The Use of X-Ray Photoelectron Spectroscopy for the Study of Oral Streptococcal Cell Surfaces

1997 ◽  
Vol 11 (4) ◽  
pp. 388-394 ◽  
Author(s):  
H.C. Van Der Mei ◽  
H.J. Busscher
Keyword(s):  
Cell Surface ◽  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Contact Angles ◽  
Microbial Cell ◽  
Cell Surfaces ◽  
Water Contact ◽  
X Ray

Physicochemical and structural properties of microbial cell surfaces play an important role in their adhesion to surfaces and are determined by the chemical composition of the outermost cell surface. Many traditional methods used to determine microbial cell wall composition require fractionation of the organisms and consequently do not yield information about the composition of the outermost cell surface. X-ray photoelectron spectroscopy (XPS) measures the elemental composition of the outermost cell surfaces of micro-organisms. The technique requires freeze-drying of the organisms, but, nevertheless, elemental surface concentration ratios of oral streptococcal cell surfaces with peritrichously arranged surface structures showed good relationships with physicochemical properties measured under physiological conditions, such as zeta potentials. Isoelectric points ap-peared to be governed by the relative abundance of oxygen- and nitrogen-containing groups on the cell surfaces. Also, the intrinsic microbial cell-surface hydrophobicity by water contact angles related to the cell-surface composition as by XPS and was highest for strains with an elevated isoelectric point. Inclusion of elemental surface compositions for tufted streptococcal strains caused deterioration of the relationships found. Interestingly, hierarchical cluster analysis on the basis of the elemental surface compositions revealed that, of 36 different streptococcal strains, only four S. rattus as well as nine S. mitis strains were located in distinct groups, well separated from the other streptococcal strains, which were all more or less mixed in one group.

Surface composition, surface properties, and adhesiveness ofAzospirillum brasilense—variation during growth

1996 ◽  
Vol 42 (6) ◽  
pp. 548-556 ◽  
Author(s):  
Yves F. Dufrêne ◽  
Paul G. Rouxhet
Keyword(s):  
Cell Surface ◽  
Stationary Phase ◽  
Photoelectron Spectroscopy ◽  
Azospirillum Brasilense ◽  
Surface Composition ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Exponential Phase ◽  
Surface Proteins ◽  
X Ray

The surface chemical composition, the physicochemical properties, and the adhesiveness of Azospirillum brasilense have been investigated during growth in Luria–Bertani* rich medium. The surface elemental composition obtained by X-ray photoelectron spectroscopy was converted into a molecular composition in terms of model constituents: proteins, polysaccharides, and hydrocarbon-like compounds. The protein content increased during growth, from 30 (exponential phase cells) to 50% (stationary phase cells), concomitantly with a decrease in the polysaccharide content, from 60 to 35%. These modifications were related to a change in cell surface hydrophobicity, i.e., to an increase of the water contact angle from 20 to 60°. No difference of electrophoretic mobility was detected between cells harvested in the exponential phase and cells harvested in the stationary phase. The increase of both cell surface protein concentration and cell surface hydrophobicity during growth was correlated with an increase of cell adhesiveness to model supports. This points to the involvement of cell surface proteins and cell surface hydrophobicity in the adhesion process.Key words: Azospirillum brasilense, surface composition, hydrophobicity, adhesiveness, X-ray photoelectron spectroscopy.

scholarly journals X-Ray Photoelectron Spectroscopy on Microbial Cell Surfaces: A Forgotten Method for the Characterization of Microorganisms Encapsulated With Surface-Engineered Shells

2021 ◽  
Vol 9 ◽  
Author(s):  
Hao Wei ◽  
Xiao-Yu Yang ◽  
Henny C. van der Mei ◽  
Henk J. Busscher
Keyword(s):  
Cell Surface ◽  
Photoelectron Spectroscopy ◽  
Surface Characterization ◽  
Elevated Temperatures ◽  
High Vacuum ◽  
Microbial Cell ◽  
Cell Surfaces ◽  
Microbial Cells ◽  
X Ray ◽  
Freeze Dried

Encapsulation of single microbial cells by surface-engineered shells has great potential for the protection of yeasts and bacteria against harsh environmental conditions, such as elevated temperatures, UV light, extreme pH values, and antimicrobials. Encapsulation with functionalized shells can also alter the surface characteristics of cells in a way that can make them more suitable to perform their function in complex environments, including bio-reactors, bio-fuel production, biosensors, and the human body. Surface-engineered shells bear as an advantage above genetically-engineered microorganisms that the protection and functionalization added are temporary and disappear upon microbial growth, ultimately breaking a shell. Therewith, the danger of creating a “super-bug,” resistant to all known antimicrobial measures does not exist for surface-engineered shells. Encapsulating shells around single microorganisms are predominantly characterized by electron microscopy, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, particulate micro-electrophoresis, nitrogen adsorption-desorption isotherms, and X-ray diffraction. It is amazing that X-ray Photoelectron Spectroscopy (XPS) is forgotten as a method to characterize encapsulated yeasts and bacteria. XPS was introduced several decades ago to characterize the elemental composition of microbial cell surfaces. Microbial sample preparation requires freeze-drying which leaves microorganisms intact. Freeze-dried microorganisms form a powder that can be easily pressed in small cups, suitable for insertion in the high vacuum of an XPS machine and obtaining high resolution spectra. Typically, XPS measures carbon, nitrogen, oxygen and phosphorus as the most common elements in microbial cell surfaces. Models exist to transform these compositions into well-known, biochemical cell surface components, including proteins, polysaccharides, chitin, glucan, teichoic acid, peptidoglycan, and hydrocarbon like components. Moreover, elemental surface compositions of many different microbial strains and species in freeze-dried conditions, related with zeta potentials of microbial cells, measured in a hydrated state. Relationships between elemental surface compositions measured using XPS in vacuum with characteristics measured in a hydrated state have been taken as a validation of microbial cell surface XPS. Despite the merits of microbial cell surface XPS, XPS has seldom been applied to characterize the many different types of surface-engineered shells around yeasts and bacteria currently described in the literature. In this review, we aim to advocate the use of XPS as a forgotten method for microbial cell surface characterization, for use on surface-engineered shells encapsulating microorganisms.

scholarly journals Bacterial factors influencing adhesion of Pseudomonas aeruginosa strains to a poly(ethylene oxide) brush

Microbiology ◽  
2006 ◽  
Vol 152 (9) ◽  
pp. 2673-2682 ◽  
Author(s):  
Astrid Roosjen ◽  
Henk J. Busscher ◽  
Willem Norde ◽  
Henny C. van der Mei
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Ethylene Oxide ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Contact Angles ◽  
Bacterial Strains ◽  
Water Contact ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Brush Coating

Most bacterial strains adhere poorly to poly(ethylene oxide) (PEO)-brush coatings, with the exception of a Pseudomonas aeruginosa strain. The aim of this study was to find factors determining whether P. aeruginosa strains do or do not adhere to a PEO-brush coating in a parallel plate flow chamber. On the basis of their adhesion, a distinction could be made between three adhesive and three non-adhesive strains of P. aeruginosa, while bacterial motilities and zeta potentials were comparable for all six strains. However, water contact angles indicated that the adhesive strains were much more hydrophobic than the non-adhesive strains. Furthermore, only adhesive strains released surfactive extracellular substances, which may be engaged in attractive interactions with the PEO chains. Atomic force microscopy showed that the adhesion energy, measured from the retract curves of a bacterial-coated cantilever from a brush coating, was significantly more negative for adhesive strains than for non-adhesive strains (P<0.001). Through surface thermodynamic and extended-DLVO (Derjaguin, Landau, Verwey, Overbeek) analyses, these stronger adhesion energies could be attributed to acid–base interactions. However, the energies of adhesion of all strains to a brush coating were small when compared with their energies of adhesion to a glass surface. Accordingly, even the adhesive P. aeruginosa strains could be easily removed from a PEO-brush coating by the passage of a liquid–air interface. In conclusion, cell surface hydrophobicity and surfactant release are the main factors involved in adhesion of P. aeruginosa strains to PEO-brush coatings.

Nanostructured TiO2 modified by perfluoropolyethers: Gas phase photocatalytic activity

2010 ◽  
Vol 25 (1) ◽  
pp. 96-103 ◽  
Author(s):  
Claudia L. Bianchi ◽  
Silvia Ardizzone ◽  
Giuseppe Cappelletti ◽  
Giuseppina Cerrato ◽  
Walter Navarrini ◽  
...  
Keyword(s):  
Gas Phase ◽  
Surface Area ◽  
Photoelectron Spectroscopy ◽  
Surface Composition ◽  
High Surface ◽  
Ammonium Phosphate ◽  
Water Contact ◽  
Electronic Band ◽  
X Ray ◽  
Bet Analysis

A high-molecular-weight perfluoropolyether (PFPE-YR) and a perfluoropolyether containing ammonium phosphate (PFPE-F10) have been evaluated as fluorinated coating for high-surface-area titanium oxides. Coated nano-TiO2 shows hydrophobic properties and excellent buoyancy on water. In addition to photoactivity toward the degradation of toluene in gas phase, specific trial analyses have been completed to estimate the modified titanium oxide features. Brunauer–Emmett–Teller (BET) analysis for the surface area determination, ultraviolet-visible spectroscopy (UV-Vis) for the material electronic band gap, high-resolution transmission electron microscopy (HRTEM), x-ray diffraction (XRD), and x-ray photoelectron spectroscopy (XPS) for the morphology, structure, and surface composition, respectively, and water contact angle and infrared (IR) analysis have been performed to estimate the wettability and stability of coated titanium.

scholarly journals Heterologous Inducible Expression ofEnterococcus faecalis pCF10 Aggregation Substance Asc10 inLactococcus lactis and Streptococcus gordonii Contributes to Cell Hydrophobicity and Adhesion to Fibrin

2000 ◽  
Vol 182 (8) ◽  
pp. 2299-2306 ◽  
Author(s):  
Helmut Hirt ◽  
Stanley L. Erlandsen ◽  
Gary M. Dunny
Keyword(s):  
Cell Surface ◽  
Cell Surface Hydrophobicity ◽  
Regulatory System ◽  
Surface Hydrophobicity ◽  
Bacterial Cells ◽  
Streptococcus Gordonii ◽  
Cell Surfaces ◽  
Gene Encoding ◽  
Aggregation Substance

ABSTRACT Aggregation substance proteins encoded by the sex pheromone plasmid family of Enterococcus faecalis have been shown previously to contribute to the formation of a stable mating complex between donor and recipient cells and have been implicated in the virulence of this increasingly important nosocomial pathogen. In an effort to characterize the protein further, prgB, the gene encoding the aggregation substance Asc10 on pCF10, was cloned in a vector containing the nisin-inducible nisA promoter and its two-component regulatory system. Expression of aggregation substance after nisin addition to cultures of E. faecalis and the heterologous bacteria Lactococcus lactis andStreptococcus gordonii was demonstrated. Electron microscopy revealed that Asc10 was presented on the cell surfaces ofE. faecalis and L. lactis but not on that ofS. gordonii. The protein was also found in the cell culture supernatants of all three species. Characterization of Asc10 on the cell surfaces of E. faecalis and L. lactisrevealed a significant increase in cell surface hydrophobicity upon expression of the protein. Heterologous expression of Asc10 on L. lactis also allowed the recognition of its binding ligand (EBS) on the enterococcal cell surface, as indicated by increased transfer of a conjugative transposon. We also found that adhesion of Asc10-expressing bacterial cells to fibrin was elevated, consistent with a role for the protein in the pathogenesis of enterococcal endocarditis. The data demonstrate that Asc10 expressed under the control of the nisA promoter in heterologous species will be an useful tool in the detailed characterization of this important enterococcal conjugation protein and virulence factor.

X-ray photoelectron spectroscopy for the study of microbial cell surfaces

2000 ◽  
Vol 39 (1) ◽  
pp. 1-24 ◽  
Author(s):  
H.C. van der Mei ◽  
J. de Vries ◽  
H.J. Busscher
Keyword(s):  
Photoelectron Spectroscopy ◽  
Microbial Cell ◽  
Cell Surfaces ◽  
X Ray
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