scholarly journals Analysis of Dibenzothiophene Desulfurization in a Recombinant Pseudomonas putida Strain

2008 ◽  
Vol 75 (3) ◽  
pp. 875-877 ◽  
Author(s):  
Javier Calzada ◽  
Mar�a T. Zamarro ◽  
Almudena Alc�n ◽  
Victoria E. Santos ◽  
Eduardo D�az ◽  
...  
Keyword(s):  
Pseudomonas Putida ◽  
Exponential Growth ◽  
Exponential Phase ◽  
Cell Process ◽  
Growth Phases ◽  
Early Exponential Phase ◽  
Sharp Maximum ◽  
Resting Cell

ABSTRACT Biodesulfurization was monitored in a recombinant Pseudomonas putida CECT5279 strain. DszB desulfinase activity reached a sharp maximum at the early exponential phase, but it rapidly decreased at later growth phases. A model two-step resting-cell process combining sequentially P. putida cells from the late and early exponential growth phases was designed to significantly increase biodesulfurization.

scholarly journals Post-translational regulation of the RpoS and PsrA genes in pseudomonas putida WCS358: The role of ClpXP protease

2008 ◽  
Vol 60 (1) ◽  
pp. 1-4
Author(s):  
B. Jovcic ◽  
Jelena Begovic ◽  
Jelena Lozo ◽  
Lj. Topisirovic ◽  
M. Kojic
Keyword(s):  
Western Blot ◽  
Pseudomonas Putida ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Translational Regulation ◽  
Stationary Phases ◽  
Transcriptional Regulators ◽  
Exponential Phase ◽  
Early Exponential Phase

The RpoS and PsrA proteins are key transcriptional regulators that are activated in response to the stationary phase of growth in pseudomonads. This study was designed to establish whether ClpXP (ATP-dependent serine protease) regulates levels of RpoS and PsrA in Pseudomonas putida WCS358. Western blot analysis of P. putida WCS358 protein extracts from the early exponentianl, late exponential, and stationary phases of growth with antibodies against RpoS and PsrA revealed that these proteins are degraded by ClpXP in the early exponential phase of growth. The obtained results demonstrate a role for ClpXP protease in post-translational regulation of proteins encoded by the rpoS and psrA genes in Pseudomonas spp.

scholarly journals Casein Utilization by Streptococcus thermophilus Results in a Diauxic Growth in Milk

2002 ◽  
Vol 68 (6) ◽  
pp. 3162-3165 ◽  
Author(s):  
Catherine Letort ◽  
Michèle Nardi ◽  
Peggy Garault ◽  
Véronique Monnet ◽  
Vincent Juillard
Keyword(s):  
Amino Acids ◽  
Growth Rate ◽  
Exponential Growth ◽  
Streptococcus Thermophilus ◽  
Exponential Phase ◽  
Peptide Transport ◽  
Diauxic Growth ◽  
Transport Activity ◽  
Growth Phases

ABSTRACT In milk, Streptococcus thermophilus displays two distinct exponential growth phases, separated by a nonexponential one, during which proteinase synthesis was initiated. During the second exponential phase, utilization of caseins as the source of amino acids resulted in a decrease in growth rate, presumably caused by a limiting peptide transport activity.

Effect of EDTA on Salmonella enterica serovar Typhimurium involves a component not assignable to lipopolysaccharide release

Microbiology ◽  
2003 ◽  
Vol 149 (8) ◽  
pp. 2015-2021 ◽  
Author(s):  
H.-L. Alakomi ◽  
M. Saarela ◽  
I. M. Helander
Keyword(s):  
Fatty Acids ◽  
Growth Curve ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Exponential Phase ◽  
Growth Phases ◽  
Late Exponential Phase ◽  
Early Exponential Phase ◽  
Serovar Typhimurium ◽  
Hydrophobic Probe

The effect of EDTA on Salmonella enterica serovar Typhimurium was studied in different growth phases with cells grown with or without Ca2+ and Mg2+ supplementation. EDTA affected the outer membrane much more strongly in the early exponential phase than in the mid- or late exponential phase, as indicated by uptake of 1-N-phenylnaphthylamine (a nonpolar hydrophobic probe, M r 219), and detergent (SDS) susceptibility. This effect was, however, not paralleled by LPS release (determined by measuring LPS-specific fatty acids or 14C-labelled LPS in cell-free supernatants, per a standardized cell density), which remained unchanged as a function of the growth curve. The conclusion from these results is that in the early exponential phase the effect of EDTA in S. enterica involves a component that is independent of LPS release.

scholarly journals H-NS Represses Salmonella enterica Serovar Typhimurium dsbA Expression during Exponential Growth

2004 ◽  
Vol 186 (4) ◽  
pp. 910-918 ◽  
Author(s):  
C. V. Gallant ◽  
T. Ponnampalam ◽  
H. Spencer ◽  
J. C. D. Hinton ◽  
N. L. Martin
Keyword(s):  
Exponential Growth ◽  
Salmonella Enterica ◽  
Immunoblot Analysis ◽  
Exponential Phase ◽  
Exponential Growth Phase ◽  
Mobility Shift ◽  
Altered Expression ◽  
Serovar Typhimurium ◽  
In The Wild ◽  
Maximal Expression

ABSTRACT Disulfide bond formation catalyzed by disulfide oxidoreductases occurs in the periplasm and plays a major role in the proper folding and integrity of many proteins. In this study, we were interested in elucidating factors that influence the regulation of dsbA, a gene coding for the primary disulfide oxidoreductase found in Salmonella enterica serovar Typhimurium. Strains with mutations created by transposon mutagenesis were screened for strains with altered expression of dsbA. A mutant (NLM2173) was found where maximal expression of a dsbA::lacZ transcriptional fusion occurred in the exponential growth phase in contrast to that observed in the wild type where maximal expression occurs in stationary phase. Sequence analysis of NLM2173 demonstrated that the transposon had inserted upstream of the gene encoding H-NS. Western immunoblot analysis using H-NS and StpA antibodies showed decreased amounts of H-NS protein in NLM2173, and this reduction in H-NS correlated with an increase of StpA protein. Northern blot analysis with a dsbA-specific probe showed an increase in dsbA transcript during exponential phase of growth. Direct binding of H-NS to the dsbA promoter region was verified using purified H-NS in electrophoretic mobility shift assays. Thus, a reduction in H-NS protein is correlated with a derepression of dsbA in NLM2173, suggesting that H-NS normally plays a role in suppressing the expression of dsbA during exponential phase growth.

A Wake-Up Call for the Efficient Use of the Bacterial Resting Cell Process, with Focus on Low Solubility Products

2020 ◽  
Vol 77 (8) ◽  
pp. 1349-1362 ◽  
Author(s):  
Esther Moens ◽  
Selin Bolca ◽  
Sam Possemiers ◽  
Willy Verstraete
Keyword(s):  
Cell Process ◽  
Resting Cell ◽  
Solubility Products ◽  
Low Solubility

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.

Sign in / Sign up

Export Citation Format

Share Document