to the high variability that is also stochastically suffered at the population level when cultivating this tps1Δ strain, even when using controlled bioreactors.

scholarly journals Single Cell Observations Show Persister Cells Wake Based on Ribosome Content

2018 ◽  
Author(s):  
Jun-Seob Kim ◽  
Thomas K. Wood
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Cell Division ◽  
Single Cell ◽  
Single Cells ◽  
Persister Cells ◽  
Division Iii ◽  
Bona Fide ◽  
Persister Cell ◽  
Low Levels

ABSTRACTSince persister cells survive antibiotic treatments through dormancy and resuscitate to reconstitute infections, it is imperative to determine the rate at which these cells revive. Using two sets ofEscherichia colipersister cells, those arising naturally at low levels and those generated at high levels by ceasing transcription via rifampicin pretreatment (shown to be bona fide persisters through seven sets of experiments), we used microscopy of single cells to determine that persisters have low levels of antibiotic-corrupting proteins and that their resuscitation is heterogeneous and includes cells that grow immediately. In all, five phenotypes were found for persister cell resuscitation: (i) immediate division, (ii) immediate elongation followed by division, (iii) immediate elongation but no division, (iv) delayed elongation/division, and (v) no growth. In addition, once cell division begins, the growth rate is that of exponential cells. Critically, the greater the ribosome content, the faster the persister cells resuscitate.

scholarly journals Cell biological studies of ethanologenic bacterium Zymomonas mobilis

2020 ◽  
Author(s):  
Katsuya Fuchino ◽  
Helena Chan ◽  
Ling Chin Hwang ◽  
Per Bruheim
Keyword(s):  
Cell Growth ◽  
Single Cell ◽  
Cell Size ◽  
Bacterial Cell ◽  
Zymomonas Mobilis ◽  
Single Cells ◽  
Biofuel Production ◽  
Public Attention ◽  
Biological Studies ◽  
Cell Organization

AbstractAlphaproteobacterium Zymomonas mobilis exhibits extreme ethanologenic physiology, making this species a promising biofuel producer. Numerous studies have investigated its biology relevant to industrial applications and mostly at the population level. However, the organization of single cells in this industrially important, polyploid species has been largely uncharacterized.In the present study, we characterized basic cellular behaviour of Z. mobilis strain Zm6 at a single cell level. We observed that growing Z. mobilis cells often divided at non mid-cell position, which contributed to variant cell size at birth. Yet, the cell size variance was regulated by a modulation of cell cycle span, mediated by a correlation of bacterial tubulin homologue FtsZ-ring accumulation with cell growth. The Z. mobilis culture also exhibited heterogeneous cellular DNA contents among individual cells, which might have been caused by asynchronous replication of chromosome that was not coordinated to cell growth. Furthermore, slightly angled divisions might have rendered temporary curvatures of attached Z. mobilis cells. Overall, the presented study uncovered a novel bacterial cell organization in Z. mobilis, the metabolism of which is not favoured for biosynthesis to build biomass.ImportanceWith increasing environmental concerns about the exhausting use of fossil fuels, a development of sustainable biofuel production platform has been attracting significant public attention. Ethanologenic Z. mobilis species are endowed with an efficient ethanol-fermentation capacity that surpass, in several aspects, that of the baker’s yeast Saccharomyces cerevisiae, the most used microorganism for ethanol productions. For a development of Z. mobilis culture-based biorefinery, an investigation of its uncharacterized cell biology is important, because bacterial cellular organization and metabolism are closely associated with each other in a single cell compartment.In addition, the current work highlights that polyploid bacterium Z. mobilis exhibits a distinctive mode of bacterial cell organization, reflecting its unique metabolism that do not prioritize incorporation of nutrients to cell growth. Thus, another significance of presented work is to advance our general understanding in the diversity of bacterial cell architecture.

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