The outer layer of the cell envelope of Halobacterium halobium

1969 ◽  
Vol 47 (1) ◽  
pp. 71-74 ◽  
Author(s):  
Carolyn L. Marshall ◽  
A. J. Wicken ◽  
A. D. Brown
Keyword(s):  
Cell Wall ◽  
Chemical Analysis ◽  
Outer Layer ◽  
Bacterial Cell ◽  
Cell Walls ◽  
Cell Envelope ◽  
Halobacterium Halobium ◽  
A Cell ◽  
Bacterial Cell Walls

The outer layer of the cell envelope of Halobacterium halobium was isolated after suspending the envelope in either 1 M NaCl or 0.02 M MgCl2. Chemical analysis of the isolated, solubilized outer layer showed it to consist of protein or glycoprotein with about 3% RNA. No free or bound lipid was detected. No cytochromes were present in the outer layer. Components commonly associated with bacterial cell walls were absent.Chemical composition together with the marked instability of the outer layer in a slight ion deficit are not consistent with a function of this layer as a "cell wall" of the organism.

scholarly journals Sham, Sam, And Bacterial Communication

1997 ◽  
Vol 5 (8) ◽  
pp. 8-9
Author(s):  
Lee van Hook
Keyword(s):  
Cell Wall ◽  
Bacterial Cell ◽  
Cell Walls ◽  
Piezoelectric Crystal ◽  
Acoustic Microscope ◽  
Bacterial Communication ◽  
Bacterial Cell Walls ◽  
Scanning Acoustic Microscope

A scanning acoustic microscope (SAM) - a nanomicrophone using a piezoelectric crystal, may be used to examine bacterial colonies, not just materials specimens to detect phonons and listen to propagating microfractures.Since bacterial cell walls are rigid structures, they undergo mechanical distortions when channels open and dose. This causes them to squeak and pop, each channel having its own sound. Channels and receptor molecules are all of different sizes and shapes, and therefore deform the cell wall in unique ways. This means that each channel makes a unique (if faint) sound when it passes a molecule through itself and this activity can be delected, Transport rates of uptake and excretion for the various compounds car then be calculated trom the intensity of the sounds.

scholarly journals Enzymes and Mechanisms Employed by Tailed Bacteriophages to Breach the Bacterial Cell Barriers

Viruses ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 396 ◽  
Author(s):  
Sofia Fernandes ◽  
Carlos São-José
Keyword(s):  
Cell Wall ◽  
Host Cell ◽  
Bacterial Cell ◽  
Cell Envelope ◽  
Genetic Material ◽  
Cell Types ◽  
Virus Multiplication ◽  
Virus Particles ◽  
Bacterial Cell Envelope ◽  
A Cell

Monoderm bacteria possess a cell envelope made of a cytoplasmic membrane and a cell wall, whereas diderm bacteria have and extra lipid layer, the outer membrane, covering the cell wall. Both cell types can also produce extracellular protective coats composed of polymeric substances like, for example, polysaccharidic capsules. Many of these structures form a tight physical barrier impenetrable by phage virus particles. Tailed phages evolved strategies/functions to overcome the different layers of the bacterial cell envelope, first to deliver the genetic material to the host cell cytoplasm for virus multiplication, and then to release the virion offspring at the end of the reproductive cycle. There is however a major difference between these two crucial steps of the phage infection cycle: virus entry cannot compromise cell viability, whereas effective virion progeny release requires host cell lysis. Here we present an overview of the viral structures, key protein players and mechanisms underlying phage DNA entry to bacteria, and then escape of the newly-formed virus particles from infected hosts. Understanding the biological context and mode of action of the phage-derived enzymes that compromise the bacterial cell envelope may provide valuable information for their application as antimicrobials.

scholarly journals Bacterial Cell Wall-Induced Arthritis: Chemical Composition and Tissue Distribution of Four Lactobacillus Strains

2000 ◽  
Vol 68 (6) ◽  
pp. 3535-3540 ◽  
Author(s):  
Egle Šimelyte ◽  
Marja Rimpiläinen ◽  
Leena Lehtonen ◽  
Xiang Zhang ◽  
Paavo Toivanen
Keyword(s):  
Cell Wall ◽  
Bacterial Cell ◽  
Cell Walls ◽  
Lactobacillus Casei ◽  
Chemical Structure ◽  
Chronic Arthritis ◽  
Bacterial Cell Wall ◽  
Peptidoglycan Structure ◽  
Bacterial Cell Walls ◽  
Spleen And Lymph Nodes

ABSTRACT To study what determines the arthritogenicity of bacterial cell walls, cell wall-induced arthritis in the rat was applied, using four strains of Lactobacillus. Three of the strains used proved to induce chronic arthritis in the rat; all were Lactobacillus casei. The cell wall of Lactobacillus fermentum did not induce chronic arthritis. All arthritogenic bacterial cell walls had the same peptidoglycan structure, whereas that of L. fermentum was different. Likewise, all arthritogenic cell walls were resistant to lysozyme degradation, whereas the L. fermentum cell wall was lysozyme sensitive. Muramic acid was observed in the liver, spleen, and lymph nodes in considerably larger amounts after injection of an arthritogenicL. casei cell wall than following injection of a nonarthritogenic L. fermentum cell wall. The L. casei cell wall also persisted in the tissues longer than theL. fermentum cell wall. The present results, taken together with those published previously, underline the possibility that the chemical structure of peptidoglycan is important in determining the arthritogenicity of the bacterial cell wall.

scholarly journals Species-Specific Cell Wall Binding Affinity of the S-Layer Proteins of Mosquitocidal Bacterium Bacillus sphaericus C3-41

2009 ◽  
Vol 75 (12) ◽  
pp. 3891-3895 ◽  
Author(s):  
Jia Li ◽  
Xiaomin Hu ◽  
Jianpin Yan ◽  
Zhiming Yuan
Keyword(s):  
Amino Acids ◽  
Cell Wall ◽  
Bacterial Cell ◽  
Cell Walls ◽  
Specific Binding ◽  
Distinct Type ◽  
Bacillus Sphaericus ◽  
Specific Cell ◽  
Bacterial Cell Walls ◽  
Species Specific

ABSTRACT The binding affinities and specificities of six truncated S-layer homology domain (SLH) polypeptides of mosquitocidal Bacillus sphaericus strain C3-41 with the purified cell wall sacculi have been assayed. The results indicated that the SLH polypeptide comprised of amino acids 31 to 210 was responsible for anchoring the S-layer subunits to the rigid cell wall layer via a distinct type of secondary cell wall polymer and that a motif of the recombinant SLH polypeptide comprising amino acids 152 to 210 (rSLH152-210) was essential for the stable binding of the S-layer with the bacterial cell walls. The quantitative assays revealed that the KD (equilibrium dissociation constant) values of rSLH152-210 and rSLH31-210 with purified cell wall sacculi were 1.11 × 10−6 M and 1.40 × 10−6 M, respectively. The qualitative assays demonstrated that the SLH domain of strain C3-41 could bind only to the cell walls or the cells treated with 5 M guanidinium hydrochloride of both toxic and nontoxic B. sphaericus strains but not to those from other bacteria, indicating the species-specific binding of the SLH polypeptide of B. sphaericus with bacterial cell walls.

Factors affecting the susceptibility of bacterial cell walls to the action of lysozyme

1967 ◽  
Vol 167 (1009) ◽  
pp. 446-447 ◽  
Keyword(s):  
Cell Wall ◽  
Bacterial Cell ◽  
Mode Of Action ◽  
Cell Walls ◽  
Bacterial Species ◽  
Bacterial Cell Wall ◽  
Low Molecular Weight ◽  
Factors Affecting ◽  
Structural Differences ◽  
Bacterial Cell Walls

Although we have heard a lot about the mode of binding of low molecular weight, soluble, lysozyme substrates, we have heard little about the mode of action of lysozyme on its natural insoluble substrate, the bacterial cell wall; so I want to bring a biological flavour into this discussion. Lysozyme was the name given by Fleming (1922) to the powerful bacteriolytic agent found in various cells and secretions; it was particularly active against a new bacterial species which he named Micrococcus lysodeikticus . The walls of this species still provide us with one of the best substrates for the study of lysozyme action. Salton showed that there is a considerable spectrum of activity of lysozyme in solubilizing walls of other species of bacteria. For example, walls of M. lysodeikticus are attacked rapidly by a concentration of enzyme of 1 μg/ml., Bacillus megaterium walls need 50 μg/ml., while walls of B. cereus are hardly changed visibly by 50 μg/ml. Consideration of the structure of the basal mucopeptide unit of bacterial cell walls, illustrated by Dr Perkins, shows that there are many ways in which structural differences could be introduced. Knowledge of the effects of some of these differences on lysozyme sensitivity may help in elucidating the mode of action of lysozyme on the complete bacterial cell wall.

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