Optimisation of cell surface and structural components for improving adsorption capacity of Pseudomonas putida 5-x to Cu2+

2008 ◽  
Vol 34 (1/2/3/4) ◽  
pp. 285 ◽  
Author(s):  
G.H. Zheng ◽  
L. Wang ◽  
Q. Zhou ◽  
F.T. Li
Keyword(s):  
Cell Surface ◽  
Pseudomonas Putida ◽  
Adsorption Capacity ◽  
Structural Components

An optimal magnetite immobilized Pseudomonas- putida 5-x cellsystem for Cu2+ removal from industrial waste effluent

2000 ◽  
Vol 41 (12) ◽  
pp. 241-248 ◽  
Author(s):  
L. Wang ◽  
H. Chua ◽  
P. K. Wong ◽  
W. H. Lo ◽  
P. H. F. Yu ◽  
...  
Keyword(s):  
Cell Surface ◽  
Pseudomonas Putida ◽  
Adsorption Capacity ◽  
Growth Phase ◽  
Industrial Waste ◽  
Early Death ◽  
Freundlich Isotherm ◽  
Cell System ◽  
Desorption Process ◽  
Industrial Waste Effluent

An optimal magnetite immobilized Pseudomonas putida 5-x cell system was developed to remove Cu2+ from industrial waste effluent. Cu2+ adsorption capacity of P. putida 5-x cultured in sulphate-limiting medium (SLM) was minimum in early log growth phase, and reached maximum in late stationary growth phase or early death phase. Pretreated cells by 0.6 N HCl could greatly enhance the adsorption capacity of biomass up to 85.6 mg/g and had no significant effect for the loss of P. putida 5-x cells during the pretreatment. In a semi-continuous biosorption system, the removal efficiency of Cu2+ from wastewater reached 96%, and recovery efficiency of Cu2+ was 95%, and the concentration in the recovery solution was 1.4 g/L using 0.6 N HCl as eluant. The mechanism of Cu2+ adsorption by this type of biomass was studied by using the technique of transmission electron microscopy (TEM). Degradation of a peptidoglycan layer on the cell surface was observed after acidic pretreatment, but no further degradation appeared after the adsorption-desorption cycle. TEM and X-ray analysis also showed that Cu2+ was mainly accumulated on the cell surface, so it was effectively desorpted by acidic treatment in the desorption process. The process of adsorption obeyed the Freundlich isotherm.

scholarly journals Energetics and Surface Properties of Pseudomonas putida DOT-T1E in a Two-Phase Fermentation System with 1-Decanol as Second Phase

2006 ◽  
Vol 72 (6) ◽  
pp. 4232-4238 ◽  
Author(s):  
Grit Neumann ◽  
Sjef Cornelissen ◽  
Frank van Breukelen ◽  
Steffi Hunger ◽  
Holger Lippold ◽  
...  
Keyword(s):  
Cell Surface ◽  
Pseudomonas Putida ◽  
Surface Properties ◽  
Energy Charge ◽  
Growth Yield ◽  
Second Phase ◽  
Surface Charges ◽  
Two Phase ◽  
Presence And Absence ◽  
In Cells

ABSTRACT The solvent-tolerant strain Pseudomonas putida DOT-T1E was grown in batch fermentations in a 5-liter bioreactor in the presence and absence of 10% (vol/vol) of the organic solvent 1-decanol. The growth behavior and cellular energetics, such as the cellular ATP content and the energy charge, as well as the cell surface hydrophobicity and charge, were measured in cells growing in the presence and absence of 1-decanol. Although the cells growing in the presence of 1-decanol showed an about 10% reduced growth rate and a 48% reduced growth yield, no significant differences were measured either in the ATP and potassium contents or in the energy charge, indicating that the cells adapted completely at the levels of membrane permeability and energetics. Although the bacteria needed additional energy for adaptation to the presence of the solvent, they were able to maintain or activate electron transport phosphorylation, allowing homeostasis of the ATP level and energy charge in the presence of the solvent, at the price of a reduced growth yield. On the other hand, significantly enhanced cell hydrophobicities and more negative cell surface charges were observed in cells grown in the presence of 1-decanol. Both reactions occurred within about 10 min after the addition of the solvent and were significantly different after killing of the cells with toxic concentrations of HgCl2. This adaptation of the surface properties of the bacterium to the presence of solvents seems to be very similar to previously observed reactions on the level of lipopolysaccharides, with which bacteria adapt to environmental stresses, such as heat shock, antibiotics, or low oxygen content. The results give clear physiological indications that the process with P. putida DOT-T1E as the biocatalyst and 1-decanol as the solvent is a stable system for two-phase biotransformations that will allow the production of fine chemicals in economically sound amounts.

scholarly journals Membrane Vesicle Formation as a Multiple-Stress Response Mechanism Enhances Pseudomonas putida DOT-T1E Cell Surface Hydrophobicity and Biofilm Formation

2012 ◽  
Vol 78 (17) ◽  
pp. 6217-6224 ◽  
Author(s):  
Thomas Baumgarten ◽  
Stefanie Sperling ◽  
Jana Seifert ◽  
Martin von Bergen ◽  
Frank Steiniger ◽  
...  
Keyword(s):  
Stress Response ◽  
Cell Surface ◽  
Pseudomonas Putida ◽  
Biofilm Formation ◽  
Membrane Vesicle ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Outer Membrane Vesicles ◽  
Stress Factors ◽  
Content Type

ABSTRACTAmong the adaptive responses of bacteria to rapid changes in environmental conditions, those of the cell envelope are known to be the most crucial. Therefore, several mechanisms with which bacteria change their cell surface and membranes in the presence of different environmental stresses have been elucidated. Among these mechanisms, the release of outer membrane vesicles (MV) in Gram-negative bacteria has attracted particular research interest because of its involvement in pathogenic processes, such as that ofPseudomonas aeruginosabiofilm formation in cystic fibrosis lungs. In this study, we investigated the role of MV formation as an adaptive response ofPseudomonas putidaDOT-T1E to several environmental stress factors and correlated it to the formation of biofilms. In the presence of toxic concentrations of long-chain alcohols, under osmotic stress caused by NaCl, in the presence of EDTA, and after heat shock, cells of this strain released MV within 10 min in the presence of a stressor. The MV formed showed similar size and charge properties, as well as comparable compositions of proteins and fatty acids. MV release caused a significant increase in cell surface hydrophobicity, and an enhanced tendency to form biofilms was demonstrated in this study. Therefore, the release of MV as a stress response could be put in a physiological context.

scholarly journals Experimental Evolution of Pseudomonas putida under Silver Ion versus Nanoparticle Stress

2020 ◽  
Author(s):  
Feng Dong ◽  
Ana C. Quevedo ◽  
Xiang Wang ◽  
Eugenia Valsami-Jones ◽  
Jan-Ulrich Kreft
Keyword(s):  
Silver Nanoparticles ◽  
Cell Surface ◽  
Pseudomonas Putida ◽  
Experimental Evolution ◽  
Metal Binding ◽  
Metal Ion ◽  
Antibacterial Properties ◽  
Surface Proteins ◽  
Synonymous Mutations ◽  
Specific Effects

SummaryWhether the antibacterial properties of silver nanoparticles (AgNPs) are simply due to the release of silver ions (Ag+) or, additionally, nanoparticle-specific effects, has been debated for over a decade. We used experimental evolution of the model environmental bacterium Pseudomonas putida to ask whether bacteria respond differently to Ag+ or AgNP treatment. We pre-evolved five cultures of strain KT2440 for 70 d without Ag to reduce confounding adaptations before dividing the fittest pre-evolved culture into five cultures each, evolving in the presence of low concentrations of Ag+, well-defined AgNPs or Ag-free controls for a further 75 d. The mutations in the Ag+ or AgNP evolved populations displayed different patterns that were statistically significant. The non-synonymous mutations in AgNP-treated populations were mostly associated with cell surface proteins, including cytoskeletal membrane protein (FtsZ), membrane sensor and regulator (EnvZ and GacS) and periplasmic protein (PP_2758). In contrast, Ag+ treatment selected for mutations linked to cytoplasmic proteins, including metal ion transporter (TauB) and those with metal binding domains (ThiL and PP_2397). These results suggest the existence of AgNP-specific effects, either caused by sustained delivery of Ag+ from AgNP-dissolution, more proximate delivery from cell-surface bound AgNPs, or by direct AgNP action on the cell’s outer membrane.Originality-Significance StatementThe increasing use of silver nanoparticles (AgNPs) and their release into the environment may affect environmental microorganisms and their communities and evolution. It has long been debated whether the toxicity of AgNPs towards microorganisms is solely due to their dissolution into toxic Ag+ or whether distinct nanoparticle related toxicity exists. We set up an evolution experiment to explore the adaptation of the environmental model bacterium Pseudomonas putida to Ag+ versus AgNP stress in order to elucidate the potentially different toxicity mechanisms of ionic and nanoparticulate Ag. We found novel mutations and distinct mutation patterns under Ag+ and AgNP treatment by whole genome sequencing. Our work highlights the association of the mutations selected by Ag+ stress with metal ion metabolism inside the cells and the mutations specific to AgNP stress with the cell’s surface. The finding that P. putida cells evolved in different directions under selection by Ag+ and AgNPs demonstrates a need for assessing the toxicity of nanomaterials separately in any environmental risk assessments.

Characterization of cell surface properties in agglutinable and nonagglutinable mutants of Pseudomonas putida

1993 ◽  
Vol 39 (8) ◽  
pp. 787-794 ◽  
Author(s):  
C. R. Buell ◽  
R. Whetton ◽  
P. Tari ◽  
A. J. Anderson
Keyword(s):  
Molecular Weight ◽  
Cell Surface ◽  
Pseudomonas Putida ◽  
Outer Membrane ◽  
Cell Envelope ◽  
Surface Glycoprotein ◽  
Chemical Mutagenesis ◽  
Wild Type ◽  
Surface Binding ◽  
Surface Features

Cells of an aggressive, root-colonizing isolate of Pseudomonas putida are agglutinated by a root surface glycoprotein. The agglutination phenotype in P. putida isolate Corvallis is lacking in mutants (Agg−) derived by Tn5 insertion and chemical mutagenesis. Specific mutation in the aggA locus by Tn5 insertion results in loss of agglutinability that is complemented in trans by a wild-type copy of the P. putida aggA locus. We examined the biochemical bases of agglutination in P. putida by comparing cell surface features in Agg+, Agg− mutants, and a genetically restored aggA mutant. No changes in gross cell surface features involving hydrophobic or hydrophilic binding or net negative charge were observed. Three macromolecular features, pili, flagella, and lipopolysaccharide size, did not differ between Agg+ and Agg− mutants. Protein profiles of cell envelope, periplasmic, and outer membrane preparations revealed pleiotropic effects of mutation in agglutination phenotype including alterations of an outer membrane protein of 47 000 molecular weight and periplasmic proteins of 56 000 and 60 000 molecular weight. The protein alterations seen in the aggA::Tn5 Agg− mutant 5123 reverted to wild-type patterns upon introduction of a wild-type copy of the aggA locus. These data suggest agglutinability may be conditioned by more than one proteinaceous component associated with the bacterial envelope layers.Key words: cell surface, binding, recognition.

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