An analysis of the metabolism and cell wall composition of Candida albicans during germ-tube formation

1983 ◽  
Vol 29 (11) ◽  
pp. 1514-1525 ◽  
Author(s):  
Patrick A. Sullivan ◽  
Chiew Yoke Yin ◽  
Christopher Molloy ◽  
Matthew D. Templeton ◽  
Maxwell G. Shepherd
Keyword(s):  
Amino Acids ◽  
Cell Wall ◽  
Germ Tube ◽  
Dry Weight ◽  
Tube Formation ◽  
Cell Wall Composition ◽  
Yeast Cells ◽  
Tube Forming ◽  
Insoluble Glucan ◽  
Germ Tubes

The uptake of nutrients (glucose, glutamine, and N-acetylglucosamine), the intracellular concentrations of metabolites (glucose-6-phosphate, cyclic AMP, amino acids, trehalose, and glycogen) and cell wall composition were studied in Candida albicans. These analyses were carried out with exponential-phase, stationary-phase, and starved yeast cells, and during germ-tube formation. Germ tubes formed during a 3-h incubation of starved yeast cells (0.8 × 108 cells/mL) at 37 °C during which time the nutrients glucose plus glutamine or N-acetylglucosamine (2.5 mM of each) were completely utilized. Control incubations with these nutrients at 28 °C did not form germ tubes. Uptake of N-acetylglucosamine and glutamine was inhibited by cycloheximide which suggests that de novo protein synthesis was required for the induction of these uptake systems. The glucose-6-phosphate content varied from 0.4 nmol/mg dry weight for starved cells to 2–3 nmol/mg dry weight for growing yeast cells and germ tube forming cells. Trehalose content varied from 85 nmol/mg dry weight (growing yeast cells and germ tube forming cells) to 165 nmol/mg weight (stationary-phase cells). The glycogen content decreased during germ-tube formation (from 800 to 600 nmol glucose equivalent/mg dry weight) but increased (to 1000 nmol glucose equivalent/mg dry weight) in the control incubation of yeast cells. Cyclic AMP remained constant throughout germ-tube formation at 4–6 pmol/mg dry weight. The total amino acid pool was similar in exponential, starved, and germ tube forming cells but there were changes in the amounts of individual amino acids. The overall cell wall composition of yeast cells and germ tube forming cells were similar: lipid (2%, w/w); protein (3–6%), and carbohydrate (77–85%). The total carbohydrates were accounted for as the following fractions: alkali-soluble glucan (3–8%), mannan (20–23%), acid-soluble glucan (24–27%), and acid-insoluble glucan (18–26%). The relative amounts of the alkali-soluble and insoluble glucan changed during starvation of yeast cells, reinitiation of yeast-phase growth, and germ-tube formation. Analysis of the insoluble glucan fraction from cells labelled with [14C]glucose during germ-tube formation showed that the chitin content of the cell wall increased from 0.6% to 2.7% (w/w).

Germ tube induction in Candida albicans

1980 ◽  
Vol 26 (1) ◽  
pp. 21-26 ◽  
Author(s):  
M. G. Shepherd ◽  
Chiew Yoke Yin ◽  
S. P. Ram ◽  
P. A. Sullivan
Keyword(s):  
Candida Albicans ◽  
Germ Tube ◽  
Potassium Cyanide ◽  
Dry Weight ◽  
Tube Formation ◽  
Yeast Cells ◽  
Leucine Incorporation ◽  
Dna And Rna ◽  
Rna Content ◽  
Germ Tubes

A reproducible and simple system for the production of germ tubes from yeast cells of Candida albicans using glucose and glutamine as substrates has been described.During germ tube formation there was a doubling of the dry weight but the number of cells remained constant. Although the DNA content did not change for the first 4 h of germ tube formation, the RNA content more than doubled. The DNA and RNA content of C. albicans blastospores are 4.5 × 10−15 g per cell and 48 × 10−15 g per cell respectively.Nystatin, phenethyl alcohol, 2,4-dinitrophenol, azaserine, salicylhydroxamic acid, and 5-fluorocytosine were all effective inhibitors of germ tube formation. Cysteine, potassium cyanide, and polyoxin D did not prevent germination. The incorporation of both uracil and leucine occurred rapidly during germ tube formation. The inhibitors of RNA synthesis, actinomycin D, cordycepin, and daunomycin prevented germination and inhibited uracil incorporation. The translational inhibitors, trichodermin, aurin tricarboxylic acid, puromycin, and cyloheximide were effective in inhibiting both germ tube formation and leucine incorporation.

scholarly journals Rates of germ tube formation from growing and non-growing yeast cells ofCandida albicans

1991 ◽  
Vol 81 (1) ◽  
pp. 15-18 ◽  
Author(s):  
Arlene D.B. Buchan ◽  
Neil A.R. Gow
Keyword(s):  
Germ Tube ◽  
Tube Formation ◽  
Yeast Cells ◽  
Ofcandida Albicans

Carbon dioxide induces endotrophic germ tube formation in Candida albicans

1990 ◽  
Vol 36 (4) ◽  
pp. 249-253 ◽  
Author(s):  
Ruth C. Mock ◽  
Jordan H. Pollack ◽  
Tadayo Hashimoto
Keyword(s):  
Carbon Dioxide ◽  
Candida Albicans ◽  
Sodium Bicarbonate ◽  
Key Words ◽  
Germ Tube ◽  
Tube Formation ◽  
Chemical Inducers ◽  
Tube Emergence ◽  
Ph Range ◽  
Germ Tubes

Candida albicans formed germ tubes when exposed to air containing 5 to 15% carbon dioxide (CO2). The CO2-mediated germ tube formation occurred optimally at 37 °C in a pH range of 5.5 to 6.5. No germ tubes were produced at 25 °C, even when the optimal concentration of CO2 (10%) was present in the environment. The requirement of CO2 for germ tube formation could be partially substituted by sodium bicarbonate but not by N2. Carbon dioxide was required to be present throughout the entire course of germ tube emergence suggesting that its role is not limited to an initial triggering of morphogenic change. We suggest that carbon dioxide may be a common effector responsible for the germ tube promoting activity of certain chemical inducers for C. albicans. Key words: Candida albican germ tubes, CO2-induced germ tube formation, endotrophic germ tube formation.

Nutritional requirements for cell wall synthesis in Micrococcus lysodeikticus

1969 ◽  
Vol 15 (4) ◽  
pp. 327-334
Author(s):  
M. P. Hatton
Keyword(s):  
Amino Acids ◽  
Cell Wall ◽  
Glutamic Acid ◽  
Dry Weight ◽  
Defined Medium ◽  
Complete Medium ◽  
Magnesium Ions ◽  
Cell Wall Synthesis ◽  
Micrococcus Lysodeikticus ◽  
Total Dry Weight

Preferential cell wall synthesis in Micrococcus lysodeikticus, as determined by an increase in the dry weight of the cell wall, took place in a medium containing DL-glutamic acid, DL-alanine, L-lysine, glycine, magnesium ions, glucose and phosphate buffer, pH 7.0. Cell wall synthesis could not be completely dissociated from protein synthesis in the 'cell wall' medium. The cell wall synthesized in the defined medium accounted for 40–56% of the total dry weight increase of the cells. Chloramphenicol had no effect on cell wall synthesis. Incorporation of uracil and guanine in the medium did not result in any increase in the amount of cell wall synthesized. DL-Glutamic acid alone, or a mixture of the three amino acids DL-alanine, L-lysine, and glycine, were capable of replacing the four amino acids present in the complete medium, but under these conditions the total dry weight of cell wall synthesized was only 75% of that produced in the complete medium. There was no reduction in cell wall synthesis when L-glutamic acid replaced DL-glutamic acid, L-alanine replaced DL-alanine, or sucrose replaced glucose in the cell wall medium. Deprivation of magnesium ions produced the greatest decrease in wall synthesis; this was the most important single factor involved in cell wall synthesis which was studied in the present investigation. There was no observable change in the chemical composition of the cell wall synthesized in the 'wall' medium when compared to that synthesized by cells grown in a complex medium.

Differential expression of cytoplasmic proteins during yeast bud and germ tube formation in Candida albicans

1981 ◽  
Vol 27 (6) ◽  
pp. 580-585 ◽  
Author(s):  
Louise A. Brown ◽  
W. LaJean Chaffin
Keyword(s):  
Gene Expression ◽  
Candida Albicans ◽  
Germ Tube ◽  
Polyacrylamide Gel Electrophoresis ◽  
Tube Formation ◽  
Yeast Cells ◽  
Cytoplasmic Proteins ◽  
Specific Proteins ◽  
Major Shift ◽  
Dimorphic Yeast

Changes in the identity and quantity of proteins synthesized during morphogenesis may result from alterations in gene expression in the dimorphic yeast Candida albicans. Stationary phase yeast cells, upon resuming growth at 25 °C, form budding yeast and at 37 °C form germ tubes. In order to identify proteins associated with morphogenesis, we compared cytoplasmic proteins synthesized during germ tube and bud formation. Proteins synthesized during this period were labeled at four intervals with either [3H]leucine or [35S]methionine and separated by two-dimensional polyacrylamide gel electrophoresis. This study shows that, of the 230 proteins resolved on each gel, 5 were specific to the yeast morphology and 2 proteins showed reduction in net synthesis in the mycelial phase. There were, however, no mycelium-specific proteins at any labeling period. The majority of proteins were common to both morphologies and showed no major shift in number during resumption of growth. The observations reported here suggest that differential gene expression occurs during morphogenesis of C. albicans.

scholarly journals Deletion of Atg22 gene contributes to reduce programmed cell death induced by acetic acid stress in Saccharomyces cerevisiae

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Jingjin Hu ◽  
Yachen Dong ◽  
Wei Wang ◽  
Wei Zhang ◽  
Hanghang Lou ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acids ◽  
Cell Death ◽  
Cell Wall ◽  
Acetic Acid ◽  
Programmed Cell Death ◽  
Cell Wall Integrity ◽  
Yeast Cells ◽  
Death Process ◽  
Lignocellulosic Biofuel

Abstract Background Programmed cell death (PCD) induced by acetic acid, the main by-product released during cellulosic hydrolysis, cast a cloud over lignocellulosic biofuel fermented by Saccharomyces cerevisiae and became a burning problem. Atg22p, an ignored integral membrane protein located in vacuole belongs to autophagy-related genes family; prior study recently reported that it is required for autophagic degradation and efflux of amino acids from vacuole to cytoplasm. It may alleviate the intracellular starvation of nutrition caused by Ac and increase cell tolerance. Therefore, we investigate the role of atg22 in cell death process induced by Ac in which attempt is made to discover new perspectives for better understanding of the mechanisms behind tolerance and more robust industrial strain construction. Results In this study, we compared cell growth, physiological changes in the absence and presence of Atg22p under Ac exposure conditions. It is observed that disruption and overexpression of Atg22p delays and enhances acetic acid-induced PCD, respectively. The deletion of Atg22p in S. cerevisiae maintains cell wall integrity, and protects cytomembrane integrity, fluidity and permeability upon Ac stress by changing cytomembrane phospholipids, sterols and fatty acids. More interestingly, atg22 deletion increases intracellular amino acids to aid yeast cells for tackling amino acid starvation and intracellular acidification. Further, atg22 deletion upregulates series of stress response genes expression such as heat shock protein family, cell wall integrity and autophagy. Conclusions The findings show that Atg22p possessed the new function related to cell resistance to Ac. This may help us have a deeper understanding of PCD induced by Ac and provide a new strategy to improve Ac resistance in designing industrial yeast strains for bioethanol production during lignocellulosic biofuel fermentation.

Germ-tube production by Candida albicans in minimal liquid culture media

1971 ◽  
Vol 17 (7) ◽  
pp. 851-856 ◽  
Author(s):  
D. N. Mardon ◽  
I. S. K. Hurst ◽  
E. Balish
Keyword(s):  
Candida Albicans ◽  
Butyric Acid ◽  
Germ Tube ◽  
Culture Medium ◽  
Culture Media ◽  
Tube Formation ◽  
Gamma Amino Butyric Acid ◽  
Tube Production ◽  
Amino Butyric Acid ◽  
Germ Tubes

Candida albicans formed germ tubes within 3 h at 37C in a glucose–salts–biotin (GSB) medium containing L-alpha-amino-n-butyric acid as the nitrogen source. Optimal germ-tube production was obtained when the inoculum was grown on Sabouraud dextrose agar. The GSB medium containing L-alpha-amino-n-butyric acid promoted germ-tube formation more effectively than GSB medium plus gamma-amino-butyric acid or Sabouraud dextrose broth.Carbon-14 incorporation studies revealed that during germ-tube formation (0–4 h) the 3 carbon of alpha-amino-n-butyric acid was incorporated intracellularly to a greater extent than the 1 carbon. However, during blastospore formation (5–16 h), this difference was less pronounced.When six other Candida species were grown in GSB plus L-alpha-amino-n-butyric acid medium, few germ tubes were observed with the exception of one Candida stellatoidea strain. However, even this strain of C. stellatoidea produced far fewer germ tubes in this minimal culture medium than any strain of C. albicans tested.

SYNTHESIS OF MACROMOLECULES IN MAIZE ROOT TIPS

1967 ◽  
Vol 45 (4) ◽  
pp. 385-394 ◽  
Author(s):  
Ann Oaks
Keyword(s):  
Amino Acids ◽  
Cell Wall ◽  
Continuous Flow ◽  
Flow System ◽  
Dry Weight ◽  
Maximal Rate ◽  
Root Tips ◽  
Corn Roots ◽  
Rate Of Increase ◽  
Cell Wall Carbohydrates

Corn roots grown in a glucose–salts medium in a continuous flow system suffered an initial loss of protein before an increase was observed. A maximal rate of increase in cell-wall carbohydrates was achieved after 20 hours in culture. There was some loss in RNA while the increase in DNA was slight. A synthetic mixture of 15 L-amino acids enhanced the growth (defined as increase in length, dry weight, or alcohol-insoluble nitrogen) of glucose-grown roots. With this enriched medium there was a slight increase of protein over the initial 20-hour period and a faster rate of increase after this time. No lag in the increase in cell-wall carbohydrates was observed. Despite these symptoms of better growth the level of DNA was not improved by the addition of the amino acids and the RNA content was actually lower than in the glucose-grown roots. Although the level of RNA was less in cultured than in normal roots, ribosomal and soluble RNA accounted for similar proportions of the total RNA in each case.

A putative dual-specific protein phosphatase encoded by YVH1 controls growth, filamentation and virulence in Candida albicans

Microbiology ◽  
2005 ◽  
Vol 151 (7) ◽  
pp. 2223-2232 ◽  
Author(s):  
Nozomu Hanaoka ◽  
Takashi Umeyama ◽  
Keigo Ueno ◽  
Kenji Ueda ◽  
Teruhiko Beppu ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Candida Albicans ◽  
Cell Cycle Progression ◽  
Germ Tube ◽  
Hyphal Growth ◽  
Tube Formation ◽  
Yeast Cells ◽  
Nucleotide Polymorphisms ◽  
Wild Type ◽  
Cycle Progression

In response to stimulants, such as serum, the yeast cells of the opportunistic fungal pathogen Candida albicans form germ tubes, which develop into hyphae. Yvh1p, one of the 29 protein phosphatases encoded in the C. albicans genome, has 45 % identity with the dual-specific phosphatase Yvh1p of the model yeast Saccharomyces cerevisiae. In this study, Yvh1p expression was not observed during the initial step of germ tube formation, although Yvh1p was expressed constitutively in cell cycle progression of yeast or hyphal cells. In an attempt to analyse the function of Yvh1p phosphatase, the complete ORFs of both alleles were deleted by replacement with hph200–URA3–hph200 and ARG4. Although YVH1 has nine single-nucleotide polymorphisms in its coding sequence, both YVH1 alleles were able to complement the YVH1 gene disruptant. The vegetative growth of Δyvh1 was significantly slower than the wild-type. The hyphal growth of Δyvh1 on agar, or in a liquid medium, was also slower than the wild-type because of the delay in nuclear division and septum formation, although germ tube formation was similar between the wild-type and the disruptant. Despite the slow hyphal growth, the expression of several hypha-specific genes in Δyvh1 was not delayed or repressed compared with that of the wild-type. Infection studies using mouse models revealed that the virulence of Δyvh1 was less than that of the wild-type. Thus, YVH1 contributes to normal vegetative yeast or hyphal cell cycle progression and pathogenicity, but not to germ tube formation.

Rates of germ tube formation from growing and non-growing yeast cells of Candida albicans

1991 ◽  
Vol 81 (1) ◽  
pp. 15-18 ◽  
Author(s):  
A Buchan
Keyword(s):  
Candida Albicans ◽  
Germ Tube ◽  
Tube Formation ◽  
Yeast Cells
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