Novel components of Pseudomonas putida biofilm exopolymeric matrix and a transcriptome analysis of the effects of osmotic and matric stress

2010 ◽  
Author(s):  
Lindsey Nielsen
2007 ◽  
Vol 190 (1) ◽  
pp. 416-420 ◽  
Author(s):  
Ana B. Hervás ◽  
Inés Canosa ◽  
Eduardo Santero

ABSTRACT This work describes a regulatory network of Pseudomonas putida controlled in response to nitrogen availability. We define NtrC as the master nitrogen regulator and suggest that it not only activates pathways for the assimilation of alternative nitrogen sources but also represses carbon catabolism under nitrogen-limited conditions, possibly to prevent excessive carbon and energy flow in the cell.


Microbiology ◽  
2018 ◽  
Vol 164 (6) ◽  
pp. 883-888 ◽  
Author(s):  
Nanna B. Svenningsen ◽  
Esteban Martínez-García ◽  
Mette H. Nicolaisen ◽  
Victor de Lorenzo ◽  
Ole Nybroe

2007 ◽  
Vol 190 (8) ◽  
pp. 2822-2830 ◽  
Author(s):  
Nick J. P. Wierckx ◽  
Hendrik Ballerstedt ◽  
Jan A. M. de Bont ◽  
Johannes H. de Winde ◽  
Harald J. Ruijssenaars ◽  
...  

ABSTRACT The unknown genetic basis for improved phenol production by a recombinant Pseudomonas putida S12 derivative bearing the tpl (tyrosine-phenol lyase) gene was investigated via comparative transcriptomics, nucleotide sequence analysis, and targeted gene disruption. We show upregulation of tyrosine biosynthetic genes and possibly decreased biosynthesis of tryptophan caused by a mutation in the trpE gene as the genetic basis for the enhanced phenol production. In addition, several genes in degradation routes connected to the tyrosine biosynthetic pathway were upregulated. This either may be a side effect that negatively affects phenol production or may point to intracellular accumulation of tyrosine or its intermediates. A number of genes identified by the transcriptome analysis were selected for targeted disruption in P. putida S12TPL3. Physiological and biochemical examination of P. putida S12TPL3 and these mutants led to the conclusion that the metabolic flux toward tyrosine in P. putida S12TPL3 was improved to such an extent that the heterologous tyrosine-phenol lyase enzyme had become the rate-limiting step in phenol biosynthesis.


Biofilms ◽  
2004 ◽  
Vol 1 (4) ◽  
pp. 361-368 ◽  
Author(s):  
M. van de Mortel ◽  
W.-S. Chang ◽  
L. J. Halverson

The desiccation tolerance of Pseudomonas putida strain mt-2 cells within intact unsaturated biofilms and cells cultivated in liquid media was examined. Since as soils dry there can be an increase in the solute potential and reductions in nutrient availability, we also assessed the effect of the solute and matric (low-water-content) components of the total water potential, and nutrient availability on cell survival. Biofilms were cultivated in model laboratory systems that can simulate the matric and solute components of the total water potential and the poorly mixed nature of unsaturated habitats. Desiccation stress was imposed by exposing biofilm and planktonic cells to environments with controlled relative humidities. Our results show that biofilm cells are more tolerant to air drying than are planktonic cells, and tolerance is enhanced when there is an adequate supply of nutrients available to the cells. We provide evidence suggesting that a major factor contributing to desiccation sensitivity is the matric stress itself rather than solute stress and that matric stress is inherently more stressful to P. putida than is the thermodynamically equivalent solute stress.


2015 ◽  
Vol 15 (1) ◽  
Author(s):  
Nanna B. Svenningsen ◽  
Danilo Pérez-Pantoja ◽  
Pablo I. Nikel ◽  
Mette H. Nicolaisen ◽  
Víctor de Lorenzo ◽  
...  

2003 ◽  
Vol 185 (20) ◽  
pp. 6199-6204 ◽  
Author(s):  
Woo-Suk Chang ◽  
Larry J. Halverson

ABSTRACT Pseudomonas putida strain mt-2 unsaturated biofilm formation proceeds through three distinct developmental phases, culminating in the formation of a microcolony. The form and severity of reduced water availability alter cell morphology, which influences microcolony size and ultrastructure. The dehydration (matric stress) treatments resulted in biofilms comprised of smaller cells, but they were taller and more porous and had a thicker extracellular polysaccharide layer at the air interface. In the solute stress treatments, cell filamentation occurred more frequently in the presence of high concentrations of ionic (but not nonionic) solutes, and these filamented cells drastically altered the biofilm architecture.


2009 ◽  
Vol 221 (03) ◽  
Author(s):  
GHS Richter ◽  
UE Hattenhorst ◽  
B Beinvogl ◽  
D Schenk ◽  
MS Staege ◽  
...  

2012 ◽  
Vol 33 (S 01) ◽  
Author(s):  
K Becker ◽  
A Klein ◽  
OA Wrulich ◽  
P Gruber ◽  
D Fuchs ◽  
...  

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