scholarly journals THE DEMONSTRATION OF THE SUCCINIC DEHYDROGENASE SYSTEM IN BACILLUS SUBTILIS USING TETRANITRO-BLUE TETRAZOLIUM COMBINED WITH TECHNIQUES OF ELECTRON MICROSCOPY

1965 ◽  
Vol 27 (1) ◽  
pp. 53-66 ◽  
Author(s):  
Albert W. Sedar ◽  
Ronald M. Burde
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Bacillus Subtilis ◽  
Plasma Membrane ◽  
Enzymatic Activity ◽  
Cytoplasmic Membrane ◽  
Succinic Dehydrogenase ◽  
Nuclear Area ◽  
Blue Tetrazolium ◽  
Dehydrogenase System

Activity of the succinic dehydrogenase system was studied in Bacillus subtilis utilizing combined techniques of cytochemistry and electron microscopy. Organisms were incubated in a medium containing tetranitro-blue tetrazolium (TNBT) which served as an electron acceptor. Enzymatic activity, as evidenced by deposition of TNBT-formazan, was found on membranous organelles associated with the cytoplasmic membrane and septal plasma membrane, the nuclear area, and the plasma membrane. Flagella, ∼190 A in diameter, with thorn-like projections protruded through the cell wall. Tangential-oblique sections of the cell wall showed many pores ∼220 A in diameter with a center-to-center spacing of ∼450 A.

scholarly journals LOCALIZATION OF THE SUCCINIC DEHYDROGENASE SYSTEM IN ESCHERICHIA COLI USING COMBINED TECHNIQUES OF CYTOCHEMISTRY AND ELECTRON MICROSCOPY

1965 ◽  
Vol 24 (2) ◽  
pp. 285-295 ◽  
Author(s):  
Albert W. Sedar ◽  
Ronald M. Burde
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Plasma Membrane ◽  
Enzymatic Activity ◽  
Electron Acceptor ◽  
Succinic Dehydrogenase ◽  
Blue Tetrazolium ◽  
Dehydrogenase System

The activity of the succinic dehydrogenase system was studied in Escherichia coli utilizing combined techniques of cytochemistry and electron microscopy. Organisms were incubated in a medium containing tetranitro-blue tetrazolium (TNBT) which served as an electron acceptor. Enzymatic activity, as evidenced by the deposition of aggregates of TNBT-formazan, was found associated with the site of the plasma membrane of the bacterium.

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.

Ultrastructure of a marine psychrophilic Vibrio

1970 ◽  
Vol 16 (11) ◽  
pp. 1027-1031 ◽  
Author(s):  
S. F. Kennedy ◽  
R. R. Colwell ◽  
G. B. Chapman
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Plasma Membrane ◽  
Cell Division ◽  
Wall Material ◽  
Cross Wall ◽  
Growth Stages ◽  
Culture Age ◽  
Primary Mechanism ◽  
Age Studies

The structure of Vibrio marinus strain PS-207 was studied by both phase and electron microscopy. It was found to possess a trilaminar plasma membrane and cell wall. Membrane-bounded subunits containing DNA-like material were found dispersed throughout the cytoplasm. Giant round forms or "macrospheres" were observed in all growth stages. The size, shape, and construction of the "macrospheres" showed some variation, but could not be related to culture age. Studies of cell division in V. marinus strain PS-207 indicate the primary mechanism to be a synthesis and centripetal deposition of plasma membrane with a concomitant or subsequent synthesis and centripetal deposition of cross wall material.

Contractile elements of Lemna trisulca L. glycerinated cell models during chloroplast translocations

2000 ◽  
Vol 78 (4) ◽  
pp. 503-510
Author(s):  
Robert A Rinaldi ◽  
Barbara Kalisz-Nowak ◽  
Wlodzimierz Korohoda ◽  
Stanislaw Wieckowski ◽  
Wincenty Kilarski ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Plasma Membrane ◽  
Contractile Element ◽  
Cell Models ◽  
Chloroplast Membranes ◽  
Chloroplast Membrane ◽  
Membrane Cell

Electron microscopy of Lemna glycerinated cell models depicts contractile elements during chloroplast translocations. One contractile element, the thin ectoplasmic layer, is [Formula: see text] 0.4 µm thick, pressed against plasma membrane-cell wall. Thin ectoplasmic layer contains numerous oriented filaments and some appear to be actin and myosin. Another contractile element is the outer chloroplast membrane which envelops each chloroplast and joins or fuses with the thin ectoplasmic layer. Choroplast interconnections are formed between two or more chloroplasts by outer chloroplast membranes; they enhance chloroplast communications, translocations, and molecular exchanges.Key words: chloroplast translocations, contractility, tubular connections.

Enlarged Crystalline Patches on the Plasma Membrane of Yeast Protoplasts

1980 ◽  
Vol 38 ◽  
pp. 686-687
Author(s):  
G. Sosinsky ◽  
R. Schekman ◽  
R. Glaeser
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Plasma Membrane ◽  
High Resolution Electron Microscopy ◽  
Yeast Cells ◽  
Physiological Conditions ◽  
Resolution Electron ◽  
Yeast Protoplasts ◽  
Intramembraneous Particles ◽  
Crystalline Array

The crystalline patches of intramembraneous particles that form in the yeast plasma membrane, under stationary state physiological conditions, represent a potentially interesting specimen for high resolution electron microscopy. Isolation of these crystalline membrane patches first requires removal of the cell wall and the formation of osmotically fragile yeast protoplasts. In developing a procedure for the isolation of these crystalline membrane patches, we have found that the intramembraneous particles form much larger crystalline patches in protoplasts than in intact yeast cells. We have performed deep etch experiments and have found that the crystalline array of particles is not expressed on the extracellular surface of the plasma membrane.

scholarly journals Optimization of the Cell Wall Microenvironment Allows Increased Production of Recombinant Bacillus anthracis Protective Antigen from B. subtilis

2002 ◽  
Vol 68 (1) ◽  
pp. 227-234 ◽  
Author(s):  
Joanne E. Thwaite ◽  
Les W. J. Baillie ◽  
Noel M. Carter ◽  
Keith Stephenson ◽  
Mark Rees ◽  
...  
Keyword(s):  
Cell Wall ◽  
Bacillus Subtilis ◽  
Cytoplasmic Membrane ◽  
Protective Antigen ◽  
Teichoic Acid ◽  
Heterologous Proteins ◽  
Native Conformation ◽  
Anionic Polymer ◽  
Before And After ◽  
The Stability

ABSTRACT The stability of heterologous proteins secreted by gram-positive bacteria is greatly influenced by the microenvironment on the trans side of the cytoplasmic membrane, and secreted heterologous proteins are susceptible to rapid degradation by host cell proteases. In Bacillus subtilis, degradation occurs either as the proteins emerge from the presecretory translocase and prior to folding into their native conformation or after the native conformation has been reached. The former process generally involves membrane- and/or cell wall-bound proteases, while the latter involves proteases that are released into the culture medium. The identification and manipulation of factors that influence the folding of heterologous proteins has the potential to improve the yield of secreted heterologous proteins. Recombinant anthrax protective antigen (rPA) has been used as a model secreted heterologous protein because it is sensitive to proteolytic degradation both before and after folding into its native conformation. This paper describes the influence of the microenvironment on the trans side of the cytoplasmic membrane on the stability of rPA. Specifically, we have determined the influence of net cell wall charge and its modulation by the extent to which the anionic polymer teichoic acid is d-alanylated on the secretion and stability of rPA. The potential role of the dlt operon, responsible for d-alanylation, was investigated using a Bacillus subtilis strain encoding an inducible dlt operon. We show that, in the absence of d-alanylation, the yield of secreted rPA is increased 2.5-fold. The function of d-alanylation and the use of rPA as a model protein are evaluated with respect to the optimization of B. subtilis for the secretion of heterologous proteins.

scholarly journals d-Alanine Substitution of Teichoic Acids as a Modulator of Protein Folding and Stability at the Cytoplasmic Membrane/Cell Wall Interface of Bacillus subtilis

2000 ◽  
Vol 275 (35) ◽  
pp. 26696-26703 ◽  
Author(s):  
Hanne-Leena Hyyryläinen ◽  
Marika Vitikainen ◽  
Joanne Thwaite ◽  
Hongyan Wu ◽  
Matti Sarvas ◽  
...  
Keyword(s):  
Cell Wall ◽  
Protein Folding ◽  
Bacillus Subtilis ◽  
Cytoplasmic Membrane ◽  
Alanine Substitution ◽  
Teichoic Acids ◽  
Membrane Cell
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