Binding of Pu(IV) to galacturonic acid and extracellular polymeric substances (EPS) from Shewanella putrefaciens, Clostridium sp. and Pseudomonas fluorescens

2008 ◽  
Vol 96 (9-11) ◽  
Author(s):  
Ruth M. Harper ◽  
Cetin Kantar ◽  
Bruce D. Honeyman
Keyword(s):  
Pseudomonas Fluorescens ◽  
Galacturonic Acid ◽  
Extracellular Polymeric Substances ◽  
Shewanella Putrefaciens

scholarly journals The role of hydrodynamic stress on the phenotypic characteristics of single and binary biofilms of Pseudomonas fluorescens

2007 ◽  
Vol 55 (8-9) ◽  
pp. 437-445 ◽  
Author(s):  
M. Simões ◽  
M.O. Pereira ◽  
M.J. Vieira
Keyword(s):  
Pseudomonas Fluorescens ◽  
Type Strain ◽  
Extracellular Polymeric Substances ◽  
Structural Characteristics ◽  
Outer Membrane Proteins ◽  
Processing Plant ◽  
Industrial Processing ◽  
Cellular Density ◽  
Biofilm Development

This study investigates the phenotype of turbulent (Re = 5,200) and laminar (Re = 2,000) flow-generated Pseudomonas fluorescens biofilms. Three P. fluorescens strains, the type strain ATCC 13525 and two strains isolated from an industrial processing plant, D3-348 and D3-350, were used throughout this study. The isolated strains were used to form single and binary biofilms. The biofilm physiology (metabolic activity, cellular density, mass, extracellular polymeric substances, structural characteristics and outer membrane proteins [OMP] expression) was compared. The results indicate that, for every situation, turbulent flow-generated biofilms were more active (p<0.05), had more mass per cm2 (p<0.05), a higher cellular density (p<0.05), distinct morphology, similar matrix proteins (p>0.1) and identical (isolated strains – single and binary biofilms) and higher (type strain) matrix polysaccharides contents (p<0.05) than laminar flow-generated biofilms. Flow-generated biofilms formed by the type strain revealed a considerably higher cellular density and amount of matrix polysaccharides than single and binary biofilms formed by the isolated strains (p<0.05). Similar OMP expression was detected for the several single strains and for the binary situation, not dependent on the hydrodynamic conditions. Binary biofilms revealed an equal coexistence of the isolated strains with apparent neutral interactions. In summary, the biofilms formed by the type strain represent, apparently, the worst situation in a context of control. The results obtained clearly illustrate the importance of considering strain variation and hydrodynamics in biofilm development, and complement previous studies which have focused on physical aspects of structural and density differences.

scholarly journals Denitrification performance of Pseudomonas fluorescens Z03 immobilized by graphene oxide-modified polyvinyl-alcohol and sodium alginate gel beads at low temperature

2020 ◽  
Vol 7 (3) ◽  
pp. 191542 ◽  
Author(s):  
Meizhen Tang ◽  
Jie Jiang ◽  
Qilin Lv ◽  
Bin Yang ◽  
Mingna Zheng ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Low Temperature ◽  
Polyvinyl Alcohol ◽  
Pseudomonas Fluorescens ◽  
Sodium Alginate ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Extracellular Polymeric Substances ◽  
Aerobic Denitrification ◽  
Gel Beads

Improving the effect of microbial denitrification under low-temperature conditions has been a popular focus of research in recent years. In this study, graphene oxide (GO)-modified polyvinyl-alcohol (PVA) and sodium alginate (SA) (GO/PVA–SA) gel beads were used as a heterotrophic nitrification–aerobic denitrification (HN–AD) bacteria ( Pseudomonas fluorescens Z03) carrier to enhance nitrogen removal efficiency levels at low temperatures (6–8°C). The removal efficiency of N H 4     + -N and N O 3       − -N and the variations in concentrations of extracellular polymeric substances (EPS) under different GO doses (0.03–0.15 g l −1 ) were studied. The results indicated that the addition of GO can improve the efficiency of nitrogen removal, and the highest removal efficiency level and highest carbohydrate, protein, and total EPS content levels (50.28 mg, 132.78 mg and 183.06 mg (g GO/PVA–SA gel) −1 , respectively) were obtained with 0.15 g l −1 GO. The simplified Monod model accurately predicted the nitrogen removal efficiency level. These findings suggested that the application of GO serves as an effective means to enhance nitrogen removal by stimulating the activity of HN–AD bacteria.

scholarly journals Elucidating Antibacterial Activity and Mechanism of Daphnetin against Pseudomonas fluorescens and Shewanella putrefaciens

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Wenru Liu ◽  
Jun Mei ◽  
Jing Xie
Keyword(s):  
Antibacterial Activity ◽  
Electron Microscope ◽  
Cell Membrane ◽  
Pseudomonas Fluorescens ◽  
Antibacterial Effect ◽  
Shewanella Putrefaciens ◽  
Ultrastructural Changes ◽  
Natural Food ◽  
Bacterial Cells ◽  
Viability Analysis

In this research, the antibacterial activity and mechanism of daphnetin against Pseudomonas fluorescens and Shewanella putrefaciens were evaluated. The minimum inhibitory concentration (MIC) of daphnetin on P. fluorescens and S. putrefaciens was 0.16 and 0.08 mg·mL−1, respectively. The growth curve test also showed that daphnetin had a good antibacterial effect. The results of intracellular component leakage and cell viability analysis illustrated that daphnetin destroyed the morphology of the cell membrane. According to scanning electron microscope and transmission electron microscope observations, the treated bacterial cells displayed obvious morphological and ultrastructural changes in the cell membrane of the two tested strains, whichconfirmed daphnetin’s damage to the integrity of the cell membrane. The findings indicated that daphnetin mainly exerted its antibacterial effect by destroying the membrane and suggested that it had good potential to be as a natural food preservative.

Effects of extracellular polymeric substances of Pseudomonas fluorescens, citrate, and oxalate on Pb sorption by an acidic Ultisol

2019 ◽  
Vol 171 ◽  
pp. 790-797 ◽  
Author(s):  
Jackson Nkoh Nkoh ◽  
Hai-lung Lu ◽  
Xiao-ying Pan ◽  
Ge Dong ◽  
Muhammad Aqeel Kamran ◽  
...  
Keyword(s):  
Pseudomonas Fluorescens ◽  
Extracellular Polymeric Substances

Identification of the effect of extracellular polymeric substances on bacterial adhesion to the membrane surface in a membrane bioreactor using Pseudomonas fluorescens

2007 ◽  
Vol 55 (1-2) ◽  
pp. 35-42 ◽  
Author(s):  
Y. Yeo ◽  
N. Jang ◽  
J. Cho ◽  
K.-S. Kim ◽  
I.S. Kim
Keyword(s):  
Pseudomonas Fluorescens ◽  
Membrane Fouling ◽  
Bacterial Adhesion ◽  
Membrane Bioreactor ◽  
Extracellular Polymeric Substances ◽  
Municipal Wastewater ◽  
Membrane Surface ◽  
Municipal Wastewater Treatment ◽  
Wastewater Treatment Process ◽  
Specific Cake Resistance

In a membrane bioreactor (MBR) process containing a variety of bacteria, the bacterial adhesion to the membrane surface, prior to cake formation, causes an increased filtration resistance. In this study, Pseudomonas fluorescens, commonly found in the municipal wastewater treatment process with activated sludge, was used to show the effects of extracellular polymeric substances (EPS) on bacterial adhesion to the membrane surface in the MBR. Of the various roles of EPS in promoting membrane fouling, the adhesion of bacteria to the membrane surface was calculated using the specific cake resistance (α, m/kg). Although the amount of EPS binding with bacteria was increased by the addition of Ca2 + , there was no significant effect on the bacterial growth. The results of the particle size distribution showed that the addition of Ca2 +  increased flocculation, allowing the formation of a complex with the bacteria and EPS. In order to identify the effects of the addition of Ca2 +  on the hydrophobicity, the contact angle was also measured. The result showed that the addition of Ca2 +  showed no significant differences in the hydrophobicity, even though there was an increase in flocculation. With the bacteria containing a higher EPS concentration, a higher specific cake resistance was observed. From the results of the adhesion experiment, which was conducted with various EPS levels, displayed as the COD and TOC concentration, an increased EPS concentration was shown to promote bacterial adhesion to the membrane surface.

scholarly journals Microbiologically influenced corrosion inhibition of carbon steel via biomineralization induced by Shewanella putrefaciens

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Yuntian Lou ◽  
Weiwei Chang ◽  
Tianyu Cui ◽  
Hongchang Qian ◽  
Luyao Huang ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Corrosion Inhibition ◽  
Steel Surface ◽  
Extracellular Polymeric Substances ◽  
Low Cost ◽  
Mechanical Damage ◽  
Corrosion Current ◽  
Shewanella Putrefaciens ◽  
Microbiologically Influenced Corrosion ◽  
Sterile Medium

AbstractMicrobiologically influenced corrosion inhibition (MICI) of Q235 carbon steel by biomineralization was investigated via a combination of surface analysis, electrochemistry, and scanning electrochemical microscopy (SECM). The results showed that Shewanella putrefaciens used the cell walls as the nucleation sites to induce the formation of a protective biomineralized layers which contained calcite and extracellular polymeric substances on the steel surface. The potentiodynamic polarization results demonstrated that the corrosion current density (icorr value) of the biomineralized steel surface was 0.38 μA cm−2, which was less than one-tenth that of the blank steel in a sterile medium (4.86 μA cm−2) after 14 days. The biomineralized layers presented wear resistance and could self-repair after undergoing mechanical damage under microbial conditions as verified by morphological and SECM observations. This work reveals that microbial-induced carbonate biomineralization, as a MICI approach, may be considered as a reliable, low-cost, environmentally friendly corrosion inhibition strategy.

Influence of Bacteria Pseudomonas fluorescens on the Properties of Latvian Clay

2014 ◽  
Vol 604 ◽  
pp. 208-211
Author(s):  
Maris Rundans ◽  
Ingunda Sperberga ◽  
Gaida Sedmale ◽  
Dagnija Vecstaudza ◽  
Olga Muter
Keyword(s):  
Soil Properties ◽  
Rheological Properties ◽  
Pseudomonas Fluorescens ◽  
Extracellular Polymeric Substances ◽  
Clay Soil ◽  
Atterberg Limits ◽  
Mineral Particles ◽  
Ft Ir ◽  
Growth Of Bacteria

Wide varieties of bacteria are able to produce extracellular polymeric substances (EPS) which are mostly composed of polysaccharides. It is suggested that EPS substances can alter certain clay soil properties due to their ability to adhere to the surface of mineral particles. Most common used microorganisms by the researchers for this purpose are of either genus Bacillus or genus Pseudomonas. In this study growth of bacteria P. fluorescens AM PS11 culture in locally obtained clay is studied for the purpose of establishing their influence on rheological properties of clay. An attempt to evaluate it has been made using FT-IR and XRD. Change in plasticity of clay using Atterberg limits method and coefficient of drying sensitivity has also been determined.

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