scholarly journals Structural Visualization of Septum Formation in Staphylococcus warneri Using Atomic Force Microscopy

2020 ◽  
Vol 202 (19) ◽  
Author(s):  
Hai-Nan Su ◽  
Kang Li ◽  
Long-Sheng Zhao ◽  
Xiao-Xue Yuan ◽  
Meng-Yao Zhang ◽  
...  
Keyword(s):  
Cell Division ◽  
Bacterial Cell ◽  
Structural Basis ◽  
Content Type ◽  
Cell Cycles ◽  
Force Microscopy ◽  
Staphylococcus Warneri ◽  
Septum Formation ◽  
Atomic Force ◽  
Inner Surface

ABSTRACT Cell division of Staphylococcus adopts a “popping” mechanism that mediates extremely rapid separation of the septum. Elucidating the structure of the septum is crucial for understanding this exceptional bacterial cell division mechanism. Here, the septum structure of Staphylococcus warneri was extensively characterized using high-speed time-lapse confocal microscopy, atomic force microscopy, and electron microscopy. The cells of S. warneri divide in a fast popping manner on a millisecond timescale. Our results show that the septum is composed of two separable layers, providing a structural basis for the ultrafast daughter cell separation. The septum is formed progressively toward the center with nonuniform thickness of the septal disk in radial directions. The peptidoglycan on the inner surface of double-layered septa is organized into concentric rings, which are generated along with septum formation. Moreover, this study signifies the importance of new septum formation in initiating new cell cycles. This work unravels the structural basis underlying the popping mechanism that drives S. warneri cell division and reveals a generic structure of the bacterial cell. IMPORTANCE This work shows that the septum of Staphylococcus warneri is composed of two layers and that the peptidoglycan on the inner surface of the double-layered septum is organized into concentric rings. Moreover, new cell cycles of S. warneri can be initiated before the previous cell cycle is complete. This work advances our knowledge about a basic structure of bacterial cell and provides information on the double-layered structure of the septum for bacteria that divide with the “popping” mechanism.

scholarly journals Structural visualization of septum formation in Staphylococcus warneri using atomic force microscopy

2020 ◽  
Author(s):  
Hai-Nan Su ◽  
Kang Li ◽  
Xiao-Xue Yuan ◽  
Meng-Yao Zhang ◽  
Si-Min Liu ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Cell Division ◽  
Bacterial Cell ◽  
Structural Basis ◽  
Cell Cycles ◽  
Force Microscopy ◽  
Staphylococcus Warneri ◽  
Septum Formation ◽  
Atomic Force ◽  
Inner Surface

ABSTRACTCell division of Staphylococcus adopts a “popping” mechanism that mediates extremely rapid separation of the septum. Elucidating the structure of the septum is crucial for understanding this exceptional bacterial cell division mechanism. Here, the septum structure of Staphylococcus warneri is extensively characterized using high-speed time-lapse confocal microscopy, atomic force microscopy, and electron microscopy. The cells of S. warneri divide in a fast “popping” manner on a millisecond timescale. Our results show that the septum is composed of two separable layers, providing a structural basis for the ultrafast daughter cell separation. The septum is formed progressively toward the center with non-uniform thickness of the septal disk in radial directions. The peptidoglycan on the inner surface of double-layered septa is organized into concentric rings, which are generated along with septum formation. Moreover, this study signifies the importance of new septum formation in initiating new cell cycles. This work unravels the structural basis underlying the “popping” mechanism that drives Staphylococcus cell division and reveals a generic structure of the bacterial cell.IMPORTRANCEThis work shows that the septum of Staphylococcus warneri is composed of two layers and the peptidoglycan on the inner surface of the double-layered septum is organized into concentric rings. Moreover, new cell cycles of Staphylococcus could be initiated before the previous cell cycle is complete. This work advances our knowledge about a basic structure of bacterial cell and provides the double layered structural information of septum for the bacterium that divide with the “popping” mechanism.

scholarly journals Dynamic Assembly/Disassembly of Staphylococcus aureus FtsZ Visualized by High-Speed Atomic Force Microscopy

2021 ◽  
Vol 22 (4) ◽  
pp. 1697
Author(s):  
Junso Fujita ◽  
Shogo Sugiyama ◽  
Haruna Terakado ◽  
Maho Miyazaki ◽  
Mayuki Ozawa ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Cell Division ◽  
Bacterial Cell ◽  
High Speed ◽  
Process Development ◽  
Imaging Techniques ◽  
Bacterial Cell Division ◽  
Force Microscopy ◽  
Atomic Force ◽  
Dynamic Assembly

FtsZ is a key protein in bacterial cell division and is assembled into filamentous architectures. FtsZ filaments are thought to regulate bacterial cell division and have been investigated using many types of imaging techniques such as atomic force microscopy (AFM), but the time scale of the method was too long to trace the filament formation process. Development of high-speed AFM enables us to achieve sub-second time resolution and visualize the formation and dissociation process of FtsZ filaments. The analysis of the growth and dissociation rates of the C-terminal truncated FtsZ (FtsZt) filaments indicate the net growth and dissociation of FtsZt filaments in the growth and dissociation conditions, respectively. We also analyzed the curvatures of the full-length FtsZ (FtsZf) and FtsZt filaments, and the comparative analysis indicated the straight-shape preference of the FtsZt filaments than those of FtsZf. These findings provide insights into the fundamental dynamic behavior of FtsZ protofilaments and bacterial cell division.

Corrosion inhibition behavior of four benzimidazole derivatives and benzotriazole on copper surface

2020 ◽  
Vol 67 (6) ◽  
pp. 565-574
Author(s):  
Lin Liu ◽  
Shuang Lu ◽  
Ya Qi Wu ◽  
Jin Yin Xie ◽  
Jinjuan Xing
Keyword(s):  
Electrochemical Measurement ◽  
Copper Surface ◽  
Molar Ratio ◽  
Benzimidazole Derivatives ◽  
Content Type ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Atomic Force ◽  
Mixture Concentration ◽  
Contact Angle Measurements

Purpose This paper aims to reduce environment pollution caused by benzotriazole. The authors chose one of the best inhibitors from 2-aminobenzimidazole, 2-methylbenzimidazol, 2-mercaptobenzimidazole and benzimidazole in combination with benzotriazole. Design/methodology/approach The electrochemical measurement indicated that 2-methylbenzimidazol had the best inhibition behavior. Then, it was mixed with benzotriazole. Techniques such as field emission scanning electron microscopy, atomic force microscopy, Raman spectroscopy and optical contact angle measurements were used. Findings The results showed that the inhibition efficiency was up to 99.98%, when the mixture concentration was 20 mmol/L and the molar ratio 1:1. Originality/value 1-benzotriazole was mixed with 2-methylbenzimidazol for the first time. During the exist of methyl, 2-methylbenzimidazol has the better inhibition; this point was ignored by researchers. Graphical abstract

scholarly journals Examining Bacterial Cell Interactions using Atomic Force Microscopy

2015 ◽  
Vol 108 (2) ◽  
pp. 633a
Author(s):  
Ronald Aucapina ◽  
Nadia Ouedraogo ◽  
Megan A. Ferguson
Keyword(s):  
Atomic Force Microscopy ◽  
Bacterial Cell ◽  
Cell Interactions ◽  
Force Microscopy ◽  
Atomic Force

scholarly journals MinC, MinD, and MinE Drive Counter-oscillation of Early-Cell-Division Proteins Prior to Escherichia coli Septum Formation

mBio ◽  
2013 ◽  
Vol 4 (6) ◽  
Author(s):  
Paola Bisicchia ◽  
Senthil Arumugam ◽  
Petra Schwille ◽  
David Sherratt
Keyword(s):  
Escherichia Coli ◽  
Cell Division ◽  
Lipid Bilayers ◽  
Epifluorescence Microscopy ◽  
Bacterial Cell Division ◽  
Content Type ◽  
Septum Formation ◽  
Early Stages ◽  
Z Ring ◽  
High Concentrations

ABSTRACTBacterial cell division initiates with the formation of a ring-like structure at the cell center composed of the tubulin homolog FtsZ (the Z-ring), which acts as a scaffold for the assembly of the cell division complex, the divisome. Previous studies have suggested that the divisome is initially composed of FtsZ polymers stabilized by membrane anchors FtsA and ZipA, which then recruit the remaining division proteins. The MinCDE proteins prevent the formation of the Z-ring at poles by oscillating from pole to pole, thereby ensuring that the concentration of the Z-ring inhibitor, MinC, is lowest at the cell center. We show that prior to septum formation, the early-division proteins ZipA, ZapA, and ZapB, along with FtsZ, assemble into complexes that counter-oscillate with respect to MinC, and with the same period. We propose that FtsZ molecules distal from high concentrations of MinC form relatively slowly diffusing filaments that are bound by ZapAB and targeted to the inner membrane by ZipA or FtsA. These complexes may facilitate the early stages of divisome assembly at midcell. As MinC oscillates toward these complexes, FtsZ oligomerization and bundling are inhibited, leading to shorter or monomeric FtsZ complexes, which become less visible by epifluorescence microscopy because of their rapid diffusion. Reconstitution of FtsZ-Min waves on lipid bilayers shows that FtsZ bundles partition away from high concentrations of MinC and that ZapA appears to protect FtsZ from MinC by inhibiting FtsZ turnover.IMPORTANCEA big issue in biology for the past 100 years has been that of how a cell finds its middle. InEscherichia coli, over 20 proteins assemble at the cell center at the time of division. We show that the MinCDE proteins, which prevent the formation of septa at the cell pole by inhibiting FtsZ, drive the counter-oscillation of early-cell-division proteins ZapA, ZapB, and ZipA, along with FtsZ. We propose that FtsZ forms filaments at the pole where the MinC concentration is the lowest and acts as a scaffold for binding of ZapA, ZapB, and ZipA: such complexes are disassembled by MinC and reform within the MinC oscillation period before accumulating at the cell center at the time of division. The ability of FtsZ to be targeted to the cell center in the form of oligomers bound by ZipA and ZapAB may facilitate the early stages of divisome assembly.

Localization, Assembly, and Activation of the Escherichia coli Cell Division Machinery

EcoSal Plus ◽  
2021 ◽  
Author(s):  
Petra Anne Levin ◽  
Anuradha Janakiraman
Keyword(s):  
Escherichia Coli ◽  
Cell Division ◽  
Bacterial Cell ◽  
Coli Cell ◽  
Bacterial Cell Division ◽  
Content Type ◽  
E Coli ◽  
Insight Into

Decades of research, much of it in Escherichia coli , have yielded a wealth of insight into bacterial cell division. Here, we provide an overview of the E. coli division machinery with an emphasis on recent findings.

Developing an electrochemical immunosensor for early diagnosis of hepatocellular carcinoma

Sensor Review ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Abdulrahman Al-Shami ◽  
Rami Joseph Oweis ◽  
Mohamed Ghazi Al-Fandi
Keyword(s):  
Hepatocellular Carcinoma ◽  
High Sensitivity ◽  
Differential Pulse ◽  
Electrochemical Immunosensor ◽  
Content Type ◽  
Force Microscopy ◽  
Promising Tool ◽  
Atomic Force ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Purpose This paper aims to report on the development of a novel electrochemical amperometric immunosensor to diagnose early hepatocellular carcinoma (HCC) by detecting the Midkine (MDK) biomarker. Design/methodology/approach Anti-Midkine antibodies were immobilized covalently through carbodiimides chemistry on carbon screen-printed electrodes modified with carboxylated multi-walled carbon nanotubes. The development process was characterized using cyclic voltammetry, electrochemical impedimetric spectroscopy, Fourier transform infrared spectroscopy and atomic force microscopy. Differential pulse voltammetry was used to investigate the immunosensor performance in detecting MDK antigen within the concentration range of 1 pg/ml to 100 ng/ml. Findings MDK immunosensor exhibited high sensitivity and linearity with a detection limit of 0.8 pg/ml and a correlation coefficient of 0.99. The biosensor also demonstrated high selectivity, stability and reproducibility. Originality/value The developed MDK immunosensor could be a promising tool to diagnose HCC and reduce the number of related deaths.

Grease thixotropy: evaluation of grease microstructure change due to shear and relaxation

2014 ◽  
Vol 66 (2) ◽  
pp. 223-237 ◽  
Author(s):  
Maciej Paszkowski ◽  
Sylwia Olsztyńska-Janus
Keyword(s):  
Qualitative Assessment ◽  
Structural Components ◽  
Lubricating Grease ◽  
Content Type ◽  
Base Oil ◽  
Force Microscopy ◽  
Atomic Force ◽  
Physicochemical Interactions ◽  
Lithium Soap ◽  
Mineral Base

Purpose – The thixotropy of lubricating grease thickened with lithium 12-hydroxystearate with mineral base oil was investigated. The thixotropy has a significant influence on the flow resistance and pressure drop in the structural components of lubrication systems, which is of major importance as today the latter are being centralized and automated. The paper aims to discuss these issues. Design/methodology/approach – Rheometer studies on thixotropy were carried out and the grease microstructure was visualized using atomic force microscopy (AFM). Total reflection Fourier transform infrared spectroscopy (ATR-FTIR) was used to study the physicochemical interactions which indicate the disintegration and recovery of the grease microstructure. Findings – A qualitative assessment of the physicochemical interactions between lithium soap floccules was made and a theory of the self-ordering effect of lithium 12-hydroxystearate associated molecules during shearing and their aggregation and flocculation during relaxation has been proposed. Originality/value – Because of the complexity of the disintegration and recovery of the lubricating grease thickener microstructure, there is still limited physical understanding of the mechanism of this process. Therefore, the present research was undertaken to identify the phenomena involved.

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