Periplasmic Space and Rigid Layer

2002 ◽  
pp. 103-132 ◽  
Author(s):  
Guntram Seltmann ◽  
Otto Holst
Keyword(s):  
Periplasmic Space ◽  
Rigid Layer

Microanatomy of the Periplasm of Bacillus Licheniformis

1971 ◽  
Vol 29 ◽  
pp. 262-263
Author(s):  
B.K. Ghosh
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Bacillus Licheniformis ◽  
External Environment ◽  
Permeability Barrier ◽  
Periplasmic Space ◽  
Modified Technique ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Periplasm of bacteria is the space outside the permeability barrier of plasma membrane but enclosed by the cell wall. The contents of this special milieu exterior could be regulated by the plasma membrane from the internal, and by the cell wall from the external environment of the cell. Unlike the gram-negative organism, the presence of this space in gram-positive bacteria is still controversial because it cannot be clearly demonstrated. We have shown the importance of some periplasmic bodies in the secretion of penicillinase from Bacillus licheniformis.In negatively stained specimens prepared by a modified technique (Figs. 1 and 2), periplasmic space (PS) contained two kinds of structures: (i) fibrils (F, 100 Å) running perpendicular to the cell wall from the protoplast and (ii) an array of vesicles of various sizes (V), which seem to have evaginated from the protoplast.

Ultrastructure of periplasmic bodies in gram-negative bacteria

1990 ◽  
Vol 48 (3) ◽  
pp. 640-641
Author(s):  
Xie Nianming ◽  
Ding Shaoqing ◽  
Wang Luping ◽  
Yuan Zenglin ◽  
Zhan Guolai ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Campylobacter Jejuni ◽  
Proteus Mirabilis ◽  
Shigella Flexneri ◽  
Morphological Description ◽  
Gram Negative Bacteria ◽  
Periplasmic Space ◽  
Clostridium Tetani ◽  
Gram Negative ◽  
Brucella Canis

Perhaps the data about periplasmic enzymes are obtained through biochemical methods but lack of morphological description. We have proved the existence of periplasmic bodies by electron microscope and described their ultrastructures. We hope this report may draw the attention of biochemists and mrophologists to collaborate on researches in periplasmic enzymes or periplasmic bodies with each other.One or more independent bodies may be seen in the periplasmic space between outer and inner membranes of Gram-negative bacteria, which we called periplasmic bodies. The periplasmic bodies have been found in seven species of bacteria at least, including the Pseudomonas aeroginosa. Shigella flexneri, Echerichia coli. Yersinia pestis, Campylobacter jejuni, Proteus mirabilis, Clostridium tetani. Vibrio cholerae and Brucella canis.

Partial Lack of N-Acetyl Substitution of Glucosamine in the Peptidoglycan of the Budding Phototrophic Rhodomicrobium vannielii

1987 ◽  
Vol 42 (11-12) ◽  
pp. 1165-1170 ◽  
Author(s):  
Uwe J. Jürgens ◽  
Baldur Rieth ◽  
Jürgen Weckesser ◽  
Crawford S. Dow ◽  
Wilfried A. König
Keyword(s):  
Fatty Acids ◽  
Content Analysis ◽  
Type Structure ◽  
Diaminopimelic Acid ◽  
Strain Atcc ◽  
Muramic Acid ◽  
Cross Linkage ◽  
Rigid Layer ◽  
Rhodomicrobium Vannielii

The rigid layer and peptidoglycan fractions from two strains (ATCC 17100 and Rm 5) of the budding phototrophic Rhodomicrobium vannielii were isolated. Rigid layers of both strains contain protein in addition to peptidoglycan. They were free of polysaccharides and fatty acids. The respective peptidoglycan fractions contain glucosamine, muramic acid, ʟ-and ᴅ-alanine, ᴅ-glutamic and meso-diaminopimelic acid in approximately equimolar ratios except for a signifi­ cant lower relative ᴅ-alanine content. Analysis of partial acid hydrolysates revealed A 1 γ-type structure of Rhodomicrobium vannielii peptidoglycan (shown with strain ATCC 17100). An about 10-30% lack of N-acetylation of glucosamine was indicated. The degree of cross-linkage was found to be about 60% . No differences in peptidoglycan composition and degree of cross-linkage were found between swarmer-and chain-cells as examined with strain Rm 5.

Stability of the Size-Dependent and Functionally Graded Curvilinear Timoshenko Beams

2017 ◽  
Vol 12 (4) ◽  
Author(s):  
J. Awrejcewicz ◽  
A. V. Krysko ◽  
S. P. Pavlov ◽  
M. V. Zhigalov ◽  
V. A. Krysko
Keyword(s):  
Differential Equations ◽  
Functionally Graded Material ◽  
Timoshenko Beam ◽  
Stability Loss ◽  
Functionally Graded ◽  
Beam Deflection ◽  
Timoshenko Beams ◽  
Size Dependent ◽  
Rigid Layer ◽  
Graded Material

The size-dependent model is studied based on the modified couple stress theory for the geometrically nonlinear curvilinear Timoshenko beam made from a functionally graded material having its properties changed along the beam thickness. The influence of the size-dependent coefficient and the material grading on the stability of the curvilinear beams is investigated with the use of the setup method. The second-order accuracy finite difference method is used to solve the problem of nonlinear partial differential equations (PDEs) by reducing it to the Cauchy problem. The obtained set of nonlinear ordinary differential equations (ODEs) is then solved by the fourth-order Runge–Kutta method. The relaxation method is employed to solve numerous static problems based on the dynamic approach. Eight different combinations of size-dependent coefficients and the functionally graded material coefficient are used to study the stress-strain responses of Timoshenko beams. Stability loss of the curvilinear Timoshenko beams is investigated using the Lyapunov criterion based on the estimation of the Lyapunov exponents. Beams with/without the size-dependent behavior, homogeneous beams, and functionally graded beams having the same stiffness are investigated. It is shown that in straight-line beams, the size-dependent effect decreases the beam deflection. The same is observed if the most rigid layer is located on the top of the beam. In the curvilinear Timoshenko beam, such a location of the most rigid layer essentially improves the beam strength against stability loss. The observed transition of the largest Lyapunov exponent from a negative to positive value corresponds to the transition from a precritical to postcritical beam state.

scholarly journals Author Correction: Disulfide-compatible phage-assisted continuous evolution in the periplasmic space

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mary S. Morrison ◽  
Tina Wang ◽  
Aditya Raguram ◽  
Colin Hemez ◽  
David R. Liu
Keyword(s):  
Periplasmic Space ◽  
Continuous Evolution

scholarly journals The sacrificial adaptor protein Skp functions to remove stalled substrates from the β-barrel assembly machine

2021 ◽  
Vol 119 (1) ◽  
pp. e2114997119
Author(s):  
Ashton N. Combs ◽  
Thomas J. Silhavy
Keyword(s):  
Molecular Chaperones ◽  
Outer Membrane Proteins ◽  
Adaptor Protein ◽  
Gram Negative Bacteria ◽  
Periplasmic Space ◽  
Timely Manner ◽  
Gram Negative ◽  
Bam Complex ◽  
Periplasmic Chaperone ◽  
Chaperone Network

The biogenesis of integral β-barrel outer membrane proteins (OMPs) in gram-negative bacteria requires transport by molecular chaperones across the aqueous periplasmic space. Owing in part to the extensive functional redundancy within the periplasmic chaperone network, specific roles for molecular chaperones in OMP quality control and assembly have remained largely elusive. Here, by deliberately perturbing the OMP assembly process through use of multiple folding-defective substrates, we have identified a role for the periplasmic chaperone Skp in ensuring efficient folding of OMPs by the β-barrel assembly machine (Bam) complex. We find that β-barrel substrates that fail to integrate into the membrane in a timely manner are removed from the Bam complex by Skp, thereby allowing for clearance of stalled Bam–OMP complexes. Following the displacement of OMPs from the assembly machinery, Skp subsequently serves as a sacrificial adaptor protein to directly facilitate the degradation of defective OMP substrates by the periplasmic protease DegP. We conclude that Skp acts to ensure efficient β-barrel folding by directly mediating the displacement and degradation of assembly-compromised OMP substrates from the Bam complex.

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