scholarly journals Temporal Expression of the Bacillus subtilis secAGene, Encoding a Central Component of the Preprotein Translocase

1999 ◽  
Vol 181 (2) ◽  
pp. 493-500 ◽  
Author(s):  
Markus Herbort ◽  
Michael Klein ◽  
Erik H. Manting ◽  
Arnold J. M. Driessen ◽  
Roland Freudl
Keyword(s):  
Bacillus Subtilis ◽  
Growth Phase ◽  
Exponential Growth ◽  
De Novo ◽  
Stationary Growth Phase ◽  
Extracellular Proteins ◽  
Exponential Growth Phase ◽  
Central Component ◽  
Temporal Expression ◽  
Stationary Growth

ABSTRACT In Bacillus subtilis, the secretion of extracellular proteins strongly increases upon transition from exponential growth to the stationary growth phase. It is not known whether the amounts of some or all components of the protein translocation apparatus are concomitantly increased in relation to the increased export activity. In this study, we analyzed the transcriptional organization and temporal expression of the secA gene, encoding a central component of the B. subtilis preprotein translocase. We found that secA and the downstream gene (prfB) constitute an operon that is transcribed from a vegetative (ςA-dependent) promoter located upstream ofsecA. Furthermore, using different independent methods, we found that secA expression occurred mainly in the exponential growth phase, reaching a maximal value almost precisely at the transition from exponential growth to the stationary growth phase. Following to this maximum, the de novo transcription ofsecA sharply decreased to a low basal level. Since at the time of maximal secA transcription the secretion activity of B. subtilis strongly increases, our results clearly demonstrate that the expression of at least one of the central components of the B. subtilis protein export apparatus is adapted to the increased demand for protein secretion. Possible mechanistic consequences are discussed.

scholarly journals CcpA-Independent Regulation of Expression of the Mg2+-Citrate Transporter Gene citM by Arginine Metabolism in Bacillus subtilis

2003 ◽  
Vol 185 (3) ◽  
pp. 854-859 ◽  
Author(s):  
Jessica B. Warner ◽  
Christian Magni ◽  
Juke S. Lolkema
Keyword(s):  
Bacillus Subtilis ◽  
Growth Phase ◽  
Exponential Growth ◽  
Stationary Growth Phase ◽  
Luria Bertani ◽  
Transition Phase ◽  
Exponential Growth Phase ◽  
Uptake System ◽  
Regulation Of Expression ◽  
Citrate Transporter

ABSTRACT Transcriptional regulation of the Mg2+-citrate transporter, CitM, the main citrate uptake system of Bacillus subtilis, was studied during growth in rich medium. Citrate in the growth medium was required for induction under all growth conditions. In Luria-Bertani medium containing citrate, citM expression was completely repressed during the exponential growth phase, marginally expressed in the transition phase, and highly expressed in the stationary growth phase. The repression was relieved when the cells were grown in spent Luria-Bertani medium. The addition of a mixture of 18 amino acids restored repression. l-Arginine in the mixture appeared to be solely responsible for the repression, and ornithine appeared to be an equally potent repressor of citM expression. Studies of mutant strains deficient in RocR and SigL, proteins required for the expression of the enzymes of the arginase pathway, confirmed that uptake into the cell and, most likely, conversion of arginine to ornithine were required for repression. Arginine-mediated repression was independent of a functional CcpA, the global regulator protein in carbon catabolite repression (CCR). Nevertheless, CCR-mediated repression was the major mechanism controlling the expression during exponential growth, while the newly described, CcpA-independent arginine-mediated repression was specifically apparent during the transition phase of growth.

Construction of a [NiFe]-hydrogenase deletion mutant of Desulfovibrio vulgaris Hildenborough

2005 ◽  
Vol 33 (1) ◽  
pp. 59-60 ◽  
Author(s):  
A. Goenka ◽  
J.K. Voordouw ◽  
W. Lubitz ◽  
W. Gärtner ◽  
G. Voordouw
Keyword(s):  
Growth Phase ◽  
Exponential Growth ◽  
Deletion Mutant ◽  
Stationary Growth Phase ◽  
Exponential Growth Phase ◽  
Desulfovibrio Vulgaris ◽  
Wild Type ◽  
Stationary Growth ◽  
Desulfovibrio Vulgaris Hildenborough ◽  
Mutant Cells

A mutant of Desulfovibrio vulgaris Hildenborough lacking a gene for [NiFe] hydrogenase was generated. Growth studies, performed for the mutant in comparison with the wild-type, showed no strong differences during the exponential growth phase. However, the mutant cells died more rapidly in the stationary growth phase.

scholarly journals Azithromycin Exhibits Bactericidal Effects on Pseudomonas aeruginosa through Interaction with the Outer Membrane

2005 ◽  
Vol 49 (4) ◽  
pp. 1377-1380 ◽  
Author(s):  
Yoshifumi Imamura ◽  
Yasuhito Higashiyama ◽  
Kazunori Tomono ◽  
Koichi Izumikawa ◽  
Katsunori Yanagihara ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Outer Membrane ◽  
Growth Phase ◽  
Exponential Growth ◽  
Divalent Cations ◽  
Stationary Growth Phase ◽  
Exponential Growth Phase ◽  
Stationary Growth ◽  
Outer Membranes ◽  
Bactericidal Effects

ABSTRACT The aim of the present study was to elucidate the effect of the macrolide antibiotic azithromycin on Pseudomonas aeruginosa. We studied the susceptibility to azithromycin in P. aeruginosa PAO1 using a killing assay. PAO1 cells at the exponential growth phase were resistant to azithromycin. In contrast, PAO1 cells at the stationary growth phase were sensitive to azithromycin. The divalent cations Mg2+ and Ca2+ inhibited this activity, suggesting that the action of azithromycin is mediated by interaction with the outer membranes of the cells, since the divalent cations exist between adjacent lipopolysaccharides (LPSs) and stabilize the outer membrane. The divalent cation chelator EDTA behaved in a manner resembling that of azithromycin; EDTA killed more PAO1 in the stationary growth phase than in the exponential growth phase. A 1-N-phenylnaphthylamine assay showed that azithromycin interacted with the outer membrane of P. aeruginosa PAO1 and increased its permeability while Mg2+ and Ca2+ antagonized this action. Our results indicate that azithromycin directly interacts with the outer membrane of P. aeruginosa PAO1 by displacement of divalent cations from their binding sites on LPS. This action explains, at least in part, the effectiveness of sub-MICs of macrolide antibiotics in pseudomonal chronic airway infection.

Occurrence of “Stress"-Proteins in Yeast after Heat-Shock, Acrylonitrile Treatment and during the Stationary Growth Phase

1985 ◽  
Vol 40 (1-2) ◽  
pp. 26-28 ◽  
Author(s):  
Ulrich Pfeffer ◽  
Bernd Schulz-Harder
Keyword(s):  
Heat Shock ◽  
Growth Phase ◽  
Exponential Growth ◽  
Stress Proteins ◽  
Stationary Growth Phase ◽  
Yeast Cells ◽  
Exponential Growth Phase ◽  
Stationary Growth ◽  
Molecular Weights

The response of yeast cells to different kinds of “stress” is not identical. Cells of the stationary growth phase synthesize three new proteins of molecular weights 68, 27 and 24 kD, compared with cells of the exponential growth phase, while heat-shocked cells exhibit new proteins of 100, 90. 84, 70 and 24 kD. After treatment with acrylonitrile two new proteins with molecular weights of 70 and 46 kD appear. However, all three kinds of “stress” lead to the induction of a ribonuclease.

Bacillus subtilis AprX involved in degradation of a heterologous protein during the late stationary growth phase

2007 ◽  
Vol 104 (2) ◽  
pp. 135-143 ◽  
Author(s):  
Takeko Kodama ◽  
Keiji Endo ◽  
Kazuhisa Sawada ◽  
Katsutoshi Ara ◽  
Katsuya Ozaki ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Growth Phase ◽  
Heterologous Protein ◽  
Stationary Growth Phase ◽  
Stationary Growth

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.

Induction of autolysis in Bacillus subtilis by ochratoxin A

1978 ◽  
Vol 24 (5) ◽  
pp. 563-568 ◽  
Author(s):  
U. Singer ◽  
R. Röschenthaler
Keyword(s):  
Cell Wall ◽  
Protein Synthesis ◽  
Bacillus Subtilis ◽  
Ochratoxin A ◽  
Optical Density ◽  
Growth Phase ◽  
Exponential Growth ◽  
Rna Synthesis ◽  
Exponential Growth Phase ◽  
Cell Wall Synthesis

Ochratoxin A (OTA) added during the exponential growth phase at a concentration higher than 12 μg/ml caused autolysis of Bacillus subtilis. Optical density of cultures decreased, and at higher concentrations the cultures became sterile. Optimum OTA-induced lysis was about pH 5. At concentrations below 10 μg/ml, protein synthesis was inhibited more strongly than RNA synthesis. Cell wall synthesis was also strongly inhibited. A fraction extracted from the lysates had the property of a lysis inhibitor. The relevance of this fraction in respect to autolysis is discussed.

The Impact of Antibacterial Peptides on Bacterial Lipid Membranes Depends on Stage of Growth

2020 ◽  
Author(s):  
Tzong-Hsien Lee ◽  
Vinzenz Hofferek ◽  
Marc-antoine Sani ◽  
Frances Separovic ◽  
Gavin Reid ◽  
...  
Keyword(s):  
Growth Phase ◽  
Lipid Membranes ◽  
Stationary Growth Phase ◽  
Exponential Growth Phase ◽  
Antibacterial Peptides ◽  
Stationary Growth ◽  
E Coli ◽  
Bacterial Lipid ◽  
Supported Lipid Membranes ◽  
The Impact

The impact of maculatin 1.1 (Mac1) on the mechanical properties of supported lipid membranes derived from exponential growth phase (EGP) and stationary growth phase (SGP) E. coli lipid extracts was...

scholarly journals Analysis of cell-growth-phase-related variations in hyaluronate synthase activity of isolated plasma-membrane fractions of cultured human skin fibroblasts

1986 ◽  
Vol 237 (2) ◽  
pp. 333-342 ◽  
Author(s):  
N Mian
Keyword(s):  
Plasma Membrane ◽  
Growth Phase ◽  
Plasma Membranes ◽  
Glucuronic Acid ◽  
Stationary Growth Phase ◽  
Binding Activity ◽  
Exponential Growth Phase ◽  
Human Skin Fibroblasts ◽  
Stationary Growth ◽  
Hyaluronate Synthase

Hyaluronate synthase activity is localized exclusively in plasma-membrane fractions of cultured human skin fibroblasts. The enzyme activity of plasma membranes prepared from exponential-growth-phase cells was about 6.5 times that of stationary-growth-phase cells. Hyaluronate synthase from exponential-growth-phase cells exhibited lower Km and higher Vmax. values for both UDP-N-acetylglucosamine and UDP-glucuronic acid and higher rate of elongation of hyaluronate chains compared with the enzyme from stationary-growth-phase cells. Hyaluronate synthase exhibited an extremely short half-life, 2.2 h and 3.8 h respectively when cells were treated with cycloheximide and actinomycin D. The cell-growth-phase-dependent variations in hyaluronate synthase activity appear to be due to its high turnover rate as well as due to some post-translational modification of the enzyme protein as cells progress from early exponential to stationary growth phase. The isolated plasma membranes contained a protein (Mr approx. 450,000) that was selectively autophosphorylated from [gamma-32P]ATP in vitro in the presence of hyaluronate precursors in the reaction mixture and that also exhibited some hyaluronate-synthesis-related properties. The 32P-labelled protein isolated from plasma membranes of exponentially growing cells expressed an efficient UDP-[14C]glucuronic acid- and UDP-N-acetyl[3H]glucosamine-binding activity and was able to synthesize oligosaccharides (Mr 5000) of [14C]glucuronic acid and N-acetyl[3H]glucosamine residues. The corresponding protein of stationary-growth-phase cells, which expressed much higher nucleotide-sugar-precursor-binding activity, appeared to have lost its oligosaccharide-synthesizing activity.

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