Changes in patterns of respiration and glucose utilisation in Candida utilis during the cell cycle: some variations with growth rate

1975 ◽  
Vol 21 (7) ◽  
pp. 1013-1019 ◽  
Author(s):  
P. S. S. Dawson ◽  
D. W. S. Westlake
Keyword(s):  
Cell Cycle ◽  
Growth Rate ◽  
Oxygen Uptake ◽  
Candida Utilis ◽  
Hexose Monophosphate ◽  
Mineral Salts ◽  
Glucose Utilisation ◽  
Growth Metabolism ◽  
Doubling Times

The release of 14CO2 from 14C-labelled glucose (G-1-14C, G-3,4-14C, G-6-14C) was followed in phased cultures of Candida utilis grown in a glucose – mineral salts medium under altered conditions of carbon:nitrogen limitation at doubling times of 2, 4, and 6 h. Changes in oxygen uptake and CO2 evolution were observed and respirometric studies showed that the relative contributions of the Embden-Meyerhof-Parnas and hexose monophosphate pathways varied over the cell cycle and changed with growth rate. The results are discussed in relation to the growth metabolism of the cells.

Some comparative observations on the relative contributions of alternate pathways in the metabolism of glucose by Candida utilis

1976 ◽  
Vol 22 (7) ◽  
pp. 996-1001 ◽  
Author(s):  
P. S. S. Dawson ◽  
W. Okada ◽  
L. P. Steinhauer
Keyword(s):  
Cell Cycle ◽  
Growth Rate ◽  
Nutrient Limitation ◽  
Cell Population ◽  
Candida Utilis ◽  
Mineral Salts ◽  
Growth Sequence ◽  
Cultivation Techniques ◽  
Unit Performance

Candida utilis was grown in batch, chemostat, and continuously synchronised (phased) culture on a nitrogen-limited glucose mineral salts medium: phosphorus- and carbon-limited phased cultures were also used. The 14CO2 evolved from [G-1-14C] and [G-6-14C] was used, as a simple C1/C6 ratio, to observe the relative changes in EMP and HMP contributions during growth of the cultures. The ratio varied during the cell cycle, and changed with growth rate, and with nutrient limitation. The changes generally indicated that the HMP predominated, most notably in the early part of the batch-growth sequence and early in the cell cycle.The overall results reflected the relative merits of the different cultivation techniques for examining microbial metabolism: the advantage of a greater resolution by the synchronised method, based upon the unit performance rather than the randomised mean performance of the cell population, was demonstrated.

The oxygen uptake of phased yeast cultures growing at different doubling times on nitrogen- and energy-limited media

1968 ◽  
Vol 14 (10) ◽  
pp. 1127-1131 ◽  
Author(s):  
J. Müller ◽  
P. S. S. Dawson
Keyword(s):  
Energy Source ◽  
Cell Cycle ◽  
Oxygen Uptake ◽  
Doubling Time ◽  
Candida Utilis ◽  
Limited Growth ◽  
Yeast Cultures ◽  
Limiting Nutrient ◽  
Source Limitation ◽  
Doubling Times

The oxygen uptake of Candida utilis growing in phased culture at doubling times of 4, 6, 8, and 12 hours was measured under conditions of nitrogen and energy source limitation. No abrupt doubling of oxygen uptake was observed at any stage of the cell cycle. The pattern of oxygen uptake was closely related to the assimilation of the growth-limiting nutrient. In nitrogen-limited growth, the specific oxygen uptake (Qo2) was found to decrease as the doubling time increased, but, in glucose-limited growth, no change was observed.

Growth, cell cultivation, cell metabolism, and the cell cycle of Candida utilis as explored by continuous phased culture

1985 ◽  
Vol 31 (3) ◽  
pp. 183-189 ◽  
Author(s):  
P. S. S. Dawson
Keyword(s):  
Cell Cycle ◽  
Growth Rate ◽  
Doubling Time ◽  
Microbial Growth ◽  
Candida Utilis ◽  
Cell Metabolism ◽  
Growth Theory ◽  
Cell Cultivation ◽  
Phenotypic Changes ◽  
Nitrogen Phosphorus

The problem of microbial growth, centred both on the population and the cell, and studied largely in batch culture, is also accessible by open methods of continuous culture which release such growth studies from restrictions imposed by the traditional methods. Thus, continuous phased (synchrony) culture enables studies of the cell cycle to be conducted systematically under different conditions of nutrient limitation and growth rate, and allows the phenotypic changes of chemostat steady states to be expressed as patterns of "cell cycle" behaviour over the doubling time. Studies conducted with Candida utilis in this way, in carbon-, nitrogen-, phosphorus-, and other nutrient-limited growths, have revealed a variable behaviour in the cell cycle, especially in the G1 period. Such variability in cell cycle behaviour is closely linked to the nutrient control of growth in the culture and generally accords with the Monod growth theory. Such variable behaviours for the cell are examined and assessed in relation to leading contemporary models for the cell cycle.

scholarly journals A general quantitative relation linking bacterial cell growth and the cell cycle

2019 ◽  
Author(s):  
Hai Zheng ◽  
Yang Bai ◽  
Meiling Jiang ◽  
Taku A. Tokuyasu ◽  
Xiongliang Huang ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Growth Rate ◽  
Cell Division ◽  
Bacterial Cell ◽  
Cell Mass ◽  
Quantitative Relation ◽  
Growth Physiology ◽  
Dividing Cells ◽  
Bacterial Cell Cycle ◽  
Doubling Times

The foundation of bacterial cell cycle studies has long resided in two interconnected dogmas between biomass growth, DNA replication, and cell division during exponential growth: the SMK growth law that relates cell mass (a measure of cell size) to growth rate1, and Donachie’s hypothesis of a growth-rate-independent initiation mass2. These dogmas have spurred many efforts to understand their molecular bases and physiological consequences3–12. Most of these studies focused on fast-growing cells, with doubling times shorter than 60 min. Here, we systematically studied the cell cycle of E. coli for a broad range of doubling times (24 min to over 10 hr), with particular attention on steady-state growth. Surprisingly, we observed that neither dogma held across the range of growth rates examined. In their stead, a new linear relation unifying the slow- and fast-growth regimes was revealed between the cell mass and the number of cell divisions it takes to replicate and segregate a newly initiated pair of replication origins. This and other findings in this study suggest a single-cell division model, which not only reproduces the bulk relations observed but also recapitulates the adder phenomenon established recently for stochastically dividing cells13–15. These results allowed us to develop quantitative insight into the bacterial cell cycle, providing a firm new foundation for the study of bacterial growth physiology.

CONTINUOUS PHASED GROWTH, WITH A MODIFIED CHEMOSTAT

1965 ◽  
Vol 11 (6) ◽  
pp. 893-903 ◽  
Author(s):  
P. S. S. Dawson
Keyword(s):  
Cell Cycle ◽  
Growth Rate ◽  
Amino Acid ◽  
Candida Utilis ◽  
Chemostat Culture ◽  
Amino Acid Pool ◽  
Acid Pool ◽  
Preliminary Results

A modified chemostat is described which may be used to maintain a continuously phased population in the culture for periods of many months. Preliminary results with Candida utilis show that changes in the amino acid pool occur over the cell cycle, and that these changes alter with growth rate. The significance of the method and its relationship to chemostat culture are outlined.

scholarly journals The Consequences of Budding versus Binary Fission on Adaptation and Aging in Primitive Multicellularity

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 661
Author(s):  
Hanna Isaksson ◽  
Peter L. Conlin ◽  
Ben Kerr ◽  
William C. Ratcliff ◽  
Eric Libby
Keyword(s):  
Cell Cycle ◽  
Growth Rate ◽  
Cellular Senescence ◽  
Carrying Capacity ◽  
The Other ◽  
Binary Fission ◽  
Fundamental Aspect ◽  
Accumulated Damage ◽  
Cell Age ◽  
Multicellular Organisms

Early multicellular organisms must gain adaptations to outcompete their unicellular ancestors, as well as other multicellular lineages. The tempo and mode of multicellular adaptation is influenced by many factors including the traits of individual cells. We consider how a fundamental aspect of cells, whether they reproduce via binary fission or budding, can affect the rate of adaptation in primitive multicellularity. We use mathematical models to study the spread of beneficial, growth rate mutations in unicellular populations and populations of multicellular filaments reproducing via binary fission or budding. Comparing populations once they reach carrying capacity, we find that the spread of mutations in multicellular budding populations is qualitatively distinct from the other populations and in general slower. Since budding and binary fission distribute age-accumulated damage differently, we consider the effects of cellular senescence. When growth rate decreases with cell age, we find that beneficial mutations can spread significantly faster in a multicellular budding population than its corresponding unicellular population or a population reproducing via binary fission. Our results demonstrate that basic aspects of the cell cycle can give rise to different rates of adaptation in multicellular organisms.

scholarly journals The Constitutive Centromere Component CENP-50 Is Required for Recovery from Spindle Damage

2005 ◽  
Vol 25 (23) ◽  
pp. 10315-10328 ◽  
Author(s):  
Yukinori Minoshima ◽  
Tetsuya Hori ◽  
Masahiro Okada ◽  
Hiroshi Kimura ◽  
Tokuko Haraguchi ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Growth Rate ◽  
Mitotic Checkpoint ◽  
Loss Of Function ◽  
Wild Type ◽  
Centromere Function ◽  
Dt40 Cells ◽  
Precise Role ◽  
Chicken Dt40 Cell

ABSTRACT We identified CENP-50 as a novel kinetochore component. We found that CENP-50 is a constitutive component of the centromere that colocalizes with CENP-A and CENP-H throughout the cell cycle in vertebrate cells. To determine the precise role of CENP-50, we examined its role in centromere function by generating a loss-of-function mutant in the chicken DT40 cell line. The CENP-50 knockout was not lethal; however, the growth rate of cells with this mutation was slower than that of wild-type cells. We observed that the time for CENP-50-deficient cells to complete mitosis was longer than that for wild-type cells. Centromeric localization of CENP-50 was abolished in both CENP-H- and CENP-I-deficient cells. Coimmunoprecipitation experiments revealed that CENP-50 interacted with the CENP-H/CENP-I complex in chicken DT40 cells. We also observed severe mitotic defects in CENP-50-deficient cells with apparent premature sister chromatid separation when the mitotic checkpoint was activated, indicating that CENP-50 is required for recovery from spindle damage.

Evaluation of genomic sequence-based growth rate methods for synchronized Synechococcus cultures

2021 ◽  
Author(s):  
Julia Carroll ◽  
Nicolas Van Oostende ◽  
Bess B. Ward
Keyword(s):  
Cell Cycle ◽  
Growth Rate ◽  
Dna Replication ◽  
Growth Rates ◽  
Genomic Sequence ◽  
Niche Differentiation ◽  
Trophic Levels ◽  
Individual Species ◽  
Cell Counts

Standard methods for calculating microbial growth rates (μ) through the use of proxies, such as in situ fluorescence, cell cycle, or cell counts, are critical for determining the magnitude of the role bacteria play in marine carbon (C) and nitrogen (N) cycles. Taxon-specific growth rates in mixed assemblages would be useful for attributing biogeochemical processes to individual species and understanding niche differentiation among related clades, such as found in Synechococcus and Prochlorococcus . We tested three novel DNA sequencing-based methods (iRep, bPTR, and GRiD) for evaluating growth of light synchronized Synechococcus cultures under different light intensities and temperatures. In vivo fluorescence and cell cycle analysis were used to obtain standard estimates of growth rate for comparison with the sequence-based methods (SBM). None of the SBM values were correlated with growth rates calculated by standard techniques despite the fact that all three SBM were correlated with percentage of cells in S phase (DNA replication) over the diel cycle. Inaccuracy in determining the time of maximum DNA replication is unlikely to account entirely for the absence of relationship between SBM and growth rate, but the fact that most microbes in the surface ocean exhibit some degree of diel cyclicity is a caution for application of these methods. SBM correlate with DNA replication but cannot be interpreted quantitatively in terms of growth rate. Importance Small but abundant, cyanobacterial strains such as the photosynthetic Synechococcus spp. are essential because they contribute significantly to primary productivity in the ocean. These bacteria generate oxygen and provide biologically-available carbon, which is essential for organisms at higher trophic levels. The small size and diversity of natural microbial assemblages means that taxon-specific activities (e.g., growth rate) are difficult to obtain in the field. It has been suggested that sequence-based methods (SBM) may be able to solve this problem. We find, however, that SBM can detect DNA replication and are correlated with phases of the cell cycle but cannot be interpreted in terms of absolute growth rate for Synechococcus cultures growing under a day-night cycle, like that experienced in the ocean.

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