scholarly journals THE PRESENCE OF A GROUP A VARIANT-LIKE ANTIGEN IN STREPTOCOCCI OF OTHER GROUPS WITH SPECIAL REFERENCE TO GROUP N

1971 ◽  
Vol 133 (3) ◽  
pp. 479-493 ◽  
Author(s):  
S. D. Elliott ◽  
John Hayward ◽  
T. Y. Liu
Keyword(s):  
Cell Wall ◽  
Special Reference ◽  
Cell Walls ◽  
Cell Wall Structure ◽  
Wall Structure ◽  
Specific Polysaccharide ◽  
Group A ◽  
Unknown Composition ◽  
Group D ◽  
Serological Specificity

A Group A variant-like antigen has been detected in streptococci belonging to Groups D, E, G, M, and N. In Groups D and N the variant-like antigen was located in the streptococcal cell walls. In two strains of Group N streptococci (C559 and B209) the cell walls were chemically different and serologically distinct. In strain C559 N-acetylgalactosamine, and in strain B209, N-acetylglucosamine were the major determinants of serological specificity. The cell walls of strain C559 contained at least three serologically reactive components: a rhamnose-containing fraction that precipitated with an antiserum to Group A-variant carbohydrate; a strain-specific polysaccharide composed of galactosamine and glucosamine, both in the N-acetylated form and probably polymerized with an unidentified phosphorylated substance; and a component of unknown composition serologically related to a Group D streptococcus strain C3 (S. durans). An analogy is drawn between the cell wall structure in streptococcus and Salmonella.

scholarly journals Investigation of the Mechanical Properties of Flax Cell Walls during Plant Development: The Relation between Performance and Cell Wall Structure

Fibers ◽  
2018 ◽  
Vol 6 (1) ◽  
pp. 6 ◽  
Author(s):  
Camille Goudenhooft ◽  
David Siniscalco ◽  
Olivier Arnould ◽  
Alain Bourmaud ◽  
Olivier Sire ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cell Wall ◽  
Plant Development ◽  
Cell Walls ◽  
Cell Wall Structure ◽  
Wall Structure

scholarly journals Staphylococcus aureus cell wall structure and dynamics during host-pathogen interaction

2021 ◽  
Vol 17 (3) ◽  
pp. e1009468
Author(s):  
Joshua A. F. Sutton ◽  
Oliver T. Carnell ◽  
Lucia Lafage ◽  
Joe Gray ◽  
Jacob Biboy ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Cell Walls ◽  
Ex Vivo ◽  
Cell Wall Structure ◽  
Wall Structure ◽  
Bacterial Cells ◽  
Human Macrophages ◽  
Structure And Dynamics

Peptidoglycan is the major structural component of the Staphylococcus aureus cell wall, in which it maintains cellular integrity, is the interface with the host, and its synthesis is targeted by some of the most crucial antibiotics developed. Despite this importance, and the wealth of data from in vitro studies, we do not understand the structure and dynamics of peptidoglycan during infection. In this study we have developed methods to harvest bacteria from an active infection in order to purify cell walls for biochemical analysis ex vivo. Isolated ex vivo bacterial cells are smaller than those actively growing in vitro, with thickened cell walls and reduced peptidoglycan crosslinking, similar to that of stationary phase cells. These features suggested a role for specific peptidoglycan homeostatic mechanisms in disease. As S. aureus penicillin binding protein 4 (PBP4) has reduced peptidoglycan crosslinking in vitro its role during infection was established. Loss of PBP4 resulted in an increased recovery of S. aureus from the livers of infected mice, which correlated with enhanced fitness within murine and human macrophages. Thicker cell walls correlate with reduced activity of peptidoglycan hydrolases. S. aureus has a family of 4 putative glucosaminidases, that are collectively crucial for growth. Loss of the major enzyme SagB, led to attenuation during murine infection and reduced survival in human macrophages. However, loss of the other three enzymes Atl, SagA and ScaH resulted in clustering dependent attenuation, in a zebrafish embryo, but not a murine, model of infection. A combination of pbp4 and sagB deficiencies resulted in a restoration of parental virulence. Our results, demonstrate the importance of appropriate cell wall structure and dynamics during pathogenesis, providing new insight to the mechanisms of disease.

scholarly journals The Influence of Hydrolytic Enzymes on Tannin Adsorption-Desorption onto Grape Cell Walls in a Wine-Like Matrix

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 770
Author(s):  
Andrea Osete-Alcaraz ◽  
Encarna Gómez-Plaza ◽  
Pilar Martínez-Pérez ◽  
Florent Weiller ◽  
Julia Schückel ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Practical Importance ◽  
Hydrolytic Enzymes ◽  
Cell Wall Structure ◽  
Size Exclusion ◽  
Wall Structure ◽  
Cell Wall Polysaccharide ◽  
Desorption Process ◽  
Grape Cell

This study evaluates the capacity of four hydrolytic enzymes to limit the interactions between grape cell-walls and tannins and/or to favor tannin desorption. Adsorption and desorption tests were conducted by mixing a commercial seed tannin with purified skin cell-walls from Syrah grapes, in the presence or absence of hydrolytic enzymes, in a model-wine solution. The effects of the enzymes were evaluated by measuring the tannins in solution by High Performance Liquid Chromatography (HPLC) and the changes in the cell wall polysaccharide network by Comprehensive Microarray Polymer Profiling (COMPP) while the polysaccharides liberated from cell walls were analyzed by Size Exclusion Chromatography (SEC). The results showed that the enzymes limited the interaction between tannins and cell walls, especially cellulase, pectinase and xylanase, an effect associated with the cell wall structural modifications caused by the enzymes, which reduced their capacity to bind tannins. With regards to the tannin desorption process, enzymes did not play a significant role in liberating bound tannins. Those enzymes that showed the highest effect in limiting the adsorption of tannins and in disorganizing the cell wall structure, cellulase and pectinase, did not lead to a desorption of bound tannins, although they still showed a capacity of affecting cell wall structure. The results indicate that enzymes are not able to access those polysaccharides where tannins are bound, thus, they are not a useful tool for desorbing tannins from cell walls. The practical importance implications of these findings are discussed in the manuscript.

Role of streptomycin in the life of Streptomyces griseus: streptidine-containing fractions in the cell walls of Streptomyces griseus strains

1968 ◽  
Vol 14 (12) ◽  
pp. 1325-1331 ◽  
Author(s):  
Gy. Barabás ◽  
G. Szabó
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Streptomyces Griseus ◽  
Cell Wall Structure ◽  
Wall Structure

Streptidine was isolated from the cell wall and mycelia of a Streptomyces griseus strain that did not produce streptomycin. Streptidine probably exists as a complex with arginine and other Sakaguchi- and ninhydrin-positive compounds. Hydrolyzing these compounds with 6 N HCl for 20 hours released streptidine, arginine, threonine, serine, and alanine. A method is presented for the separation of streptidine from arginine.Streptidine was also found in the cell wall of a streptomycin-producing S. griseus strain. These facts support a hypothesis that streptidine plays a role in the cell wall structure of S. griseus.

scholarly journals Changes in cell wall structure during the protonema development on organic medium in conditions of light and darkness in Funaria hygrometrica

2015 ◽  
Vol 41 (1) ◽  
pp. 121-128 ◽  
Author(s):  
F. Młodzianowski ◽  
A. Woźny ◽  
A. Szweykowska
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Organic Medium ◽  
Cell Wall Structure ◽  
Wall Structure ◽  
Funaria Hygrometrica ◽  
Fibrillar Material ◽  
Prolonged Time ◽  
Cell Structures ◽  
Plasmalemma Invaginations

The cell walls of a protonema of <i>Funaria hygrometrica</i> cultivated in glucose containing medium were considerably thicker in dark than in light. After a prolonged time of dank culture, a considerable reduction of the wall thicknes was observed, simultaneously with the occurrence of vesicles and plasmalemma invaginations containing fibrillar material. It is suggested that in conditions unfavourable for growth, the sugar taken up from the medium can be accumulated in cell walls, from which it can be mobilized again in conditions of starvation. The authors also think that similar mechanism and cell structures can be involved in both building and decomposition of the cell wall.

HYPHAL CELL WALL STRUCTURE OF TWO SPECIES OF PYTHIUM

1966 ◽  
Vol 12 (3) ◽  
pp. 471-475 ◽  
Author(s):  
Ralph Mitchell ◽  
Naama Sabar
Keyword(s):  
Amino Acids ◽  
Cell Wall ◽  
Cell Walls ◽  
Cell Wall Structure ◽  
Wall Structure ◽  
Pythium Myriotylum ◽  
Hyphal Cell

Hyphal cell walls were prepared by ultrasonication. Glucose was the only sugar detected in both species. Evidence was obtained indicating that the Pythium butleri Subram. glucan is beta 1,2-linked, and that the glucan of Pythium myriotylum Drechsler is beta 1,4-linked. Sixteen amino acids were detected in P. butleri cell wall hydrolysates. Four of these amino acids were absent from P. myriotylum preparations. Similar quantities of lipid were found in both species. The significance of these data for fungal classification is discussed.

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