scholarly journals THE FATE OF MITOCHONDRIA DURING AGING IN TETRAHYMENA PYRIFORMIS

1964 ◽  
Vol 20 (1) ◽  
pp. 113-129 ◽  
Author(s):  
Alfred M. Elliott ◽  
Il Jin Bak
Keyword(s):  
Growth Phase ◽  
Tetrahymena Pyriformis ◽  
Growth Cycle ◽  
Stationary Growth Phase ◽  
Stationary Growth ◽  
Logarithmic Growth Phase ◽  
Cytoplasmic Structures ◽  
Hydrolysis Of ◽  
Logarithmic Growth ◽  
Single Mitochondrion

During the growth cycle of Tetrahymena pyriformis the mitochondria undergo changes in position, number, and structure. Ciliates in the logarithmic growth phase possess elongated mitochondria which are aligned along the plasma membrane and are closely associated with the kinetosomes and kinetodesmata. Mitochondria appear to divide across the long axis at this time, resulting in two or more products. Throughout this phase of growth mitochondrial divisions keep pace with cytokinesis so that the population of mitochondria remains at essentially the minimal level. As the ciliates enter the stationary growth phase the mitochondria increase in number, become oval to spherical in shape, and some migrate into the cytoplasm. Intramitochondrial masses of various configurations appear at this time. Some of the mitochondria lying in the cytoplasm become incorporated into vacuoles. Within these vacuoles either a single mitochondrion appears or several mitochondria may be seen along with other cytoplasmic structures. Later in the stationary growth phase the contained mitochondria are dense and the tubules are more compact than normal. Various stages in disorganization of the mitochondria are observed in a single large vacuole. Cytochemical tests reveal the presence of acid phosphatase, suggesting that hydrolysis of the vacuolar contents occurs. Lipid droplets increase in number during the middle and late stationary phase of growth. These events are interpreted as being associated with the normal process of aging in T. pyriformis.

High Hydrostatic Pressure Come-Up Time and Yeast Viability

1998 ◽  
Vol 61 (12) ◽  
pp. 1657-1660 ◽  
Author(s):  
E. PALOU ◽  
A. LÓPEZ-MALO ◽  
G. V. BARBOSA-CÁNOVAS ◽  
J. WELTI-CHANES ◽  
P. M. DAVIDSON ◽  
...  
Keyword(s):  
Growth Phase ◽  
Growth Cycle ◽  
Stationary Growth Phase ◽  
Yeast Cells ◽  
Exponential Growth Phase ◽  
Stationary Growth ◽  
Survival Fraction ◽  
Zygosaccharomyces Bailii ◽  
Yeast Viability ◽  
Increased Sensitivity

The effects of the come-up time at selected pressures (50 to 689 MPa) on Saccharomyces cerevisiae and Zygosaccharomyces bailii viability were evaluated at 21°C. For Z. bailii the effects of the water activity (aw) of the suspension media and the stage of the growth cycle were also investigated. Pressure come-up times exerted an important effect on the yeast survival fraction, decreasing counts as pressure increased. An increased sensitivity to pressure treatments was observed with yeast cells from the exponential growth phase. Lethality increased as aw of the suspension media increased. For an aw of 0.98 and cells from the stationary growth phase, pressure treatments at less than 200 MPa had no effect on Z. bailii viability; however, no survivors (<10 CFU/ml) were observed in treatments applied only for the time needed to reach pressures greater than 517 MPa. Yeast survivor curves showed an excellent fit (r > 0.996) when described by a phenomenological model based on the Fermi equation, S(P) = 1/|1 + exp[(P − Pc)/k]|, where S(P) is the survival fraction, P is the pressure, Pc is a critical pressure corresponding to 50% survival, and k is a constant representing the steepness of the curve.

Copper Uptake by Penicillium brevicompactum

2001 ◽  
Vol 56 (9-10) ◽  
pp. 803-805 ◽  
Author(s):  
Kohshka Tsekova ◽  
Vera Dentcheva ◽  
Maria Ianis
Keyword(s):  
Growth Phase ◽  
Time Course ◽  
Stationary Growth Phase ◽  
Growth Time ◽  
Copper Binding ◽  
Copper Uptake ◽  
Logarithmic Growth Phase ◽  
Penicillium Brevicompactum ◽  
Straight Lines ◽  
Logarithmic Growth

Abstract Penicillium brevicompactum, Copper Uptake, Kinetics The copper binding properties of Penicillium brevicompactum biomass were influenced by growth phase of mycelium and concentration of copper in reaction mixtures. The efficiency of copper uptake increased with growth time and was largest at the mid-logarithmic growth phase. The time course of copper uptake was biphasic. Double reciprocal plots of absorption velocity of copper vs. copper concentration gave straight lines at concentration between 0.5 to 4 mᴍ . The apparent affinity of copper to the biomass of the stationary growth phase was the same as that of logarithmic growth phase and Km values were about 1.4 mᴍ . Pretreatment of the mycelium with glucose increased the amount of metal uptake about five times in comparison with the controls.

scholarly journals Subcellular localization of two different type-1 casein kinases from yeast.

1993 ◽  
Vol 40 (3) ◽  
pp. 405-410
Author(s):  
P Dukowski ◽  
R Szyszka ◽  
J Bednara
Keyword(s):  
Yeast Cell ◽  
Growth Phase ◽  
Stationary Growth Phase ◽  
Casein Kinase ◽  
Yeast Cells ◽  
Logarithmic Growth Phase ◽  
Casein Kinases ◽  
Logarithmic Growth ◽  
Cell Division Control

Specific antibodies directed against the two yeast type-1 casein kinases (CK1) were used to study the localization of both 45 kDa and 27 kDa casein kinase species in yeast cells by immunofluorescence. Our results indicate that the larger and smaller CK1 species are localised in different compartments of the yeast cell. The 45 kDa enzyme is present in the cytoplasm of the cell both during the logarithmic and stationary growth phase. The 27 kDa CK1 was found in the nucleus in the cells in logarithmic growth phase while the enzyme from the stationary phase was present in the cytoplasm. Our results suggest that the 27 kDa casein kinase may play some role in yeast cell division control by displacement from the nucleus to the cytoplasm.

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.

scholarly journals Conversion of Daidzein and Genistein by an Anaerobic Bacterium Newly Isolated from the Mouse Intestine

2008 ◽  
Vol 74 (15) ◽  
pp. 4847-4852 ◽  
Author(s):  
Anastasia Matthies ◽  
Thomas Clavel ◽  
Michael Gütschow ◽  
Wolfram Engst ◽  
Dirk Haller ◽  
...  
Keyword(s):  
Stationary Phase ◽  
Enzyme Induction ◽  
Growth Phase ◽  
Anaerobic Bacterium ◽  
Stationary Growth Phase ◽  
Gut Bacteria ◽  
Soy Isoflavones ◽  
Strictly Anaerobic ◽  
Stationary Growth ◽  
Mouse Intestine

ABSTRACT The metabolism of isoflavones by gut bacteria plays a key role in the availability and bioactivation of these compounds in the intestine. Daidzein and genistein are the most common dietary soy isoflavones. While daidzein conversion yielding equol has been known for some time, the corresponding formation of 5-hydroxy-equol from genistein has not been reported previously. We isolated a strictly anaerobic bacterium (Mt1B8) from the mouse intestine which converted daidzein via dihydrodaidzein to equol as well as genistein via dihydrogenistein to 5-hydroxy-equol. Strain Mt1B8 was a gram-positive, rod-shaped bacterium identified as a member of the Coriobacteriaceae. Strain Mt1B8 also transformed dihydrodaidzein and dihydrogenistein to equol and 5-hydroxy-equol, respectively. The conversion of daidzein, genistein, dihydrodaidzein, and dihydrogenistein in the stationary growth phase depended on preincubation with the corresponding isoflavonoid, indicating enzyme induction. Moreover, dihydrogenistein was transformed even more rapidly in the stationary phase when strain Mt1B8 was grown on either genistein or daidzein. Growing the cells on daidzein also enabled conversion of genistein. This suggests that the same enzymes are involved in the conversion of the two isoflavones.

scholarly journals The extracellular proteome of Rhizobium etli CE3 in exponential and stationary growth phase

2010 ◽  
Vol 8 (1) ◽  
pp. 51 ◽  
Author(s):  
Niurka Meneses ◽  
Guillermo Mendoza-Hernández ◽  
Sergio Encarnación
Keyword(s):  
Growth Phase ◽  
Stationary Growth Phase ◽  
Rhizobium Etli ◽  
Stationary Growth ◽  
Extracellular Proteome

Regeneration of protoplasts in Saccharomyces

1972 ◽  
Vol 18 (11) ◽  
pp. 1773-1775 ◽  
Author(s):  
M. M. Shahin
Keyword(s):  
Growth Phase ◽  
Transition Phase ◽  
Protoplast Formation ◽  
Logarithmic Growth Phase ◽  
High Degree ◽  
Logarithmic Growth

Protoplasts prepared from cells of different stages within the logarithmic growth phase and from transition phase showed different degrees of colony-forming ability. The cells yielding higher frequency of protoplast formation also gave protoplast with a high degree of colony-forming ability.

scholarly journals Proteomic Study of the Exponential-Stationary Growth Phase Transition in the Haloarchaea Natrialba magadii and Haloferax volcanii

PROTEOMICS ◽  
2018 ◽  
Vol 18 (14) ◽  
pp. 1800116 ◽  
Author(s):  
Micaela Cerletti ◽  
María Ines Giménez ◽  
Christian Tröetschel ◽  
Celeste D’ Alessandro ◽  
Ansgar Poetsch ◽  
...  
Keyword(s):  
Phase Transition ◽  
Growth Phase ◽  
Stationary Growth Phase ◽  
Haloferax Volcanii ◽  
Stationary Growth ◽  
Proteomic Study ◽  
Natrialba Magadii ◽  
Growth Phase Transition

Effect of Temperature on Growth and Alpha Toxin Production by Clostridium perfringens1

1979 ◽  
Vol 42 (11) ◽  
pp. 848-851 ◽  
Author(s):  
Y. PARK ◽  
E. M. MIKOLAJCIK
Keyword(s):  
Growth Phase ◽  
Incubation Temperature ◽  
Ground Beef ◽  
Population Level ◽  
Toxin Production ◽  
Stationary Growth Phase ◽  
Effect Of Temperature ◽  
Alpha Toxin ◽  
Stationary Growth ◽  
Incubation Temperatures

Growth and alpha toxin production by a strain of Clostridium perfringens was determined in Thioglycollate medium, beef broth with ground beef, and beef broth with ground beef and soy protein. Incubation temperatures ranged from 15 to 50 C. In Thioglycollate medium, maximum alpha toxin production occurred at 35 C and was 40 times greater than that observed at 45 C. However, generation time and maximum population were approximately the same at 35 and 45 C. At 15 C, a two log cycle reduction in viable counts occurred within 6 h. Irrespective of incubation temperature, alpha toxin levels in Thioglycollate medium declined as the incubation period was extended beyond the stationary growth phase. In the beef broth with ground beef system which was studied at 35 C only, the organism grew slower and produced less toxin than in Thioglycollate medium. The amount of alpha toxin detected was influenced to a greater extent by the incubation time and temperature, the holding time beyond the stationary growth phase, and the growth medium than by the population level of C. perfringens.

scholarly journals Various checkpoints prevent the synthesis ofStaphylococcus aureuspeptidoglycan hydrolase LytM in the stationary growth phase

RNA Biology ◽  
2016 ◽  
Vol 13 (4) ◽  
pp. 427-440 ◽  
Author(s):  
Efthimia Lioliou ◽  
Pierre Fechter ◽  
Isabelle Caldelari ◽  
Brian C. Jester ◽  
Sarah Dubrac ◽  
...  
Keyword(s):  
Growth Phase ◽  
Stationary Growth Phase ◽  
Stationary Growth
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