The formation of microcolonies by rumen bacteria

1980 ◽  
Vol 26 (9) ◽  
pp. 1104-1113 ◽  
Author(s):  
K.-J. Cheng ◽  
J. W. Costerton
Keyword(s):  
Electron Microscopy ◽  
Rumen Fluid ◽  
Ruthenium Red ◽  
Solid Surfaces ◽  
Morphological Data ◽  
Specimen Preparation ◽  
Rumen Bacteria ◽  
Fibrous Matrix ◽  
Ruthenium Red Staining ◽  
Exchange Function

When rumen fluid is fixed for electron microscopy, without centrifugation, a large amount of material sediments spontaneously and ruthenium red staining shows this material to be partially composed of bacterial microcolonies in which morphologically similar sister cells are enclosed in an extensive fibrous exopolysaccharide glycocalyx. The exopolysaccharide matrix condenses, to variable degrees, during the dehydration steps of specimen preparation for electron microscopy but some fibers are stabilized by their attachment to solid surfaces at multiple points and the extent of this matrix can be deduced from morphological data. Even after condensation, the glycocalyces of rumen bacteria occupy more space than the cells themselves and they completely surround most cells with a fibrous matrix, whose chemical composition dictates an ion-exchange function, that must be assumed to be protective against some bacteriophage and antibacterial agents.

Morphology and ultrastructure of oral strains of Actinobacillus actinomycetemcomitans and Haemophilus aphrophilus

1980 ◽  
Vol 30 (2) ◽  
pp. 588-600
Author(s):  
S C Holt ◽  
A C Tanner ◽  
S S Socransky
Keyword(s):  
Electron Microscopy ◽  
Ruthenium Red ◽  
Actinobacillus Actinomycetemcomitans ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Large Numbers ◽  
Haemophilus Aphrophilus ◽  
Ruthenium Red Staining ◽  
Amorphous Surface ◽  
Scanning Electron

Selected human oral and nonoral strains of the genera Actinobacillus and Haemophilus were examined by transmission and scanning electron microscopy. The strains examined were morphologically identical to recognized Actinobacillus actinomycetemcomitans, Haemophilus aphrophilus, and Haemophilus paraphrophilus. By transmission electron microscopy, the cells were typically gram negative in morphology, with several strains possessing some extracellular ruthenium red-staining polymeric material. Numerous vesicular structures, morphologically identical to lipopolysaccharide vesicles, were seen to originate from and be continuous with the surface of the outer membrane. Large numbers of these vesicles were also found in the external environment. Scanning electron microscopic observations revealed that both actinobacilli and haemophili possessed surface projections and an amorphous surface material which connected and covered adjacent cells.

Observation of exopolysaccharides (EPS) from Lactobacillus helveticus SBT2171 using the Tokuyasu method

Microscopy ◽  
2020 ◽  
Vol 69 (5) ◽  
pp. 286-290
Author(s):  
Takamichi Kamigaki ◽  
Akihiro Ogawa
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Colloidal Gold ◽  
Ruthenium Red ◽  
Lactobacillus Helveticus ◽  
Ruthenium Red Staining ◽  
Observation Method ◽  
Β Lactoglobulin

Abstract Some species of lactic acid bacteria used for the production of natural cheese produce exopolysaccharides (EPS). Electron microscopy is useful for analyzing the microstructure of EPS produced by lactic acid bacteria. However, pretreatments used to observe the microstructure of EPS by electron microscopy, such as dehydration and resin embedding, can result in EPS flowing out easily from the cell. Therefore, in this study, the Tokuyasu method was conducted on cryosection to reduce EPS outflow. Two types of observation method, namely, using lectin and ruthenium red, were conducted in an attempt to observe EPS produced by Lactobacillus helveticus SBT2171. Observation using the lectin method confirmed that colloidal gold particles conjugated with a lectin recognizing β-galactoside were present in the capsule. Structures that appeared to be β-galactoside-containing slime polysaccharides that were released from the cell wall were also observed. Observation using ruthenium red showed that capsular polysaccharides (CPS) in the capsule were present as a net-like structure. Colloidal gold conjugation with an anti-β-lactoglobulin antibody, in addition to ruthenium red staining, allowed the identification of slime polysaccharides released from the cell wall in the milk protein network derived from the culture medium. Based on these results, the Tokuyasu method was considered to be a useful pretreatment method to clarify and observe the presence of EPS. In particular, both CPS in the capsule and slime exopolysaccharides released from the cell wall were visualized.

Electron microscopic localization of sulfated glycosaminoglycans and proteoglycans in pleomorphic adenomas

1983 ◽  
Vol 41 ◽  
pp. 774-775
Author(s):  
Ronald Lam
Keyword(s):  
Electron Microscopy ◽  
Myoepithelial Cells ◽  
Mesenchymal Cells ◽  
Ruthenium Red ◽  
Major Salivary Gland ◽  
Electron Microscopic ◽  
Ultrastructural Studies ◽  
Pleomorphic Adenomas ◽  
Cellular Source ◽  
Ruthenium Red Staining

Although “myoepithelial” cells in pleomorphic adenomas have been implicated by several ultrastructural studies as responsible for the production of myxomatous and chondroid stroma, the cellular source of stromal glycosaminoglycans and proteoglycans has yet to be demonstrated histochemically by electron microscopy.Three major salivary gland pleomorphic adenomas were examined by electron microscopy after fixation in 2.5% glutaraldehyde and in 0.2% ruthenium red-glutaraldehyde. Routine ultrastructural preparations revealed a spectrum of cells with epithelial and mesenchymal features. The mesenchymal cells in the myxoid region displayed intracytoplasmic 70-80Å microfilaments, prominent Golgi complex, RER, and secretory vesicles. The fine structural appearance with ruthenium red stained tissue was similar to that of routine preparations. However, with ruthenium red staining, proteoglycans of the myxoid stroma could be visualized as numerous extracellular 250-500Å polygonal matrix granules with fine projecting filaments (Fig. 1A). Similar positive ruthenium red stained intracellular granules were observed within the cytoplasmic vacuoles of the mesenchymal cells, a feature not present in cells with epithelial differentiation (Fig. 1B).

scholarly journals Microplicae: characteristic ridge-like folds of the plasmalemma.

1976 ◽  
Vol 68 (3) ◽  
pp. 420-429 ◽  
Author(s):  
P M Andrews
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Alimentary Tract ◽  
Ruthenium Red ◽  
Specific Function ◽  
Free Surfaces ◽  
Transmission Electron ◽  
Dense Zone ◽  
Ruthenium Red Staining ◽  
Scanning Electron

Scanning electron microscopy reveals that the free surfaces of stratified squamous epithelial cells lining the alimentary tract, cornea, and conjunctiva exhibit characteristic ridge-like folds of plasmalemma. These microplicae are approximately 0.1-0.2 micronm in width, of variable height (0.2-0.8 micronm) and length, may followstraight or winding paths, often branch, and exhibit a wide variety of patterns over the surfaces of cells. Transmission electron microscopy reveals that microplicae often have a fine (100-150 A) electron-dense zone subjacent to their plasmalemma and an intracellular matrix characterized by a disorderly arrary of fine filaments (40-60 A in diameter). Microplicae appear to arise from plasmalemmal fold which once provided for intercellular interdigitation and desmosome abhesion between adjacent cells. Ruthenium red staining demonstrates that microplicae and interplical grooves are covered with a polyanionic glycocalyx. Although free surface microplicae may merely represent the renmants of intercellular interdigitations or a modified expression of microvillous-like extensions, it is also possible that they serve another specific function. In this regard it is speculated that microplical and interplical grooves may function to hold a layer of lubricating and cushioning mucin designed to protect the underlying plasmalemma from abrasive abuse.

scholarly journals Evidence for Mucin-Like Glycoproteins That Tether Sporozoites of Cryptosporidium parvum to the Inner Surface of the Oocyst Wall

2009 ◽  
Vol 9 (1) ◽  
pp. 84-96 ◽  
Author(s):  
Anirban Chatterjee ◽  
Sulagna Banerjee ◽  
Martin Steffen ◽  
Roberta M. O'Connor ◽  
Honorine D. Ward ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Monoclonal Antibodies ◽  
Cryptosporidium Parvum ◽  
Oral Route ◽  
Ruthenium Red ◽  
Oocyst Wall ◽  
Maclura Pomifera ◽  
Inner Surface ◽  
Ruthenium Red Staining ◽  
Binding Lectin

ABSTRACT Cryptosporidium parvum oocysts, which are spread by the fecal-oral route, have a single, multilayered wall that surrounds four sporozoites, the invasive form. The C. parvum oocyst wall is labeled by the Maclura pomifera agglutinin (MPA), which binds GalNAc, and the C. parvum wall contains at least two unique proteins ( C ryptosporidium oocyst wall protein 1 [COWP1] and COWP8) identified by monoclonal antibodies. C. parvum sporozoites have on their surface multiple mucin-like glycoproteins with Ser- and Thr-rich repeats (e.g., gp40 and gp900). Here we used ruthenium red staining and electron microscopy to demonstrate fibrils, which appear to attach or tether sporozoites to the inner surface of the C. parvum oocyst wall. When disconnected from the sporozoites, some of these fibrillar tethers appear to collapse into globules on the inner surface of oocyst walls. The most abundant proteins of purified oocyst walls, which are missing the tethers and outer veil, were COWP1, COWP6, and COWP8, while COWP2, COWP3, and COWP4 were present in trace amounts. In contrast, MPA affinity-purified glycoproteins from C. parvum oocysts, which are composed of walls and sporozoites, included previously identified mucin-like glycoproteins, a GalNAc-binding lectin, a Ser protease inhibitor, and several novel glycoproteins (C. parvum MPA affinity-purified glycoprotein 1 [CpMPA1] to CpMPA4). By immunoelectron microscopy (immuno-EM), we localized mucin-like glycoproteins (gp40 and gp900) to the ruthenium red-stained fibrils on the inner surface wall of oocysts, while antibodies to the O-linked GalNAc on glycoproteins were localized to the globules. These results suggest that mucin-like glycoproteins, which are associated with the sporozoite surface, may contribute to fibrils and/or globules that tether sporozoites to the inner surface of oocyst walls.

Electron microscopy of an endoparasitic fungus, Gonimochaete pyriforme, infecting nematodes

1985 ◽  
Vol 63 (12) ◽  
pp. 2326-2331 ◽  
Author(s):  
Masatoshi Saikawa ◽  
Takashi Anazawa
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Electron Density ◽  
Germ Tube ◽  
Adhesive Layer ◽  
Ruthenium Red ◽  
Ruthenium Red Staining ◽  
Dense Vesicles

Gonimochaete pyriforme Barron was studied using the electron microscope. Protoplasm in the pyriform-shaped aplanospore is filled with electron-dense vesicles (0.1–0.3 μm) except at the base where it is vacuolated. The globose knob at the apical end of the spore is covered with a very thin adhesive layer (ca. 0.1 μm) whose electron density is slightly enhanced by ruthenium red staining but which does not show a fibrillose appearance. After attachment to the nematode's cuticle, a narrow germ tube (0.15 μm) arises from the globose knob and penetrates through the adhesive layer and the host's cuticle into the nematode body. The adhesive knob of the aplanospore in G. pyriforme is very similar in ultrastructure to the encysted zoospore of Myzocytium humicola Barron and Percy in the Lagenidiales after the cyst has germinated.

Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

Ruthenium Red Staining of Human Hard Keratin Fibers

1982 ◽  
Vol 40 ◽  
pp. 278-279
Author(s):  
M. C. Buhrer ◽  
R. A. Mathews
Keyword(s):  
Human Hair ◽  
Ruthenium Red ◽  
Acid Mucopolysaccharides ◽  
Biochemical Studies ◽  
Keratin Fibers ◽  
Ruthenium Red Staining ◽  
Extracellular Materials

Ruthenium red has been used as a stain to demonstrate a variety of extracellular materials, especially acid mucopolysaccharides. It also reacts with certain intracellular and extracellular lipids. Since biochemical studies in our laboratory demonstrated the presence of a variety of monosaccharides in human hair ruthenium red staining procedures were adopted in order to evaluate the presence and morphological location of acid oligosaccharides in the keratinized aspect of hair.

The ionic strength dependence of chromatin folding

1978 ◽  
Vol 36 (2) ◽  
pp. 220-221
Author(s):  
F. Thoma ◽  
TH. Koller
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Ionic Strength ◽  
Specimen Preparation ◽  
Preparation Technique ◽  
Carbon Supports ◽  
Ionic Strength Dependence ◽  
Chromatin Folding ◽  
Strength Dependence ◽  
Preparation Techniques

Under a variety of electron microscope specimen preparation techniques different forms of chromatin appearance can be distinguished: beads-on-a-string, a 100 Å nucleofilament, a 250 Å fiber and a compact 300 to 500 Å fiber.Using a standardized specimen preparation technique we wanted to find out whether there is any relation between these different forms of chromatin or not. We show that with increasing ionic strength a chromatin fiber consisting of a row of nucleo- somes progressively folds up into a solenoid-like structure with a diameter of about 300 Å.For the preparation of chromatin for electron microscopy the avoidance of stretching artifacts during adsorption to the carbon supports is of utmost importance. The samples are fixed with 0.1% glutaraldehyde at 4°C for at least 12 hrs. The material was usually examined between 24 and 48 hrs after the onset of fixation.

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