scholarly journals CORYNEBACTERIUM: FEATURES OF THE STRUCTURE OF THE BACTERIAL CELL

2017 ◽  
pp. 107-114
Author(s):  
G. G. Kharseeva ◽  
N. A. Voronina
Keyword(s):  
Cell Wall ◽  
Cytoplasmic Membrane ◽  
Molecular Genetic ◽  
Surface Proteins ◽  
Bacterial Cells ◽  
Closely Related Species ◽  
Wall Structures ◽  
Cord Factor ◽  
And Function ◽  
Structure And Functions

In a review of the features of the bacterial cells are Corynebacterium structure: characterized by an upper layer, highly organized cell wall, cytoplasmic membrane, cytoplasm, nucleoid. Described in detail the structure of the upper layer containing pili (fimbriae), microcapsule surface proteins - PS-2, DIP1281, 67-72r protein (hemagglutinin), porins, sialidase (neuraminidase). These components are the ability to initiate a serial of Corynebacterium work with the host cell, followed by colonization. It submitted a detailed description of the structure and functions of cell wall structures - cord factor, which is a second barrier permeability; arabinogalactan, peptidoglycan, lipomannan and lipoarabinomannan. The structure and function of the cytoplasmic membrane as the main diffusion barrier cell cytoplasm and the genome of Corynebacterium. Presented different molecular genetic methods for the identification and differentiation of closely related species of Corynebacterium.

Not Just a Simple Sugar: Arabinose Metabolism and Function in Plants

2021 ◽  
Author(s):  
Alban Mariette ◽  
Hee Sung Kang ◽  
Joshua L Heazlewood ◽  
Staffan Persson ◽  
Berit Ebert ◽  
...  
Keyword(s):  
Cell Wall ◽  
De Novo ◽  
Research Area ◽  
Land Plant ◽  
Future Research ◽  
Wall Structures ◽  
The Many ◽  
And Function ◽  
Simple Sugar ◽  
Development Structure

Abstract Growth, development, structure as well as dynamic adaptations and remodelling processes in plants are largely controlled by the properties of their cell walls. These intricate wall structures are mostly made up of different sugars connected through specific glycosidic linkages but also contain many glycosylated proteins. A key plant sugar that is present throughout the plantae, even before the divergence of the land plant lineage, but is not found in animals, is L-Arabinose (L-Ara). Here, we summarize and discuss the processes and proteins involved in L-Ara de novo synthesis, L-Ara interconversion, and the assembly and recycling of L-Ara-containing cell wall polymers and proteins. We also discuss the biological function of L-Ara in a context focused manner, mainly addressing cell wall related functions that are conferred by the basic physical properties of arabinose containing polymers/compounds. In this article we explore these processes with the goal of directing future research efforts to the many exciting yet unanswered questions in this research area.

scholarly journals Differential PilA pilus assembly by a hospital-acquired and a community-derived Enterococcus faecium isolate

Microbiology ◽  
2010 ◽  
Vol 156 (9) ◽  
pp. 2649-2659 ◽  
Author(s):  
Antoni P. A. Hendrickx ◽  
Claudia M. E. Schapendonk ◽  
Miranda van Luit-Asbroek ◽  
Marc J. M. Bonten ◽  
Willem van Schaik ◽  
...  
Keyword(s):  
Cell Wall ◽  
Gene Cluster ◽  
Enterococcus Faecium ◽  
Gene Clusters ◽  
Surface Proteins ◽  
Double Labelling ◽  
Bacterial Cells ◽  
Pilin Gene ◽  
Hospital Acquired ◽  
Pilus Assembly

Pili are hair-like structures protruding from the cell envelope of bacterial cells. Here, we describe the conditional and differential display of PilA-type pili, and PilE and PilF proteins, encoded from pilin gene cluster 1 at the surface of a hospital-acquired Enterococcus faecium bloodstream isolate (E1165) and a community-derived stool isolate (E1039), at two different temperatures. Both strains have virtually identical pilA gene clusters, as determined by sequencing. Western blotting and transmission immunoelectron microscopy revealed that PilA and PilF assembled into high-molecular-mass pilus-like structures at 37 °C in the E1165 strain, whereas PilE was not produced at either of the temperatures used; at 21 °C, PilA and PilF were cell-wall-anchored proteins. In contrast, in strain E1039, PilA, PilE and PilF pilin proteins were found to be displayed as cell-wall-anchored proteins at 37 °C only, and they were not associated with pilus-like structures. The discrepancy in pilus assembly between E1039 and E1165 cannot be explained by differences in expression of the genes encoding the predicted sortases in the pilA gene cluster, as these had similar expression levels in both strains at 21 and 37 °C. Double-labelling electron microscopy revealed that PilA formed the pilus backbone in E1165, and PilF the minor subunit which was distributed along the PilA pilus shaft and positioned at the tip; however, it was deposited as a cell-wall-anchored protein in a pilA isogenic mutant. The differential deposition of surface proteins from pilin gene cluster 1 and differences in pilus assembly in the two strains suggest a complex post-transcriptional regulatory mechanism of pilus biogenesis in E. faecium.

scholarly journals Multiple adhesin proteins on the cell surface of Streptococcus gordonii are involved in adhesion to human fibronectin

Microbiology ◽  
2009 ◽  
Vol 155 (11) ◽  
pp. 3572-3580 ◽  
Author(s):  
Nicholas S. Jakubovics ◽  
Jane L. Brittan ◽  
Lindsay C. Dutton ◽  
Howard F. Jenkinson
Keyword(s):  
Infective Endocarditis ◽  
Cell Surface ◽  
Molecular Genetic ◽  
Surface Proteins ◽  
Bacterial Cells ◽  
Streptococcus Gordonii ◽  
Human Fibronectin ◽  
Isogenic Mutants ◽  
Viridans Group Streptococci ◽  
Surface Adhesins

Adhesion of bacterial cells to fibronectin (FN) is thought to be a pivotal step in the pathogenesis of invasive infectious diseases. Viridans group streptococci such as Streptococcus gordonii are considered commensal members of the oral microflora, but are important pathogens in infective endocarditis. S. gordonii expresses a battery of cell-surface adhesins that act alone or in concert to bind host receptors. Here, we employed molecular genetic approaches to determine the relative contributions of five known S. gordonii surface proteins to adherence to human FN. Binding levels to FN by isogenic mutants lacking Hsa glycoprotein were reduced by 70 %, while mutants lacking CshA and CshB fibrillar proteins showed approximately 30 % reduced binding. By contrast, disruption of antigen I/II adhesin genes sspA and sspB in a wild-type background did not result in reduced FN binding. Enzymic removal of sialic acids from FN led to reduced S. gordonii DL1 adhesion (>50 %), but did not affect binding by the hsa mutant, indicating that Hsa interacts with sialic acid moieties on FN. Conversely, desialylation of FN did not affect adherence levels of Lactococcus lactis cells expressing SspA or SspB polypeptides. Complementation of the hsa mutant partially restored adhesion to FN. A model is proposed for FN binding by S. gordonii in which Hsa and CshA/CshB are primary adhesins, and SspA or SspB play secondary roles. Understanding the basis of oral streptococcal interactions with FN will provide a foundation for development of new strategies to control infective endocarditis.

Binding of mutagenic pyrolyzates to fractions of intestinal bacterial cells

1992 ◽  
Vol 38 (7) ◽  
pp. 614-617 ◽  
Author(s):  
Xue Bin Zhang ◽  
Yoshiyuki Ohta
Keyword(s):  
Escherichia Coli ◽  
Cell Wall ◽  
Outer Membrane ◽  
Bacterial Strain ◽  
Cytoplasmic Membrane ◽  
Intestinal Bacteria ◽  
Bacterial Cells ◽  
Gram Negative ◽  
Membrane Bound ◽  
Cell Fractions

The binding of mutagenic pyrolyzates to cell fractions from some gram-negative intestinal bacteria and to thermally treated bacterial cells was investigated. 3-Amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) and 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) were effectively bound by several of the bacterial cells. The cell wall skeletons of all bacteria effectively bound Trp-P-1 and Trp-P-2. Their cytoplasmic fractions retained Trp-P-1 and Trp-P-2, but to a lesser extent than the cell wall skeletons. 2-Amino-3-methylimidazo [4,5-f]quinoline (IQ) was not found in their cytoplasmic fractions. These cell wall skeletons also bound 2-amino-6-methyldipyrido[1,2-a:3′2′-d] imidazole (Glu-P-1), 2-amino-5-phenylpyridine (Phe-P-1), IQ, 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQX). The amount of each mutagen bound differed with the type of mutagen and the bacterial strain used. The outer membrane of Escherichia coli IFO 14249 showed binding of about 123.7 μg/mg of Trp-P-2, and its cytoplasmic membrane bound 57.14 μg/mg. Trp-P-2 bound to the bacterial cells was extracted with ammonia (5%), methanol, and ethanol but not with water. Key words: cell wall skeletons, outer membrane, cytoplasmic membrane, binding of mutagenic pyrolyzates.

scholarly journals Uncovering the activities, biological roles, and regulation of bacterial cell wall hydrolases and tailoring enzymes

2020 ◽  
Vol 295 (10) ◽  
pp. 3347-3361 ◽  
Author(s):  
Truc Do ◽  
Julia E. Page ◽  
Suzanne Walker
Keyword(s):  
Cell Wall ◽  
Bacterial Cell ◽  
Morphological Diversity ◽  
Basic Structure ◽  
Bacterial Cell Wall ◽  
Bacterial Cells ◽  
Mature Cell ◽  
Wall Structures ◽  
Peptidoglycan Hydrolases ◽  
Tailoring Enzymes

Bacteria account for 1000-fold more biomass than humans. They vary widely in shape and size. The morphological diversity of bacteria is due largely to the different peptidoglycan-based cell wall structures that encase bacterial cells. Although the basic structure of peptidoglycan is highly conserved, consisting of long glycan strands that are cross-linked by short peptide chains, the mature cell wall is chemically diverse. Peptidoglycan hydrolases and cell wall–tailoring enzymes that regulate glycan strand length, the degree of cross-linking, and the addition of other modifications to peptidoglycan are central in determining the final architecture of the bacterial cell wall. Historically, it has been difficult to biochemically characterize these enzymes that act on peptidoglycan because suitable peptidoglycan substrates were inaccessible. In this review, we discuss fundamental aspects of bacterial cell wall synthesis, describe the regulation and diverse biochemical and functional activities of peptidoglycan hydrolases, and highlight recently developed methods to make and label defined peptidoglycan substrates. We also review how access to these substrates has now enabled biochemical studies that deepen our understanding of how bacterial cell wall enzymes cooperate to build a mature cell wall. Such improved understanding is critical to the development of new antibiotics that disrupt cell wall biogenesis, a process essential to the survival of bacteria.

scholarly journals Nano-curcumin Capped Au/ZnO Nanocomposite: A Promising Approach to Protect from Staphylococcus Aureus Infection through Inhibits Production of α-Hemolysin

2021 ◽  
Author(s):  
Majid Jabir ◽  
Majid Jabir ◽  
Taha M. Rashid ◽  
Uday M. Nayef ◽  
Duha A. Kadhim
Keyword(s):  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Nucleic Acid ◽  
Antibacterial Agent ◽  
Cell Injury ◽  
Cytoplasmic Membrane ◽  
Alveolar Epithelial Cell ◽  
Diffusion Method ◽  
Bacterial Cells ◽  
Zno Nps

Abstract Gold with Zinc Oxide nanoparticles (Au@ZnO NPs) were prepared by laser ablation then capped with Curcumin nanoparticles. The ability of Nano-curcumin-Au/ZnO nanocomposite as a promising antibacterial agent was tested against Staphylococcus aureus. Cur-Au@ZnO NPs were characterized by TEM, FTIR spectroscopy, and Uv-spectroum. TEM image of Au@ZnO NPs has grain size almost 27–38 nm and it increased after capped Nano-curcumin to 72–113 nm. Agar well diffusion method was used to evaluate the antibacterial activity of Cur-Au@ZnO against S.aureus. The activity of Cur-Au@ZnO NPs was determined via detection of (ROS) using (AO/EtBr) staining assay. The bacterial cytoplasmic membrane and nucleic acid were penetrated by tested nanoparticles, resulting in bacterial strain destruction. The results showed that Cur-Au@ZnO NPs as a novel DNA-mediated antibacterial agent. The Cur-Au@ZnO were observed to destroy the bacterial cells by permeating the bacterial nucleic acid and cytoplasmic membrane, resulting in the loss of cell-wall integrity, nucleic acid damage, and increased cell-wall permeability. Furthermore, in the present study we investigated the activity of Cur-Au@ZnO NPs against bacterial α-Hemolysin toxin. Western blot were used to measure the effect of Cur-Au@ZnO NPs on α-Hemolysin produced by S. aureus. The effectiveness of Cur-Au@ZnO NPs against human alveolar epithelial cell injury by α-Hemolysin was tested using live ⁄ dead staining. Also, we demonstrated the role of Cur-Au@ZnO NPs against S. aureus through histopathology examination in a mouse model. Taken together, Cur-Au@ZnO NPs is a potent inhibitor of α-hemolysin secreted by S. aureus. So, Cur-Au@ZnO NPs mediated inhibition of α-Hemolysin production may offer a new strategy in combating pathogen infections. The Cur-Au@ZnO could serve as a potential antibacterial agent in future for biomedical and pharmaceutical applications.

Effect of piperacillin on morphology and viability of gram-negative bacteria

1984 ◽  
Vol 42 ◽  
pp. 218-219
Author(s):  
R. H. Liss
Keyword(s):  
Inhibitory Concentration ◽  
Cytoplasmic Membrane ◽  
Drug Binding ◽  
Gram Negative Bacteria ◽  
Bacterial Cells ◽  
Drug Induced ◽  
Penicillin Binding Proteins ◽  
Lactam Antibiotic ◽  
Drug Free ◽  
Tube Dilution

Piperacillip (PIP) is b-[D(-)-α-(4-ethy1-2,3-dioxo-l-piperzinylcar-bonylamino)-α-phenylacetamido]-penicillanate. The broad spectrum semisynthetic β-lactam antibiotic is believed to effect bactericidal activity through its affinity for penicillin-binding proteins (PBPs), enzymes on the bacterial cytoplasmic membrane that control elongation and septation during cell growth and division. The purpose of this study was to correlate penetration and binding of 14C-PIP in bacterial cells with drug-induced lethal changes assessed by microscopic, microbiologic and biochemical methods.The bacteria used were clinical isolates of Escherichia coli and Pseudomonas aeruginosa (Figure 1). Sensitivity to the drug was determined by serial tube dilution in Trypticase Soy Broth (BBL) at an inoculum of 104 organisms/ml; the minimum inhibitory concentration of piperacillin for both bacteria was 1 μg/ml. To assess drug binding to PBPs, the bacteria were incubated with 14C-PIP (5 μg/0.09 μCi/ml); controls, in drug-free medium.

Comparative surface and ultrastructural views of methylotrophic bacteria by TEM, STEM, SE, and freeze-etch electron microscopy.

1987 ◽  
Vol 45 ◽  
pp. 792-793
Author(s):  
T.A. Fassel ◽  
M.J. Schaller ◽  
M.E. Lidstrom ◽  
C.C. Remsen
Keyword(s):  
Cytoplasmic Membrane ◽  
Structural Features ◽  
Methylotrophic Bacteria ◽  
Type I ◽  
Type Ii ◽  
Membrane Complex ◽  
Oxidation Of Methane ◽  
Methane Oxidizing Bacteria ◽  
Wall Structures ◽  
Methylomonas Albus

Methylotrophic bacteria play an Important role in the environment in the oxidation of methane and methanol. Extensive intracytoplasmic membranes (ICM) have been associated with the oxidation processes in methylotrophs and chemolithotrophic bacteria. Classification on the basis of ICM arrangement distinguishes 2 types of methylotrophs. Bundles or vesicular stacks of ICM located away from the cytoplasmic membrane and extending into the cytoplasm are present in Type I methylotrophs. In Type II methylotrophs, the ICM form pairs of peripheral membranes located parallel to the cytoplasmic membrane. Complex cell wall structures of tightly packed cup-shaped subunits have been described in strains of marine and freshwater phototrophic sulfur bacteria and several strains of methane oxidizing bacteria. We examined the ultrastructure of the methylotrophs with particular view of the ICM and surface structural features, between representatives of the Type I Methylomonas albus (BG8), and Type II Methylosinus trichosporium (OB-36).

SEM and fluorescence imaging of callose deposition in root hair tips and suspension cultures of Streptanthus tortuosus

1990 ◽  
Vol 48 (3) ◽  
pp. 698-699
Author(s):  
K.S. Walters ◽  
R.D. Sjolund ◽  
K.C. Moore
Keyword(s):  
Cell Wall ◽  
Root Hair ◽  
Cultured Cells ◽  
Root Hairs ◽  
Callus Cultures ◽  
Callose Deposition ◽  
Culture Cells ◽  
Wall Structures ◽  
Ultraviolet Illumination ◽  
Callose Formation

Callose, B-1,3-glucan, a component of cell walls, is associated with phloem sieve plates, plasmodesmata, and other cell wall structures that are formed in response to wounding or infection. Callose reacts with aniline blue to form a fluorescent complex that can be recognized in the light microscope with ultraviolet illumination. We have identified callose in cell wall protuberances that are formed spontaneously in suspension-cultured cells of S. tortuosus and in the tips of root hairs formed in sterile callus cultures of S. tortuosus. Callose deposits in root hairs are restricted to root hair tips which appear to be damaged or deformed, while normal root hair tips lack callose deposits. The callose deposits found in suspension culture cells are restricted to regions where unusual outgrowths or protuberances are formed on the cell surfaces, specifically regions that are the sites of new cell wall formation.Callose formation has been shown to be regulated by intracellular calcium levels.

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