Influence of oxygen limitation on the cell surface properties of bacteria from activated sludge

1998 ◽  
Vol 37 (4-5) ◽  
pp. 349-352 ◽  
Author(s):  
R. Palmgren ◽  
F. Jorand ◽  
P. H. Nielsen ◽  
J. C. Block
Keyword(s):  
Cell Surface ◽  
Activated Sludge ◽  
Surface Properties ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Growth Conditions ◽  
Oxygen Limitation ◽  
Cell Surface Properties ◽  
Number Of Factors ◽  
Math Test

Cell surface hydrophobicity is believed to be important to flocculation in activated sludge and biofilm systems. Optimization of these processes includes changes in the growth conditions of the bacteria. A number of factors influence cell surface hydrophobicity. The influence of oxygen on the cell surface hydrophobicity of 4 bacteria isolated from activated sludge was tested. The bacteria were grown in batch cultures with and without oxygen limitation. It was found that oxygen limitation generally caused a lowering of the cell surface hydrophobicity. The study also showed that there are many difficulties in measuring cell surface hydrophobicity since other cell surface properties, such as surface charge, influence the measurement methods. The MATH test was employed to establish how assay conditions influenced the results.

In situ detection of cell surface hydrophobicity of probe-defined bacteria in activated sludge

2001 ◽  
Vol 43 (6) ◽  
pp. 97-103 ◽  
Author(s):  
J. L. Nielsen ◽  
L. H. Mikkelsen ◽  
P. H. Nielsen
Keyword(s):  
Activated Sludge ◽  
Surface Properties ◽  
Treatment Plant ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Substrate Uptake ◽  
Filamentous Bacteria ◽  
In Situ Conditions ◽  
Bacterial Surfaces

The surface hydrophobicity of different types of bacteria in activated sludge were investigated under in situ conditions by following the adhesion of fluorescent microspheres with defined surface properties to bacterial surfaces (the MAC-method). This technique was combined with identification of the bacteria with fluorescence in situ hybridization with rRNA-targeted oligonucleotides (FISH) and could thus be used for characterization of surface properties of probe-defined bacteria directly in a complex system without prior enrichment or isolation. This MAC-FISH technique could be used for single bacteria as well as filamentous bacteria. In the investigated activated sludge from an industrial wastewater treatment plant, two types of filamentous bacteria dominated. One morphotype consistently attracted only very few hydrophobic microspheres, indicating that the thin sheath of exopolymers around the cells had a hydrophilic surface. Use of a hierarchical set of gene probes revealed that these filaments were sulphide oxidising Thiothrix spp. The other predominating filamentous morphotype had a thick, very hydrophobic exopolymeric sheath. This filamentous bacterium was found to belong to the alpha-Proteobacteria. The relevance of the significant differences in surface hydrophobicity for the two morphotypes in respect to substrate uptake and floc formation is discussed.

Changes in Cell Surface Properties of Shiga Toxigenic Escherichia coli by Quercus infectoria G. Olivier

2009 ◽  
Vol 72 (8) ◽  
pp. 1699-1704 ◽  
Author(s):  
SUPAYANG PIYAWAN VORAVUTHIKUNCHAI ◽  
SAKOL SUWALAK
Keyword(s):  
Escherichia Coli ◽  
Cell Surface ◽  
Surface Properties ◽  
Cell Surface Hydrophobicity ◽  
Ethanolic Extract ◽  
Bacterial Cells ◽  
Electron Microscopic ◽  
Cell Surface Properties ◽  
E Coli ◽  
Quercus Infectoria

The effects of Quercus infectoria (family Fagaceae) nutgalls on cell surface properties of Shiga toxigenic Escherichia coli (STEC) were investigated with an assay of microbial adhesion to hydrocarbon. The surface of bacterial cells treated with Q. infectoria exhibited a higher level of cell surface hydrophobicity (CSH) toward toluene than did the surface of untreated cells. With 50% ethanolic extract, the CSH of the three strains of STEC O157:H7 treated with 4× MIC of the extract resulted in moderate or strong hydrophobicity, whereas at 2× MIC and MIC, the CSH of only one strain of E. coli O157:H7 was significantly affected. The 95% ethanolic extract had a significant effect on CSH of all three strains at both 4× MIC and 2× MIC but not at the MIC. The effect on bacterial CSH was less pronounced with the other STEC strains. At 4× MIC, the 50% ethanolic extract increased the CSH of all non-O157 STEC strains significantly. At 2× MIC and 4× MIC, the 95% ethanolic extract affected the CSH of E. coli O26:H11 significantly but did not affect E. coli O111:NM or E. coli O22. Electron microscopic examination revealed the loss of pili in the treated cells. The ability of Q. infectoria extract to modify hydrophobic domains enables this extract to partition the lipids of the bacterial cell membrane, rendering the membrane more permeable and allowing leakage of ions and other cell contents, which leads to cell death. Further studies are required to evaluate the effects of Q. infectoria extract in food systems or in vivo and provide support for the use of this extract as a food additive for control of these STEC pathogens.

scholarly journals Biofilm Formation and Cell Surface Properties among Pathogenic and Nonpathogenic Strains of the Bacillus cereus Group

2009 ◽  
Vol 75 (20) ◽  
pp. 6616-6618 ◽  
Author(s):  
Sandrine Auger ◽  
Nalini Ramarao ◽  
Christine Faille ◽  
Agnès Fouet ◽  
Stéphane Aymerich ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cell Surface ◽  
Bacillus Cereus ◽  
Digestive Tract ◽  
Biofilm Formation ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Bacillus Cereus Group ◽  
Cell Surface Properties ◽  
Tract Infections

ABSTRACT Biofilm formation by 102 Bacillus cereus and B. thuringiensis strains was determined. Strains isolated from soil or involved in digestive tract infections were efficient biofilm formers, whereas strains isolated from other diseases were poor biofilm formers. Cell surface hydrophobicity, the presence of an S layer, and adhesion to epithelial cells were also examined.

Differential surface localization and temperature-dependent expression of the Candida albicans CSH1 protein

Microbiology ◽  
2004 ◽  
Vol 150 (2) ◽  
pp. 285-292 ◽  
Author(s):  
David R. Singleton ◽  
Kevin C. Hazen
Keyword(s):  
Candida Albicans ◽  
Cell Surface ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Growth Conditions ◽  
Northern Blotting ◽  
Temperature Dependent ◽  
Cell Surface Biotinylation ◽  
Extracellular Compartment ◽  
Primary Amino

Cell-surface hydrophobicity (CSH) in Candida albicans contributes to virulence and can be conveniently regulated in planktonic cultures by altering growth temperature. The CSH1 gene is the first candidate gene that has been demonstrated to play a role in affecting the CSH phenotype. However, the primary amino acid sequence of the CSH1 gene product suggests that the protein should be restricted to the cytoplasm. A majority of the protein appears to demonstrate that localization. Cell-surface biotinylation and limited glucanase digestion were used to determine and estimate the relative amount of Csh1p in the extracellular compartment in comparison to the cytoplasmic pool. Additionally, Western and Northern blotting were used to assess expression of the CSH1 gene under different growth conditions. Compared with cells grown at 23 °C, the total cellular levels of Csh1p are significantly greater at elevated growth temperatures. Detection of Csh1p on the cell surface correlates with the level of overall protein expression. The temperature-dependent regulation and surface presentation of Csh1p suggests a mechanism for regulating the CSH phenotype.

SubMICs of penicillin and erythromycin enhance biofilm formation and hydrophobicity of Corynebacterium diphtheriae strains

2013 ◽  
Vol 62 (5) ◽  
pp. 754-760 ◽  
Author(s):  
D. L. R. Gomes ◽  
R. S. Peixoto ◽  
E. A. B. Barbosa ◽  
F. Napoleão ◽  
P. S. Sabbadini ◽  
...  
Keyword(s):  
Cell Surface ◽  
Surface Properties ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Corynebacterium Diphtheriae ◽  
Surface Charges ◽  
Bacterial Surface ◽  
Bacterial Morphology

Subinhibitory concentrations (subMICs) of antibiotics may alter bacterial surface properties and change microbial physiology. This study aimed to investigate the effect of a subMIC (⅛ MIC) of penicillin (PEN) and erythromycin (ERY) on bacterial morphology, haemagglutinating activity, cell-surface hydrophobicity (CSH) and biofilm formation on glass and polystyrene surfaces, as well as the distribution of cell-surface acidic anionic residues of Corynebacterium diphtheriae strains (HC01 tox − strain; CDC-E8392 and 241 tox + strains). All micro-organisms tested were susceptible to PEN and ERY. Growth in the presence of PEN induced bacterial filamentation, whereas subMIC of ERY caused cell-size reduction of strains 241 and CDC-E8392. Adherence to human erythrocytes was reduced after growth in the presence of ERY, while CSH was increased by a subMIC of both antibiotics in bacterial adherence to n-hexadecane assays. Conversely, antibiotic inhibition of biofilm formation was not observed. All strains enhanced biofilm formation on glass after treatment with ERY, while only strain 241 increased glass adherence after cultivation in the presence of PEN. Biofilm production on polystyrene surfaces was improved by ⅛ MIC of ERY. After growth in the presence of both antimicrobial agents, strains 241 and CDC-E8392 exhibited anionic surface charges with focal distribution. In conclusion, subMICs of PEN and ERY modified bacterial surface properties and enhanced not only biofilm formation but also cell-surface hydrophobicity. Antibiotic-induced biofilm formation may contribute to the inconsistent success of antimicrobial therapy for C. diphtheriae infections.

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