A Study of the Structure of the Cell Wall of Spirillum Serpens Using Frozen, Hydrated Specimens

1976 ◽  
Vol 34 ◽  
pp. 136-137
Author(s):  
Kenneth A. Taylor ◽  
David A. Grano ◽  
Wah Chiu
Keyword(s):  
Cell Wall ◽  
Negative Bacterium ◽  
Electron Microscopic ◽  
Identical Particles ◽  
Gram Negative ◽  
Microscopic Studies ◽  
Hexagonal Arrangement

Based on chemical and electron microscopic studies (Buckmire and Murray, 1970), the cell wall of Spirillum serpens VHA, a Gram-negative bacterium, is composed of several components including protein, lipopolysaccharide, and peptidoglycan. By a gentle heating of the bacteria at 60°C, the outermost components of the cell wall are separated from the rest of the cell, and can be purified by simple procedures. In the negatively stained preparations, it has been shown by Buckmire and Murray that these components appear in both lamellar and tubular forms made up of identical particles in a closely packed hexagonal arrangement. These particles are approximately 90 Å in diameter, with a center-to-center spacing of approximately 150 Å, and are connected by Y-shaped links.

Electron microscopic studies on the formation of vesicular bodies during cell wall degradation and regeneration in yeast

1977 ◽  
Vol 17 (4) ◽  
pp. 293-297
Author(s):  
V. V. Dmitriev ◽  
A. B. Tsiomenko ◽  
E. N. Ratner ◽  
V. K. Akimenko ◽  
B. A. Fikhte
Keyword(s):  
Cell Wall ◽  
Cell Wall Degradation ◽  
Electron Microscopic ◽  
Microscopic Studies

scholarly journals ELECTRON MICROSCOPIC STUDIES ON THE INDIRECT FLIGHT MUSCLES OF DROSOPHILA MELANOGASTER

1963 ◽  
Vol 17 (2) ◽  
pp. 351-362 ◽  
Author(s):  
S. Ahmad Shafiq
Keyword(s):  
Drosophila Melanogaster ◽  
Epidermal Cells ◽  
Uniform Density ◽  
Electron Microscopic ◽  
Thick Filaments ◽  
Irregular Pattern ◽  
Regular Arrangement ◽  
Microscopic Studies ◽  
Hexagonal Arrangement ◽  
Flight Muscles

The myofibrils in Drosophila have thick and thin types of myofilaments arranged in the hexagonal pattern described for Calliphora by Huxley and Hanson (15). The thick filaments, along most of their length in the A band, seem to be binary in structure, consisting of a dense cortex and a lighter medulla. In the H zone, however, they show more uniform density; lateral projections (bridges) also appear to be absent in this region. The M band has a varying number of granules (probably of glycogen) distributed between the myofilaments. The myofilaments on reaching the Z region appear to change their hexagonal arrangement and become connected to one another by Z filaments. The regular arrangement of the filaments found in most regions of the fibrils is not seen in the terminal sarcomeres of some flight muscles; the two types of filaments appear to be intermingled in an irregular pattern in these parts of the fibrils. The attachment of myofibrils to the cuticle through the epidermal cells is described.

Electron microscopic studies on the formation of vesicular bodies during cell wall degradation and regeneration in yeast

1977 ◽  
Vol 17 (4) ◽  
pp. 293-297 ◽  
Author(s):  
V. V. Dmitriev ◽  
A. B. Tsiomenko ◽  
E. N. Ratner ◽  
V. K. Akimenko ◽  
B. A. Fikhte
Keyword(s):  
Cell Wall ◽  
Cell Wall Degradation ◽  
Electron Microscopic ◽  
Microscopic Studies

Electron Microscopic Observations on the Effects of Polymixin B Sulfate to Cell Walls of Chlamydia Organisms

1972 ◽  
Vol 30 ◽  
pp. 326-327
Author(s):  
Akira Matsumoto
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Present Report ◽  
Bactericidal Effect ◽  
Chlamydia Psittaci ◽  
Gram Negative Bacteria ◽  
Electron Microscopic ◽  
Cell Content ◽  
Gram Negative ◽  
Reticulate Body

Cell walls of the both types of bodies, mature elementary body(EB) and developmental reticulate body(RB) of Chlamydia psittaci appear the triple layered membrane in thin section. However, in the preparations shadowcast or stained negatively EB cell wall shows hexagonally arrayed structure composed of subunits, 180A in diameter on the inside surface, whereas RB cell wall does not have this structure. Chemical analysis demonstrated that EB cell wall contained a similar amino acid composition with the cell walls of gram-negative bacteria, such as E.coli. The bactericidal effect of polymixin group against gram-negative bacilli is understood that the drug affects to the cell wall and destroys its osmotic regulation. Electron microscopy on the effects of the drug against the gram-negative bacteria revealed the formation of numerous number of projections on the cell wall surface and leakage of cell content through the projections. The present report is concerned with further studies on the fine structure of EB cell walls based on the observation on their response to polymixin B sulfate.

scholarly journals ELECTRON MICROSCOPIC STUDIES ON STREPTOCOCCI

1969 ◽  
Vol 130 (5) ◽  
pp. 1063-1091 ◽  
Author(s):  
John Swanson ◽  
Konrad C. Hsu ◽  
Emil C. Gotschlich
Keyword(s):  
Cell Wall ◽  
Nitrous Acid ◽  
Intact Cell ◽  
M Protein ◽  
Acid Extraction ◽  
Electron Microscopic ◽  
Streptococcal Cell Wall ◽  
Before And After ◽  
Specific Polysaccharide ◽  
Microscopic Studies

The presence of M antigens on group A streptococci is associated with hairlike fimbriae that cover the surface of the streptococcal cell wall and are demonstrable by electron microscopy. These fimbriae also may be associated with R antigen. Like M protein, the surface fimbriae are destroyed by trypsin treatment and reappear when "trypsinized" streptococci are reincubated in fresh, trypsin-free broth. Ferritin-conjugated, type-specific antibodies localize on homologous M+ cells in a pattern suggestive of several M antigenic sites along the length of individual surface fimbria. The M-associated fimbriae remain on the residual cell wall after removal of the bulk of group-specific polysaccharide through nitrous acid extraction. This suggests attachment of the fimbriae to the mucopeptide and minor polysaccharide components remaining in the nitrous acid-extracted wall. The pattern of localization of ferritin-conjugated antibodies on homologous streptococci before and after trypsin exposure and upon reincubation of the trypsinized cells in fresh medium suggests the following hypothesis: M antigen is secreted by the cell, is partially excreted through the otherwise intact cell wall, and is bound by the wall so that M protein occupies a peripheral, exposed position on the surfaces of the streptococcal cell wall.

scholarly journals ELECTRON MICROSCOPIC STUDIES ON STREPTOCOCCI

1973 ◽  
Vol 138 (1) ◽  
pp. 245-258 ◽  
Author(s):  
John Swanson ◽  
Emil C. Gotschlich
Keyword(s):  
Cell Wall ◽  
Horseradish Peroxidase ◽  
Electron Microscopic ◽  
Streptococcal Cell Wall ◽  
Outermost Surface ◽  
Laminar Distribution ◽  
Specific Polysaccharide ◽  
Microscopic Studies ◽  
Group A ◽  
Protein Cell

The location of Group A carbohydrate in the streptococcal cell wall has been studied by several ultrastructural techniques. The findings, based largely on use of ferritin- and horseradish peroxidase-conjugated antibodies, are interpreted as demonstrating a discrete laminar distribution of the group-specific polysaccharide. This carbohydrate layer is located on the outermost surface of the cell wall in organisms lacking protein cell wall antigens.

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