The effect of aculeacin A and papulacandin B on morphology and cell wall ultrastructure in Candida albicans

1984 ◽  
Vol 30 (6) ◽  
pp. 857-863 ◽  
Author(s):  
J. J. Bozzola ◽  
R. J. Mehta ◽  
L. J. Nisbet ◽  
J. R. Valenta
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Candida Albicans ◽  
Cell Walls ◽  
Cell Necrosis ◽  
Wall Ultrastructure ◽  
Dividing Cells ◽  
Complete Cell ◽  
Aculeacin A ◽  
Scanning Electron

Transmission (TEM) and scanning electron microscopy (SEM) of Candida albicans cultures treated with the cell wall active antibiotics aculeacin A and papulacandin B (10 μg/mL) revealed highly distorted, wrinkled, and collapsed cells. Dividing cells failed to separate properly and aggregates of enlarged and elongated forms were often seen. TEM sections revealed thick and layered cell walls in the treated cultures and bud cross walls failed to segregate completely. Approximately 20% of the cells demonstrated complete cell necrosis accompanied with cytoplasmic deterioration, layered and distorted walls, and improperly formed buds and scars.

Chemical and enzymatic changes in the cell walls of Candida albicans and Saccharomyces cerevisiae by scanning electron microscopy

1980 ◽  
Vol 26 (8) ◽  
pp. 965-970 ◽  
Author(s):  
Yvonne Koch ◽  
K. H. Rademacher
Keyword(s):  
Electron Microscopy ◽  
Saccharomyces Cerevisiae ◽  
Scanning Electron Microscopy ◽  
Cell Wall ◽  
Candida Albicans ◽  
Cell Walls ◽  
Wall Structure ◽  
Before And After ◽  
Enzymatic Changes ◽  
Scanning Electron

Candida albicans and Saccharomyces cerevisiae cells were examined by scanning electron microscopy before and after extraction of the mannans of the cell wall. The surfaces of control cells were smooth; after mannan extraction they were rough and showed erosions which were particularly striking within the area of the scars. Helicase digested irregular holes through the cell wall within 20 min; these increased in size during an additional 40 min of digestion. These holes were not localized in or on the bud scars, which remained intact even after the long digestion period. The results were used to construct a model for yeast cell wall structure.

A comparison of the effects of several antifungal imidazole derivatives and polyenes on Candida albicans: an ultrastructural study by scanning electron microscopy

1982 ◽  
Vol 28 (10) ◽  
pp. 1119-1126 ◽  
Author(s):  
M. Bastide ◽  
S. Jouvert ◽  
J.-M. Bastide
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Candida Albicans ◽  
Cytoplasmic Membrane ◽  
Electron Microscopic Examination ◽  
Yeast Cells ◽  
Electron Microscopic ◽  
Imidazole Derivatives ◽  
Scanning Electron Microscopic ◽  
Scanning Electron

The early events in the interaction of two polyene (amphotericin B and nystatin) and five imidazole (clotrimazole, ketoconazole, miconazole, isoconazole, and econazole) antimycotics used at fungicidal concentrations with the surface of Candida albicans were studied by scanning electron microscopic examination of treated intact young yeast cells, treated spheroplasts, and spheroplasts liberated from treated young yeast cells. In all cases, treatment lasted 2 h. The polyenes passed through the yeast cell wall and interacted with the cytoplasmic membrane causing the spheroplasts to lose their characteristic spheric form and to liberate their contents. Clotrimazole caused the formation of numerous circular openings in the cytoplasmic membrane, but only when the agent was used to treat spheroplasts directly. Ketoconazole, miconazole, isoconazole, and econazole interacted with the cell wall causing formation of convolutions and wrinkles. The three imidazole derivatives that are structurally closely related, miconazole, isoconazole, and econazole, inhibited the enzyme-catalyzed release of spheroplasts from young yeast cells.

High-Resolution Field Emission Scanning Electron Microscopy (FESEM) Imaging of Cellulose Microfibril Organization in Plant Primary Cell Walls

2017 ◽  
Vol 23 (5) ◽  
pp. 1048-1054 ◽  
Author(s):  
Yunzhen Zheng ◽  
Daniel J. Cosgrove ◽  
Gang Ning
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Wall ◽  
High Resolution ◽  
Field Emission ◽  
Cell Walls ◽  
Cellulose Microfibrils ◽  
Critical Point Drying ◽  
Sputter Coating ◽  
Scanning Electron

AbstractWe have used field emission scanning electron microscopy (FESEM) to study the high-resolution organization of cellulose microfibrils in onion epidermal cell walls. We frequently found that conventional “rule of thumb” conditions for imaging of biological samples did not yield high-resolution images of cellulose organization and often resulted in artifacts or distortions of cell wall structure. Here we detail our method of one-step fixation and dehydration with 100% ethanol, followed by critical point drying, ultrathin iridium (Ir) sputter coating (3 s), and FESEM imaging at a moderate accelerating voltage (10 kV) with an In-lens detector. We compare results obtained with our improved protocol with images obtained with samples processed by conventional aldehyde fixation, graded dehydration, sputter coating with Au, Au/Pd, or carbon, and low-voltage FESEM imaging. The results demonstrated that our protocol is simpler, causes little artifact, and is more suitable for high-resolution imaging of cell wall cellulose microfibrils whereas such imaging is very challenging by conventional methods.

Digestion of cell-wall monosaccharides of ryegrass and alfalfa hays by the ruminal bacteria Fibrobacter succinogenes and Butyrivibrio fibrisolvens

1993 ◽  
Vol 39 (8) ◽  
pp. 780-786 ◽  
Author(s):  
Joshua Miron ◽  
Daniel Ben-Ghedalia
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Cell Walls ◽  
Surface Structures ◽  
Fibrobacter Succinogenes ◽  
Bacterial Cells ◽  
Ruminal Bacteria ◽  
Butyrivibrio Fibrisolvens ◽  
Scanning Electron ◽  
Better Than

The ruminal bacteria Fibrobacter succinogenes strains S85 and BL2 were grown in monocultures or in coculture with strain D1 of Butyrivibrio fibrisolvens, and the solubilization of ryegrass and alfalfa cell walls (CW) and digestion of CW monosaccharides were measured. Fibrobacter succinogenes monocultures and cocultures with B. fibrisolvens D1 degraded 58–69% of ryegrass CW, solubilizing 67–78% of CW glucose, 65–71% of CW xylose, 69–75% of hemicellulose, and 68–77% of total CW monosaccharides. When grown on alfalfa CW, those cultures degraded 28–39% of alfalfa CW, solubilizing 42–58% of CW glucose, 30–36% of CW xylose, and 37–45% of hemicellulose. With respect to both substrates, F. succinogenes strains solubilized CW carbohydrates better than did B. fibrisolvens D1. Complementary interaction between B. fibrisolvens D1 and the F. succinogenes strains was identified with respect to the utilization of some solubilized carbohydrates, but not with respect to the extent of CW solubilization, which was determined mainly by the F. succinogenes strains. For both substrates, utilization of solubilized cellulose by F. succinogenes monocultures was high (96–98%), whereas that of hemicellulose was lower (24–26% in ryegrass and 49–50% in alfalfa). Under scanning electron microscopy, F. succinogenes bacterial cells attached to and colonized on CW particles were characterized by the appearance of protuberant surface structures that we have identified as "polycellulosome complexes." Key words: cell wall monosaccharides, ryegrass, alfalfa, ruminal bacteria, Fibrobacter succinogenes, Butyrivibrio fibrisolvens.

Intercellular pectic strands in parenchyma: studies of plant cell walls by scanning electron microscopy.

1975 ◽  
Vol 23 (1) ◽  
pp. 95 ◽  
Author(s):  
SGM Carr ◽  
DJ Carr
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Wall ◽  
Chemical Composition ◽  
Light Microscope ◽  
Cell Walls ◽  
Plant Cell Walls ◽  
Intercellular Spaces ◽  
Mesophyll Cells ◽  
Scanning Electron

Rows of pectic strands, each 0.3-0.4�m in diameter, are shown to connect palisade mesophyll cells in regular ladder-like configurations ('pectic scala'). These structures are illustrated in some species of eucalypts, but probably occur in other kinds of plants. Less regular wall filaments can be observed in the intercellular spaces between other types of cells. They are particularly numerous in the parenchyma of species of ferns. These filaments and the pectic scala are readily observable by scanning electron microscopy, but can also be seen in conventional preparations for the light microscope. The structure, formation, chemical composition and possible function of these and other kinds of cell wall protuberances, described in the literature, are discussed.

Silicification of wood-cell walls

1994 ◽  
Vol 52 ◽  
pp. 428-429
Author(s):  
S. E. Keckler ◽  
D. M. Dabbs ◽  
N. Yao ◽  
I. A. Aksay
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Cell Walls ◽  
Lignin Content ◽  
Resin Composite ◽  
Middle Lamella ◽  
Cellulose Fibers ◽  
Complex Structures ◽  
Rich Region ◽  
Inorganic Precursors

Cellular organic structures such as wood can be used as scaffolds for the synthesis of complex structures of organic/ceramic nanocomposites. The wood cell is a fiber-reinforced resin composite of cellulose fibers in a lignin matrix. A single cell wall, containing several layers of different fiber orientations and lignin content, is separated from its neighboring wall by the middle lamella, a lignin-rich region. In order to achieve total mineralization, deposition on and in the cell wall must be achieved. Geological fossilization of wood occurs as permineralization (filling the void spaces with mineral) and petrifaction (mineralizing the cell wall as the organic component decays) through infiltration of wood with inorganics after growth. Conversely, living plants can incorporate inorganics into their cells and in some cases into the cell walls during growth. In a recent study, we mimicked geological fossilization by infiltrating inorganic precursors into wood cells in order to enhance the properties of wood. In the current work, we use electron microscopy to examine the structure of silica formed in the cell walls after infiltration of tetraethoxysilane (TEOS).

Some small-sized Cosmarium (Conjugatophyceae, Desmidiales) from sphagnum bogs of Moscow Region

2013 ◽  
Vol 47 ◽  
pp. 13-20
Author(s):  
O. V. Anissimova
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Wall ◽  
Moscow Region ◽  
Biological Station ◽  
Sphagnum Bogs ◽  
Different Seasons ◽  
Scanning Electron

Algae samples were collected during different seasons from 1997 to 2011 in two swamps located at Zvenigorod Biological Station in Moscow Region. There were found 25 Cosmarium species and varieties, 9 taxa of them being new to the region. Descriptions of the taxa were specified by observation of cell wall ornamentation with light and scanning electron microscopy. Original descriptions, photos and drawings of algae are presented.

Vergleich verschiedener Immun-Dekorationsmethoden für die Rasterelektronenmikroskopie am Beispiel eines Protein-Antigens auf der Oberfläche der Hefe Candida albicans/ A Comparison of Decoration Techniques for the Demonstration of Immunocomplexes by Scanning Electron Microscopy: Labeling of a Protein Antigen on the Surface of the Yeast Candida albicans

1985 ◽  
Vol 40 (7-8) ◽  
pp. 539-550 ◽  
Author(s):  
Margarete Borg
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Candida Albicans ◽  
Protein A ◽  
Peritoneal Macrophages ◽  
Polystyrene Latex ◽  
Target Antigen ◽  
Protein Antigens ◽  
Critical Point Drying ◽  
Scanning Electron

Abstract The labeling of immunocomplexes for scanning electron microscopy (SEM) is a fairly new technique, and the various procedures, that have been proposed, have not yet been compared. Such comparative evaluation was performed with Candida protease as a target antigen. This secretory enzyme of the opportunistic yeast Candida albicans can be localized on the surface of fungal blastopores and mycelia, both after growth in proteinaceous medium and upon infection of murine peritoneal macrophages. The presence of the protease antigen was confirmed by immunofluorescence and by immunoperoxidase-light microscopy. The decoration of protease - anti protease complexes for SEM was attempted with colloids derived from the immunoperoxidase reaction, by the immunogold technique, and by antibodies linked to beads of synthetic polymers (polystyrene, polymethacrylate, polyacrolein). In addition, inactivated Staphylococcus aureus was used, which binds to antibodies through its protein-A. The high resolution by SEM of surface structures was matched only by the colloid based decoration techniques. All conjugates with beads suffered from inconsistent binding, which did not correspond with the distribution of the surface antigen. The comparatively best result with beads was obtained with polystyrene (Latex). Colloid based techniques in addition allow for critical point drying, which cannot be applied to synthetic beads in the usual manner.

Actinomycetes in discolored wood of living silver maple

1981 ◽  
Vol 59 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Robert A. Blanchette ◽  
John B. Sutherland ◽  
Don L. Crawford
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Carbon Source ◽  
Cell Walls ◽  
Hydroxybenzoic Acid ◽  
Liquid Media ◽  
Streptomyces Strain ◽  
Culture Techniques ◽  
Silver Maple ◽  
Scanning Electron

The greenish-brown margin of discolored wood in three living silver maple trees, Acer saccharinum L., was examined by scanning electron microscopy and microbiological culture techniques. Micrographs of xylem vessels revealed filamentous structures; some of them appeared to be actinomycetous hyphae. Actinomycetes identified as Streptomyces parvullus Waksman & Gregory, S. sparsogenes Owen, Dietz & Camiener, and a third Streptomyces strain were isolated repeatedly from discolored wood of each tree. These isolates grew in liquid media in the presence of 0.1% (w/v) concentrations of several phenols. Although other phenols included in the test were not substantially degraded, p-hydroxybenzoic acid was utilized as a carbon source by S. parvullus. All three actinomycetes inhibited growth of selected wood-inhabiting fungi when paired on malt agar. When inoculated on sterilized sapwood and discolored wood from silver maple, the actinomycetes colonized vessel walls and occlusions, but were not observed to decay cell walls.

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