scholarly journals The mannophosphoinositides of Corynebacterium aquaticum

1975 ◽  
Vol 148 (2) ◽  
pp. 253-258 ◽  
Author(s):  
J A Hackett ◽  
P J Brennan
Keyword(s):  
Stationary Phase ◽  
Exponential Growth ◽  
Growth Cycle ◽  
Exponential Phase ◽  
Late Stationary Phase ◽  
Late Exponential Phase

Besides the monomannophosphoinositide previously reported in Corynebacterium aquaticum small amounts of other, apparently more glycosylated, mannophosphoinositides have been identified in stationary phase cells. Moreover, by labelling cells with [32P]Pi, phosphatidylinositol was found, comprising about 1.5% of the stationary-phase phospholipids. 2. Pulse-chase experiments performed on cells in the late exponential phase of growth further suggested the sequence phosphatidylinositol leads to monomannophosphoinositide as the first step in the biosynthesis of the mannophosphoinositides. 3. Di-and tri-mannophosphoinositides are apparently the main mannophosphoinositides present during exponential growth. Monomannophosphoinositide predominates only in late stationary phase; in the earlier stationary phase, phosphatidylinositol comprises 50% of the phosphoinositide lipid, and tetramannophosphoinositide constitutes much of the remainder. 4. The metabolism and functions of the mannophosphoinositides are discussed, particularly in relation to changes in their composition throughout the growth cycle.

scholarly journals Peptidoglycan Recycling in Gram-Positive Bacteria Is Crucial for Survival in Stationary Phase

mBio ◽  
2016 ◽  
Vol 7 (5) ◽  
Author(s):  
Marina Borisova ◽  
Rosmarie Gaupp ◽  
Amanda Duckworth ◽  
Alexander Schneider ◽  
Désirée Dalügge ◽  
...  
Keyword(s):  
Cell Wall ◽  
Stationary Phase ◽  
Exponential Growth ◽  
Model Organisms ◽  
Exponential Growth Phase ◽  
Rich Medium ◽  
Late Stationary Phase ◽  
Gram Positive ◽  
Term Survival ◽  
Gram Positive Bacteria

ABSTRACTPeptidoglycan recycling is a metabolic process by which Gram-negative bacteria reutilize up to half of their cell wall within one generation during vegetative growth. Whether peptidoglycan recycling also occurs in Gram-positive bacteria has so far remained unclear. We show here that three Gram-positive model organisms,Staphylococcus aureus,Bacillus subtilis, andStreptomyces coelicolor, all recycle the sugarN-acetylmuramic acid (MurNAc) of their peptidoglycan during growth in rich medium. They possess MurNAc-6-phosphate (MurNAc-6P) etherase (MurQ inE. coli) enzymes, which are responsible for the intracellular conversion of MurNAc-6P toN-acetylglucosamine-6-phosphate andd-lactate. By applying mass spectrometry, we observed accumulation of MurNAc-6P in MurNAc-6P etherase deletion mutants but not in either the isogenic parental strains or complemented strains, suggesting that MurQ orthologs are required for the recycling of cell wall-derived MurNAc in these bacteria. Quantification of MurNAc-6P in ΔmurQcells ofS. aureusandB. subtilisrevealed small amounts during exponential growth phase (0.19 nmol and 0.03 nmol, respectively, per ml of cells at an optical density at 600 nm [OD600] of 1) but large amounts during transition (0.56 nmol and 0.52 nmol) and stationary (0.53 nmol and 1.36 nmol) phases. The addition of MurNAc to ΔmurQcultures greatly increased the levels of intracellular MurNAc-6P in all growth phases. The ΔmurQmutants ofS. aureusandB. subtilisshowed no growth deficiency in rich medium compared to the growth of the respective parental strains, but intriguingly, they had a severe survival disadvantage in late stationary phase. Thus, although peptidoglycan recycling is apparently not essential for the growth of Gram-positive bacteria, it provides a benefit for long-term survival.IMPORTANCEThe peptidoglycan of the bacterial cell wall is turned over steadily during growth. As peptidoglycan fragments were found in large amounts in spent medium of exponentially growing Gram-positive bacteria, their ability to recycle these fragments has been questioned. We conclusively showed recycling of the peptidoglycan component MurNAc in different Gram-positive model organisms and revealed that a MurNAc-6P etherase (MurQ or MurQ ortholog) enzyme is required in this process. We further demonstrated that recycling occurs predominantly during the transition to stationary phase inS. aureusandB. subtilis, explaining why peptidoglycan fragments are found in the medium during exponential growth. We quantified the intracellular accumulation of recycling products in MurNAc-6P etherase gene mutants, revealing that about 5% and 10% of the MurNAc of the cell wall per generation is recycled inS. aureusandB. subtilis, respectively. Importantly, we showed that MurNAc recycling and salvaging does not sustain growth in these bacteria but is used to enhance survival during late stationary phase.

scholarly journals Translocation of mycobacillin synthetase in Bacillus subtilis

1985 ◽  
Vol 225 (3) ◽  
pp. 639-643 ◽  
Author(s):  
N K Mukhopadhyay ◽  
S K Ghosh ◽  
S Majumder ◽  
S K Bose
Keyword(s):  
Protein Synthesis ◽  
Bacillus Subtilis ◽  
Stationary Phase ◽  
Exponential Phase ◽  
High Rate ◽  
Synthetase Activity ◽  
Late Exponential Phase ◽  
Extracellular Release ◽  
Particulate Form ◽  
Membrane Bound

The extracellular release of mycobacillin from Bacillus subtilis first occurred in the medium at the onset of stationary phase and continued at a high rate even after 6 days. Mycobacillin synthetase activity appeared earlier than late-exponential phase in the cytosol of producer cells and was not sedimentable even at 105 000 g. The activity then quickly reached the maximum late in the stationary phase. With further increase in the age of the culture, the activity gradually disappeared from the cytosol, to reappear concomitantly in the membrane in an insoluble particulate form, even in absence of protein synthesis. The membrane-bound synthetase activity was sedimentable at 10 000 g and was fairly active even after 5 days.

scholarly journals Inositol transport in Saccharomyces cerevisiae is regulated by transcriptional and degradative endocytic mechanisms during the growth cycle that are distinct from inositol-induced regulation.

1996 ◽  
Vol 7 (1) ◽  
pp. 81-89 ◽  
Author(s):  
K S Robinson ◽  
K Lai ◽  
T A Cannon ◽  
P McGraw
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Stationary Phase ◽  
Exponential Growth ◽  
Growth Cycle ◽  
Endocytic Pathway ◽  
Negative Regulator ◽  
Lag Phase ◽  
Free Medium ◽  
Uptake Activity ◽  
Inositol Uptake

Regulation of inositol uptake activity in Saccharomyces cerevisiae during the growth cycle was examined. Activity increased as the cell population transited from lag phase to exponential growth, and continued to increase until late exponential phase. The increase in activity was due to increased transcription of the ITR1 gene and synthesis of the Itr1 permease. When the culture reached stationary phase, uptake activity decreased and dropped to a minimum within 4 h. The decrease was due to repression of ITR1 transcription, independent of the negative regulator Opi1p, and degradation of the existing permease. Degradation depended on delivery of the permease to the vacuole through the END3/END4 endocytic pathway. During exponential growth in inositol-containing medium the permease is also rapidly degraded, whereas in inositol-free medium the permease is highly stable. Rapid degradation of the permease at stationary phase occurred in inositol-free medium, indicating that there are two distinct mechanisms that trigger endocytosis and degradation in response to different physiological stimuli. In addition, the level of the enzyme required for inositol biosynthesis, inositol-1-phosphate synthase, encoded by INO1, is not reduced in stationary-phase cells, and this contrast in the regulation of inositol supply is discussed.

Identification d'une nucléotide pyrophosphatase exocellulaire dans le milieu de culture de Streptomyces mediterranei ME/R 17

1979 ◽  
Vol 25 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Gérard Pellon ◽  
Georges Michel
Keyword(s):  
Enzyme Preparation ◽  
Culture Medium ◽  
Deae Cellulose ◽  
Growth Cycle ◽  
Exponential Phase ◽  
Nucleotidase Activity ◽  
Late Exponential Phase ◽  
Nucleotide Pyrophosphatase ◽  
Pyrophosphatase Activity ◽  
Positive Effect

An exocellular pyrophosphatase, active on the nucleotide precursors of peptidoglycans, has been found in the culture medium of Streptomyces mediterranei ME/R 17. This enzyme was separated from the DD-carboxypeptidase by batchwise adsorption on DEAE cellulose. The pyrophosphatase had no strict substrate requirements, it hydrolyzed various UDP-sugar substrates: UDP-GlcNAc. UDP-MurNAc and UDP-MurNAc peptides, giving rise to the corresponding sugar phosphate and to UMP. The enzyme preparation also contained a 5′-nucleotidase activity and UMP was further split to give uridine. This nucleotidase activity was inhibited by potassium tetraborate. Both cytoplasmic and particulate preparations from cells of S. mediterranei also contained a pyrophosphatase activity while only the particulate fractions showed the DD-carboxypeptidase activity.The pyrophosphatase excretion was tested during the growth cycle. The activity of the enzyme showed a constant increase throughout the exponential growth and a stronger increase in the late exponential phase. Such a result could be correlated with a consumption of the nutrients in the culture medium, in fact a relatively poor culture medium had a strong positive effect upon the production of the exocellular pyrophosphatase.

Temporal Expression of Staphylococcal Enterotoxin H in Comparison with Accessory Gene Regulator–Dependent and –Independent Enterotoxins

2012 ◽  
Vol 75 (2) ◽  
pp. 238-244 ◽  
Author(s):  
ELŻBIETA LIS ◽  
MAGDALENA PODKOWIK ◽  
JAROSŁAW BYSTROŃ ◽  
TADEUSZ STEFANIAK ◽  
JACEK BANIA
Keyword(s):  
Stationary Phase ◽  
Expression Profile ◽  
Exponential Phase ◽  
Staphylococcal Enterotoxin ◽  
Enzyme Linked Immunosorbent Assay ◽  
Temporal Expression ◽  
Accessory Gene ◽  
Late Exponential Phase ◽  
Accessory Gene Regulator ◽  
First Time

Using sandwich enzyme-linked immunosorbent assay (ELISA), the production of staphylococcal enterotoxin (SE) H was determined in 22 Staphylococcus aureus isolates bearing the seh gene. Samples of supernatants were taken at four time points corresponding to exponential phase (optical density at 600 nm [OD600] 0.3 to 0.6), late exponential phase (OD600 2 to 4), early stationary phase (OD600 4 to 6), and late stationary phase (OD600 7 to 12). In four isolates, SEH was detectable at a very low level at the first time point. In 18 isolates, the earliest SEH production was detected in the late exponential phase. For all isolates, there was an increase of SEH concentration with time. Western blot analysis revealed that SEH production, similar to SEA, started in the early exponential phase (OD600 ~ 0.5). Isolates with high SEH productivity, as measured by ELISA, demonstrated a higher seh transcription as well. sec transcription was induced in the stationary phase. An induction in the sea transcript was observed during mid- to late exponential phase. Expression profile of seh was similar to that of sea. We showed that the seh expression profile is similar to that of Agr-independent sea and not to that of Agr-dependent sec genes. SEH can be effectively expressed at low bacterial counts, meaning that even in an environment not favorable for S. aureus growth, seh-bearing strains can pose a risk for food safety.

The occurrence of cell-associated enterotoxin B in Staphylococcus aureus

1976 ◽  
Vol 22 (9) ◽  
pp. 1215-1221 ◽  
Author(s):  
Richard D. Miller ◽  
Daniel Y. C. Fung
Keyword(s):  
Staphylococcus Aureus ◽  
Stationary Phase ◽  
Cytoplasmic Membrane ◽  
Exponential Phase ◽  
Total Cell ◽  
Late Exponential Phase ◽  
Hypertonic Medium ◽  
Osmotic Lysis ◽  
Enterotoxin B

Cell-associated enterotoxin B was detected in lysates of cells of Staphylococcus aureus S-6 and 4916 disrupted by sonication or lysostaphin treatment. As much as 67% of this total cell-associated toxin was surface-bound, located outside the cytoplasmic membrane, and was released during protoplasting of this organism by lysostaphin treatment in hypertonic medium. The remainder of the cell-associated toxin was termed cytoplasmic and was released during osmotic lysis of the protoplasts. Levels of cell-associated toxin as a function of the age of the cells showed a rapid increase in both surface-bound, cytoplasmic, and total cell-associated toxin levels during the period of active toxin synthesis (late exponential phase of growth). These cell-associated toxin levels then reached a peak as the culture entered stationary phase, at a time corresponding to a decrease in the rate of toxin synthesis, and decreased slowly thereafter.

scholarly journals Growth-related fluctuation in messenger RNA utilization in animal cells.

1978 ◽  
Vol 79 (1) ◽  
pp. 85-86 ◽  
Author(s):  
G T Lee ◽  
D L Engelhardt
Keyword(s):  
Stationary Phase ◽  
Messenger Rna ◽  
Protein Biosynthesis ◽  
Growth Cycle ◽  
Exponential Phase ◽  
Wheat Germ Extract ◽  
Animal Cells ◽  
Translational Initiation ◽  
Large Size ◽  
Polyadenylated Rna

Monkey fibroblasts maintained in culture regulate their levels of intracellular protein throughout the growth cycle by means of variations in the rate of protein biosynthesis. Cytoplasmic mRNA in stationary phase cells was compared to that in exponential phase cells. In stationary phase cells 56% of the cytoplasmic polyadenylated RNA was found in the 40--90S postpolysomal region of sucrose sedimentation gradients, while only 23% was found in this region in exponential phase cells. Analysis of electron micrographs of sectioned exponential and stationary phase cells revealed that this shift in polyadenylated RNA location is accompanied by a loss of polysome-like aggregates of ribosomes. Most if not all of this species of postpolysomal polyadenylated RNA is not being translated by single ribosomes since no detectable amounts of nascent peptide were present in this region. This nonpolysomal polyadenylated RNA is comparable in size to polysomal polyadenylated RNA. The length of the 3'-poly(A) tract was also comparable for these two species. The extent of capping of poly(A)-containing molecules was also comparable for these two species. The template activity of nonpolysomal RNA in a wheat germ extract was comparable to that of polysomal RNA. The peptides produced by these two preparations were of a similar large size. Furthermore, most of the nonpolysomal polyadenylated RNA of stationary phase cells was driven into polysomes in the presence of a low dose of cycloheximide. Therefore, we conclude that the untranslated mRNA that accumulates in stationary phase cells is structurally intact, is fully capable of being translated, and is not being translated due to the operation of a translational initiation block.

scholarly journals Role of mRNA Stability in Growth Phase Regulation of Gene Expression in the Group A Streptococcus

2006 ◽  
Vol 189 (5) ◽  
pp. 1866-1873 ◽  
Author(s):  
Timothy C. Barnett ◽  
Julia V. Bugrysheva ◽  
June R. Scott
Keyword(s):  
Gene Expression ◽  
Stationary Phase ◽  
Growth Phase ◽  
Group A Streptococcus ◽  
Exponential Phase ◽  
Northern Hybridization ◽  
Late Exponential Phase ◽  
Group A ◽  
Phase Regulation ◽  
The Stability

ABSTRACT The impressive disease spectrum of Streptococcus pyogenes (the group A streptococcus [GAS]) is believed to be determined by its ability to modify gene expression in response to environmental stimuli. Virulence gene expression is controlled tightly by several different transcriptional regulators in this organism. In addition, expression of most, if not all, GAS genes is determined by a global mechanism dependent on growth phase. To begin an analysis of growth-phase regulation, we compared the transcriptome 2 h into stationary phase to that in late exponential phase of a serotype M3 GAS strain. We identified the arc transcript as more abundant in stationary phase in addition to the sag and sda transcripts that had been previously identified. We found that in stationary phase, the stability of sagA, sda, and arcT transcripts increased dramatically. We found that polynucleotide phosphorylase (PNPase [encoded by pnpA]) is rate limiting for decay of sagA and sda transcripts in late exponential phase, since the stability of these mRNAs was greater in a pnpA mutant, while stability of control mRNAs was unaffected by this mutation. Complementation restored the wild-type decay rate. Furthermore, in a pnpA mutant, the sagA mRNA appeared to be full length, as determined by Northern hybridization. It seems likely that mRNAs abundant in stationary phase are insensitive to the normal decay enzyme(s) and instead require PNPase for this process. It is possible that PNPase activity is limited in stationary phase, allowing persistence of these important virulence factor transcripts at this phase of growth.

Measurement of Primary Productivity in Dense Algal Cultures

1983 ◽  
Vol 40 (6) ◽  
pp. 807-810 ◽  
Author(s):  
S-R. Gentner
Keyword(s):  
Primary Productivity ◽  
Growth Cycle ◽  
Exponential Phase ◽  
Scintillation Counting ◽  
Late Exponential Phase ◽  
Limited Sample ◽  
Productivity Measurement ◽  
Limited Sample Size ◽  
Scenedesmus Acutus ◽  
Algal Cultures

The 14C-bicarbonate method of primary productivity measurement was modified for dense algal cultures by the addition of NaHCO3 to avoid exhaustion of carbon source. Using this method plus a modified procedure for scintillation counting of limited sample size, six species of chlorophyean algae were studied daily throughout the growth cycle. Scenedesmus acutus was the most productive with a peak productivity of 5.3 mg C∙L−1∙h−1 at 9.7 × 103 lx during late exponential phase. Peak productivity values (mg C∙L−1∙h−1) for the other species were 2 for Chlorella vulgaris, 2.3 for Ankistrodesmus braunii, and 3.4, 3.5, and 3.6 mg C∙L−1∙h−1 for Scenedesmus basiliensis, S. bijugatus, and S. parisiensis, respectively.

Wall turnover deficiency of Bacillus subtilis Nil5 is due to a decrease in teichoic acid

1987 ◽  
Vol 33 (6) ◽  
pp. 566-568 ◽  
Author(s):  
Ljubiša Vitković
Keyword(s):  
Cell Wall ◽  
Bacillus Subtilis ◽  
Stationary Phase ◽  
Phosphorus Content ◽  
Teichoic Acid ◽  
Exponential Phase ◽  
Standard Strain ◽  
Late Exponential Phase ◽  
Wall Teichoic Acid

Bacillus subtilis Ni15 is deficient in cell wall turnover. This deficiency is removed if the medium contains 0.2 M NaCl, which does not affect growth. The levels of amidase and glucosaminidase, the most likely enzymes involved in turnover, were, in stationary phase Nil5 cells, similar to those in late-exponential phase cells of a standard strain. The Nil5 enzymes were not salt sensitive. However, the Nil5 walls contained 4.7-fold less phosphorus than the walls of the standard strain. Since the phosphorus content of B. subtilis walls reflects the level of teichoic acid, it is proposed that the turnover deficiency of this strain is due to a decrease in wall teichoic acid.

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