The role of catalase isozymes in the culturability of the root colonizer Pseudomonas putida after exposure to hydrogen peroxide and antibiotics

1994 ◽  
Vol 40 (5) ◽  
pp. 382-387 ◽  
Author(s):  
Martin G. Klotz ◽  
Anne J. Anderson
Keyword(s):  
Hydrogen Peroxide ◽  
Stationary Phase ◽  
Pseudomonas Putida ◽  
Growth Phase ◽  
Stationary Growth Phase ◽  
Exponential Phase ◽  
Wild Type ◽  
Early Stationary Growth Phase ◽  
Mutant Cells

The culturability of Pseudomonas putida cells after exposure to hydrogen peroxide and antibiotics was correlated with growth-dependent expression of catalase isozymes. Exponential phase wild-type cells, which contained catalase isozyme A, survived a 15-min treatment with less than 4 mM hydrogen peroxide, but were killed by higher concentrations. The culturability of P. putida mutant JIM, which lacked any functional catalase in exponential phase, was reduced by more than 75% after a 15-min exposure to ≥ 0.25 mM hydrogen peroxide. Because submillimolar concentrations of hydrogen peroxide are physiologically relevant in the bacterial cell, our results demonstrate that catalase isozyme A has essential housekeeping functions for growing cultures of P. putida. The accumulation of catalase isozymes B and C during growth into stationary phase coincided with a decrease in the sensitivity of wild-type and JIM cells of P. putida to hydrogen peroxide. Late stationary phase wild-type cells survived a 15-min exposure to even 50 mM hydrogen peroxide and mutant J1M cells survived exposure to 20 mM but not 50 mM hydrogen peroxide. The antibiotics tetracycline and kanamycin, which inhibit protein synthesis, were used to study the role of catalase induction in resistance to hydrogen peroxide. More than 40 and 80% of exponential phase cells of P. putida wild-type and J1M strains, respectively, were rendered nonculturable after a 20-min exposure to 45 μM tetracycline. Surprisingly, stationary phase cells of both P. putida strains were culturable after a 20-min exposure to tetracycline but remained sensitive to kanamycin. Exposure to tetracycline of stationary phase cells did not reduce the resistance of these cells to hydrogen peroxide. Tetracycline but not kanamycin increased the activity of catalase in lysates prepared from P. putida wild-type and mutant cells in early stationary growth phase. At this growth phase, only catalase isozyme B is operational in both strains, which suggests that tetracycline affects the activity of this enzyme.Key words: Pseudomonas putida, antibiotics, catalase, culturability, growth phase.

Characterization of catalase activities in a root-colonizing isolate of Pseudomonas putida

1992 ◽  
Vol 38 (10) ◽  
pp. 1026-1032 ◽  
Author(s):  
J. Katsuwon ◽  
A. J. Anderson
Keyword(s):  
Stationary Phase ◽  
Pseudomonas Putida ◽  
Growth Phase ◽  
Specific Activity ◽  
Active Oxygen Species ◽  
Stationary Growth Phase ◽  
Wild Type ◽  
Ph Optimum ◽  
Chloroform Methanol ◽  
Root Surfaces

Pseudomonas putida, a saprophytic root-colonizing bacterium, produces multiple forms of catalase. Catalase A, which increases in specific activity during growth phase and after treatment with H2O2, is located in the cytoplasm and is inhibited by 3-amino-1,2,4-triazole, EDTA, and cyanide, but not by chloroform–methanol treatment. Catalase B, which is induced by external H2O2 or during stationary phase of growth, is membrane associated and is inhibited by chloroform–methanol, EDTA, and cyanide, but not by aminotriazole. Catalase A has a broad pH optimum, from pH 6.0 to 11.0, with two peaks, at pH 8.0 and 11.0. Catalase B is most active at pH 5.0–11.0. Mutant J-1, generated by ethyl methanesulfonate mutagenesis, lacked catalase A activity in extracts of cells harvested throughout lag to early stationary growth phase in liquid medium. Catalase B was produced by J-1 in stationary phase. Exposure of J-1 to H2O2 caused the production of both catalase A and catalase B. Mutant J-1 was more susceptible to cell death than the wild type upon direct exposure to 2.5 mM H2O2 but survived this treatment after exposure to lower (0.3 mM), nonlethal doses of H2O2. The ability to adapt to H2O2 may be related to the behaviour of J-1 on roots where active oxygen species are produced by root surface enzymes. J-1 colonized root surfaces at wild-type levels and produced catalases A and B after exposure to root surfaces for 12 h. Key words: Pseudomonas putida, catalase, root colonization.

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 AmiC Functions as an N-Acetylmuramyl-l-Alanine Amidase Necessaryfor Cell Separation and Can Promote Autolysis in Neisseria gonorrhoeae

2006 ◽  
Vol 188 (20) ◽  
pp. 7211-7221 ◽  
Author(s):  
Daniel L. Garcia ◽  
Joseph P. Dillard
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Stationary Phase ◽  
Growth Characteristics ◽  
Wild Type ◽  
Cell Components ◽  
Section Electron ◽  
Cell Wall Breakdown ◽  
Mutant Cells

ABSTRACT Neisseria gonorrhoeae is prone to undergo autolysis under many conditions not conducive to growth. The role of autolysis during gonococcal infection is not known, but possible advantages for the bacterial population include provision of nutrients to a starving population, modulation of the host immune response by released cell components, and donation of DNA for natural transformation. Biochemical studies indicated that an N-acetylmuramyl-l-alanine amidase is responsible for cell wall breakdown during autolysis. In order to better understand autolysis and in hopes of creating a nonautolytic mutant, we mutated amiC, the gene for a putative peptidoglycan-degrading amidase in N. gonorrhoeae. Characterization of peptidoglycan fragments released during growth showed that an amiC mutant did not produce free disaccharide, consistent with a role for AmiC as an N-acetylmuramyl-l-alanine amidase. Compared to the wild-type parent, the mutant exhibited altered growth characteristics, including slowed exponential-phase growth, increased turbidity in stationary phase, and increased colony opacity. Thin-section electron micrographs showed that mutant cells did not fully separate but grew as clumps. Complementation of the amiC deletion mutant with wild-type amiC restored wild-type growth characteristics and transparent colony morphology. Overexpression of amiC resulted in increased cell lysis, supporting AmiC's purported function as a gonococcal autolysin. However, amiC mutants still underwent autolysis in stationary phase, indicating that other gonococcal enzymes are also involved in this process.

scholarly journals Proteome-Wide Analysis of Trypanosoma cruzi Exponential and Stationary Growth Phases Reveals a Subcellular Compartment-Specific Regulation

Genes ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 413 ◽  
Author(s):  
Carla Avila ◽  
Simon Mule ◽  
Livia Rosa-Fernandes ◽  
Rosa Viner ◽  
María Barisón ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Stationary Phase ◽  
Growth Phase ◽  
Ribosomal Proteins ◽  
Stationary Growth Phase ◽  
Exponential Phase ◽  
Insect Vector ◽  
Growth Phases ◽  
Stationary Growth ◽  
Subcellular Compartment

Trypanosoma cruzi, the etiologic agent of Chagas disease, cycles through different life stages characterized by defined molecular traits associated with the proliferative or differentiation state. In particular, T. cruzi epimastigotes are the replicative forms that colonize the intestine of the Triatomine insect vector before entering the stationary phase that is crucial for differentiation into metacyclic trypomastigotes, which are the infective forms of mammalian hosts. The transition from proliferative exponential phase to quiescent stationary phase represents an important step that recapitulates the early molecular events of metacyclogenesis, opening new possibilities for understanding this process. In this study, we report a quantitative shotgun proteomic analysis of the T. cruzi epimastigote in the exponential and stationary growth phases. More than 3000 proteins were detected and quantified, highlighting the regulation of proteins involved in different subcellular compartments. Ribosomal proteins were upregulated in the exponential phase, supporting the higher replication rate of this growth phase. Autophagy-related proteins were upregulated in the stationary growth phase, indicating the onset of the metacyclogenesis process. Moreover, this study reports the regulation of N-terminally acetylated proteins during growth phase transitioning, adding a new layer of regulation to this process. Taken together, this study reports a proteome-wide rewiring during T. cruzi transit from the replicative exponential phase to the stationary growth phase, which is the preparatory phase for differentiation.

scholarly journals Role of the Multidrug Resistance Regulator MarA in Global Regulation of the hdeAB Acid Resistance Operon in Escherichia coli

2007 ◽  
Vol 190 (4) ◽  
pp. 1290-1297 ◽  
Author(s):  
Cristian Ruiz ◽  
Laura M. McMurry ◽  
Stuart B. Levy
Keyword(s):  
Escherichia Coli ◽  
Stationary Phase ◽  
Indirect Effects ◽  
Acid Resistance ◽  
Transcriptional Regulator ◽  
Exponential Phase ◽  
Direct And Indirect Effects ◽  
Multiple Antibiotic Resistance ◽  
Wild Type

ABSTRACT MarA, a transcriptional regulator in Escherichia coli, affects functions such as multiple-antibiotic resistance (Mar) and virulence. Usually an activator, MarA is a repressor of hdeAB and other acid resistance genes. We found that, in wild-type cells grown in LB medium at pH 7.0 or pH 5.5, repression of hdeAB by MarA occurred only in stationary phase and was reduced in the absence of H-NS and GadE, the main regulators of hdeAB. Moreover, repression of hdeAB by MarA was greater in the absence of GadX or Lrp in exponential phase at pH 7.0 and in the absence of GadW or RpoS in stationary phase at pH 5.5. In turn, MarA enhanced repression of hdeAB by H-NS and hindered activation by GadE in stationary phase and also reduced the activity of GadX, GadW, RpoS, and Lrp on hdeAB under some conditions. As a result of its direct and indirect effects, overexpression of MarA prevented most of the induction of hdeAB expression as cells entered stationary phase and made the cells sevenfold more sensitive to acid challenge at pH 2.5. These findings show that repression of hdeAB by MarA depends on pH, growth phase, and other regulators of hdeAB and is associated with reduced resistance to acid conditions.

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 Effects of Combination of Different −10 Hexamers and Downstream Sequences on Stationary-Phase-Specific Sigma Factor ςS-Dependent Transcription in Pseudomonas putida

2000 ◽  
Vol 182 (23) ◽  
pp. 6707-6713 ◽  
Author(s):  
Eve-Ly Ojangu ◽  
Andres Tover ◽  
Riho Teras ◽  
Maia Kivisaar
Keyword(s):  
Stationary Phase ◽  
Pseudomonas Putida ◽  
Sigma Factor ◽  
Sigma Factors ◽  
Deficient Mutant ◽  
Wild Type ◽  
In Vivo Experiments ◽  
Silent Genes ◽  
Rna Polymerase Holoenzyme

ABSTRACT The main sigma factor activating gene expression, necessary in stationary phase and under stress conditions, is ςS. In contrast to other minor sigma factors, RNA polymerase holoenzyme containing ςS (EςS) recognizes a number of promoters which are also recognized by that containing ς70 (Eς70). We have previously shown that transposon Tn4652 can activate silent genes in starvingPseudomonas putida cells by creating fusion promoters during transposition. The sequence of the fusion promoters is similar to the ς70-specific promoter consensus. The −10 hexameric sequence and the sequence downstream from the −10 element differ among these promoters. We found that transcription from the fusion promoters is stationary phase specific. Based on in vivo experiments carried out with wild-type and rpoS-deficient mutant P. putida, the effect of ςS on transcription from the fusion promoters was established only in some of these promoters. The importance of the sequence of the −10 hexamer has been pointed out in several published papers, but there is no information about whether the sequences downstream from the −10 element can affect ςS-dependent transcription. Combination of the −10 hexameric sequences and downstream sequences of different fusion promoters revealed that ςS-specific transcription from these promoters is not determined by the −10 hexameric sequence only. The results obtained in this study indicate that the sequence of the −10 element influences ςS-specific transcription in concert with the sequence downstream from the −10 box.

scholarly journals Growth Phase Regulation of flaA Expression in Helicobacter pylori Is luxS Dependent

2004 ◽  
Vol 72 (9) ◽  
pp. 5506-5510 ◽  
Author(s):  
John T. Loh ◽  
Mark H. Forsyth ◽  
Timothy L. Cover
Keyword(s):  
Helicobacter Pylori ◽  
Growth Phase ◽  
Wild Type ◽  
Phase Dependence ◽  
Autoinducer 2 ◽  
Extracellular Signaling ◽  
Reporter Strains ◽  
Phase Regulation ◽  
H Pylori

ABSTRACT LuxS plays a role in the synthesis of an extracellular signaling molecule, autoinducer 2 (AI-2). To analyze a possible role of AI-2 in regulating Helicobacter pylori gene expression, we constructed a panel of transcriptional reporter strains. We show that the expression of H. pylori flaA is growth phase dependent and that flaA transcription increases in association with increased culture density. Mutating the luxS gene eliminates growth-phase-dependent control of flaA, and this growth phase dependence is restored when the luxS mutant strain is complemented with the wild-type luxS gene.

LuxS modulates motility and secretion of extracellular protease in fish pathogen Vibrio harveyi

2021 ◽  
Author(s):  
yaqiu Zhang ◽  
Yiqing Deng ◽  
Juan Feng ◽  
Jianmei Hu ◽  
Haoxiang Chen ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Stationary Growth Phase ◽  
Extracellular Protease ◽  
Fish Pathogen ◽  
Wild Type ◽  
Stationary Growth ◽  
Qrt Pcr ◽  
Reverse Transcription Pcr ◽  
Luxs Mutant

In this study, an in-frame deletion of the luxS gene was constructed to reveal the role of LuxS in the physiology and virulence of V. harveyi. The statistical analysis showed no significant differences in the growth ability, biofilm formation, antibiotic susceptibility, virulence by intraperitoneal injection, and the ability of V. harveyi to colonize the spleen and liver of the pearl gentian grouper between the wild-type (WT) and the luxS mutant. However, the deletion of luxS decreased the secretion of extracellular protease, while increased the ability of swimming and swarming. Simultaneously, a luxS-deleted mutant showed overproduction of lateral flagella, and an intact luxS complemented the defect. Since motility is flagella dependent, 16 of V. harveyi flagella biogenesis related genes were selected for further analysis. Based on quantitative real-time reverse transcription-PCR (qRT-PCR), the expression levels of these genes, including the polar flagella genes flaB, flhA, flhF, flhB, flhF, fliS, and flrA and the lateral flagella genes flgA, flgB, fliE, fliF, lafA, lafK, and motY, were significantly up-regulated in the ΔluxS: pMMB207 (ΔluxS+) strain as compared with the V. harveyi 345: pMMB207 (WT+) and C-ΔluxS strains during the early, mid-exponential, and stationary growth phase.

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