scholarly journals The Pseudomonas aeruginosa homeostasis enzyme AlgL clears the periplasmic space of accumulated alginate during polymer biosynthesis

2022 ◽  
pp. 101560
Author(s):  
Andreea A. Gheorghita ◽  
Francis Wolfram ◽  
Gregory B. Whitfield ◽  
Holly M. Jacobs ◽  
Roland Pfoh ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Periplasmic Space

Alkaline phosphatase of Pseudomonas aeruginosa: the mechanism of secretion and release of the enzyme from whole cells

1973 ◽  
Vol 19 (11) ◽  
pp. 1407-1415 ◽  
Author(s):  
J. M. Ingram ◽  
K. -J. Cheng ◽  
J. W. Costerton
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Alkaline Phosphatase ◽  
Cell Wall ◽  
Culture Filtrate ◽  
Outer Wall ◽  
Outer Cell ◽  
Periplasmic Space ◽  
Electron Microscopic ◽  
Whole Cells ◽  
Variable Quantity

The release of alkaline phosphatase from whole cells of Pseudomonas aeruginosa as a function of the MgCl2 concentration is proportional to the release of lipopolysaccharide from the cells. Cells grown under conditions where APase is almost completely secreted to the culture filtrate, i.e. growth at pH 7.6, also secrete lipopolysaccharide. Twenty percent sucrose releases a variable quantity of whole cell phosphatase. Localization of this portion of enzyme by biochemical and electron-microscopic techniques showed that it is located on the cell surface exterior to the outer tripartite layer. Phosphatase, which is not released by sucrose, but which is released by MgCl2, is located in the periplasmic space. Phosphatase is located in three areas; the culture filtrate, the outer cell wall surface, and the periplasmic space. The results suggest that A Pase is associated with, and bound to, a cell wall fraction which contains lipopolysaccharide and that the enzyme is "transported" through the outer wall in complex with this fraction. Liberation of the complex from the outer wall may be accomplished by the mechanical shearing forces developed during growth or during the sucrose suspension procedure.

Release of rhodanese from Pseudomonas aeruginosa by cold shock and its localization within the cell

1979 ◽  
Vol 25 (3) ◽  
pp. 340-351 ◽  
Author(s):  
R. W. Ryan ◽  
M. P. Gourlie ◽  
R. C. Tilton
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Alkaline Phosphatase ◽  
Outer Membrane ◽  
Electron Micrographs ◽  
Cold Shock ◽  
Cytoplasmic Membrane ◽  
Lactic Dehydrogenase ◽  
Periplasmic Space ◽  
Whole Cells ◽  
Periplasmic Enzyme

Whole cells of Pseudomonas aeruginosa possess rhodanese activity. The enzyme can be released by rapidly resuspending the cells in cold Tris–HCl buffer. Approximately 95% of the rhodanese activity is released by cold shock. Release of the enzyme can be inhibited either by preincubating the cells with Mg2+ or by incorporating Mg2+ into the shocking buffer. The effect of Mg2+ can be reversed by washing the cells twice with buffer prior to cold shock. While rhodanese can be released from P. aeruginosa by cold shock, lactic dehydrogenase, a cytoplasmic enzyme, remains within the cell. Diazo-7-amino-1,3-naphthalenedisulfonic acid, a compound which does not penetrate the cytoplasmic membrane, completely inactivated rhodanese and alkaline phosphatase, a periplasmic enzyme, whereas lactic dehydrogenase retained its full activity. These data suggest that rhodanese in P. aeruginosa, like alkaline phosphatase, is located distal to the cytoplasmic membrane in the periplasmic space. Electron micrographs also show that portions of the lipopolysaccharide outer membrane are shed from the cell during cold shock, while cells preincubated with Mg2+ did not release segments of their outer membrane.

scholarly journals Cryo-Transmission Electron Microscopy of Frozen-Hydrated Sections of Escherichia coli and Pseudomonas aeruginosa

2003 ◽  
Vol 185 (20) ◽  
pp. 6112-6118 ◽  
Author(s):  
Valério R. F. Matias ◽  
Ashraf Al-Amoudi ◽  
Jacques Dubochet ◽  
Terry J. Beveridge
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Genetic Material ◽  
Supporting Evidence ◽  
Periplasmic Space ◽  
High Pressure Freezing ◽  
Transmission Electron ◽  
K 12 ◽  
Peptidoglycan Layer

ABSTRACT High-pressure freezing of Escherichia coli K-12 and Pseudomonas aeruginosa PAO1 in the presence of cryoprotectants provided consistent vitrification of cells so that frozen-hydrated sections could be cut, providing ∼2-nm resolution of structure. The size and shape of the bacteria, as well as their surface and cytoplasmic constituents, were nicely preserved and compared well with other published high-resolution techniques. Cells possessed a rich cytoplasm containing a diffuse dispersion of ribosomes and genetic material. Close examination of cells revealed that the periplasmic space was compressed during cryosectioning, a finding which provided supporting evidence that this space is filled by a compressible gel. Since the outer membrane and peptidoglycan layer are bonded together via lipoproteins, the space between them (although still part of the periplasmic space) was not as compacted. Even when this cryosectioning compression was taken into account, there was still substantial variability in the width of the periplasmic space. It is possible that the protoplast has some capacity to float freely within the periplasm.

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.

Sign in / Sign up

Export Citation Format

Share Document