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Jin E, Lv Z, Zhu Y, Zhang H, Li H. Nature-Inspired Micro/Nano-Structured Antibacterial Surfaces. Molecules 2024; 29:1906. [PMID: 38731407 PMCID: PMC11085384 DOI: 10.3390/molecules29091906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 04/18/2024] [Accepted: 04/19/2024] [Indexed: 05/13/2024] Open
Abstract
The problem of bacterial resistance has become more and more common with improvements in health care. Worryingly, the misuse of antibiotics leads to an increase in bacterial multidrug resistance and the development of new antibiotics has virtually stalled. These challenges have prompted the need to combat bacterial infections with the use of radically different approaches. Taking lessons from the exciting properties of micro-/nano-natural-patterned surfaces, which can destroy cellular integrity, the construction of artificial surfaces to mimic natural functions provides new opportunities for the innovation and development of biomedicine. Due to the diversity of natural surfaces, functional surfaces inspired by natural surfaces have a wide range of applications in healthcare. Nature-inspired surface structures have emerged as an effective and durable strategy to prevent bacterial infection, opening a new way to alleviate the problem of bacterial drug resistance. The present situation of bactericidal and antifouling surfaces with natural and biomimetic micro-/nano-structures is briefly reviewed. In addition, these innovative nature-inspired methods are used to manufacture a variety of artificial surfaces to achieve extraordinary antibacterial properties. In particular, the physical antibacterial effect of nature-inspired surfaces and the functional mechanisms of chemical groups, small molecules, and ions are discussed, as well as the wide current and future applications of artificial biomimetic micro-/nano-surfaces. Current challenges and future development directions are also discussed at the end. In the future, controlling the use of micro-/nano-structures and their subsequent functions will lead to biomimetic surfaces offering great potential applications in biomedicine.
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Affiliation(s)
| | | | | | | | - He Li
- School of Mechanical and Electrical Engineering, Henan Agricultural University, Zhengzhou 450002, China; (E.J.); (Z.L.); (Y.Z.); (H.Z.)
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2
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Valiei A, Bryche JF, Canva M, Charette PG, Moraes C, Hill RJ, Tufenkji N. Effects of Surface Topography and Cellular Biomechanics on Nanopillar-Induced Bactericidal Activity. ACS APPLIED MATERIALS & INTERFACES 2024; 16:9614-9625. [PMID: 38378485 DOI: 10.1021/acsami.3c09552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Bacteria are mechanically resistant biological structures that can sustain physical stress. Experimental data, however, have shown that high-aspect-ratio nanopillars deform bacterial cells upon contact. If the deformation is sufficiently large, it lyses the bacterial cell wall, ultimately leading to cell death. This has prompted a novel strategy, known as mechano-bactericide technology, to fabricate antibacterial surfaces. Although adhesion forces were originally proposed as the driving force for mechano-bactericidal action, it has been recently shown that external forces, such as capillary forces arising from an air-water interface at bacterial surfaces, produce sufficient loads to rapidly kill bacteria on nanopillars. This discovery highlights the need to theoretically examine how bacteria respond to external loads and to ascertain the key factors. In this study, we developed a finite element model approximating bacteria as elastic shells filled with cytoplasmic fluid brought into contact with an individual nanopillar or nanopillar array. This model elucidates that bacterial killing caused by external forces on nanopillars is influenced by surface topography and cell biomechanical variables, including the density and arrangement of nanopillars, in addition to the cell wall thickness and elastic modulus. Considering that surface topography is an important design parameter, we performed experiments using nanopillar arrays with precisely controlled nanopillar diameters and spacing. Consistent with model predictions, these demonstrate that nanopillars with a larger spacing increase bacterial susceptibility to mechanical puncture. The results provide salient insights into mechano-bactericidal activity and identify key design parameters for implementing this technology.
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Affiliation(s)
- Amin Valiei
- Department of Chemical Engineering, McGill University, Montreal, Québec H3A 0C5, Canada
| | - Jean-François Bryche
- Laboratoire Nanotechnologies Nanosystèmes (LN2)-IRL3463, CNRS, Université de Sherbrooke, Universitè Grenoble Alpes, École Centrale de Lyon, INSA Lyon, Sherbrooke, Québec J1K 0A5, Canada
- Institut Interdisciplinaire d'Innovation Technologique (3IT), Université de Sherbrooke, 3000 Boulevard de l'Université, Sherbrooke, Québec J1K OA5, Canada
| | - Michael Canva
- Laboratoire Nanotechnologies Nanosystèmes (LN2)-IRL3463, CNRS, Université de Sherbrooke, Universitè Grenoble Alpes, École Centrale de Lyon, INSA Lyon, Sherbrooke, Québec J1K 0A5, Canada
- Institut Interdisciplinaire d'Innovation Technologique (3IT), Université de Sherbrooke, 3000 Boulevard de l'Université, Sherbrooke, Québec J1K OA5, Canada
| | - Paul G Charette
- Laboratoire Nanotechnologies Nanosystèmes (LN2)-IRL3463, CNRS, Université de Sherbrooke, Universitè Grenoble Alpes, École Centrale de Lyon, INSA Lyon, Sherbrooke, Québec J1K 0A5, Canada
- Institut Interdisciplinaire d'Innovation Technologique (3IT), Université de Sherbrooke, 3000 Boulevard de l'Université, Sherbrooke, Québec J1K OA5, Canada
| | - Christopher Moraes
- Department of Chemical Engineering, McGill University, Montreal, Québec H3A 0C5, Canada
- Department of Biomedical Engineering, McGill University, Montreal, Québec H3A 0C5, Canada
- Goodman Cancer Research Center, McGill University, Montreal, Québec H3A 0G4, Canada
| | - Reghan J Hill
- Department of Chemical Engineering, McGill University, Montreal, Québec H3A 0C5, Canada
| | - Nathalie Tufenkji
- Department of Chemical Engineering, McGill University, Montreal, Québec H3A 0C5, Canada
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3
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Faluweki MK, Goehring L. Structural mechanics of filamentous cyanobacteria. J R Soc Interface 2022; 19:20220268. [PMID: 35892203 PMCID: PMC9326267 DOI: 10.1098/rsif.2022.0268] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 07/05/2022] [Indexed: 06/15/2023] Open
Abstract
Filamentous cyanobacteria, forming long strands of connected cells, are one of the earliest and most successful forms of life on Earth. They exhibit self-organized behaviour, forming large-scale patterns in structures like biomats and stromatolites. The mechanical properties of these rigid structures have contributed to their biological success and are important to applications like algae-based biofuel production. For active polymers like these cyanobacteria, one of the most important mechanical properties is the bending modulus, or flexural rigidity. Here, we quantify the bending stiffness of three species of filamentous cyanobacteria, of order Oscillatoriales, using a microfluidic flow device where single filaments are deflected by fluid flow. This is complemented by measurements of Young's modulus of the cell wall, via nanoindentation, and the cell wall thickness. We find that the stiffness of the cyanobacteria is well-captured by a simple model of a flexible rod, with most stress carried by a rigid outer wall. Finally, we connect these results to the curved shapes that these cyanobacteria naturally take while gliding, and quantify the forces generated internally to maintain this shape. The measurements can be used to model interactions between cyanobacteria, or with their environment, and how their collective behaviour emerges from such interactions.
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Affiliation(s)
- Mixon K. Faluweki
- School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, UK
- Malawi Institute of Technology, Malawi University of Science and Technology, Limbe, Malawi
| | - Lucas Goehring
- School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, UK
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4
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Valiei A, Lin N, McKay G, Nguyen D, Moraes C, Hill RJ, Tufenkji N. Surface Wettability Is a Key Feature in the Mechano-Bactericidal Activity of Nanopillars. ACS APPLIED MATERIALS & INTERFACES 2022; 14:27564-27574. [PMID: 35670568 DOI: 10.1021/acsami.2c03258] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Nanopillar-textured surfaces are of growing interest because of their ability to kill bacteria through physical damage without relying on antimicrobial chemicals. Although research on antibacterial nanopillars has progressed significantly in recent years, the effect of nanopillar hydrophobicity on bactericidal activity remains elusive. In this study, we investigated the mechano-bactericidal efficacy of etched silicon nanopillars against Pseudomonas aeruginosa at nanopillar hydrophobicities from superhydrophilic to superhydrophobic. Assessing cell viability and bacterial morphology in immersed wet conditions, we observed negligible bactericidal activity; however, air/liquid interface displacement during water evaporation established a bactericidal effect that strongly depends on substrate hydrophobicity. Specifically, bactericidal activity was highest on superhydrophilic surfaces but abated with increasing hydrophobicity, diminishing at substrate contact angles larger than 90°. Calculation of the surface tension and Laplace pressure forces during water evaporation for each substrate subsequently highlighted that the total capillary force, as an external driving force responsible for bacterial deformation, is significantly weaker on hydrophobic substrates. These findings suggest that superhydrophilic nanopillared surfaces are a superior choice for mechano-bactericidal activity, whereas superhydrophobic surfaces, although not bactericidal, may have antibiofouling properties through their self-cleaning effect. These findings provide new insights into the design and application of nanopillared surfaces as functional antibacterial materials.
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Affiliation(s)
- Amin Valiei
- Department of Chemical Engineering, McGill University, Montreal, Québec H3A 0C5, Canada
| | - Nicholas Lin
- Department of Chemical Engineering, McGill University, Montreal, Québec H3A 0C5, Canada
| | - Geoffrey McKay
- Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre, Montreal, Québec H3A 0G4, Canada
| | - Dao Nguyen
- Meakins-Christie Laboratories, Research Institute of the McGill University Health Centre, Montreal, Québec H3A 0G4, Canada
- Department of Medicine, McGill University, Montreal, Québec H3A 0G4, Canada
| | - Christopher Moraes
- Department of Chemical Engineering, McGill University, Montreal, Québec H3A 0C5, Canada
- Department of Biomedical Engineering, McGill University, Montreal, Québec H3A 2B4, Canada
| | - Reghan J Hill
- Department of Chemical Engineering, McGill University, Montreal, Québec H3A 0C5, Canada
| | - Nathalie Tufenkji
- Department of Chemical Engineering, McGill University, Montreal, Québec H3A 0C5, Canada
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5
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Chen Z, Gu Y, Wang G, Liu Q, Li Y, Weng Y, Lu N, Yang G, Liu Y. Normal Force-Induced Highly Efficient Mechanical Sterilization of GaN Nanopillars. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:856-862. [PMID: 34990133 DOI: 10.1021/acs.langmuir.1c03066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Bacterial residue is one of the main causes of diseases and economic losses. In recent years, microfabrication technology has inspired the introduction of microstructures on the surfaces of relevant materials to provide antibacterial effects. This antibacterial method has become a popular research topic due to its safety, effectiveness, and stability. However, its exact mechanism is still under debate. In this study, normal force was introduced to bacteria on GaN nanopillars to investigate the mechanical sterilization effects and a computer simulation was conducted. The results show that the normal force induces highly efficient mechanical sterilization of the nanopillars, and their surfaces impede the attachment of bacteria. This study provides insights into the antibacterial effect of nanopillars and offers a potential antibacterial tool with high efficiency.
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Affiliation(s)
- Zhe Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China
| | - Yan Gu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China
| | - Gongbo Wang
- College of Mechanical Engineering, Tianjin University, Tianjin 300072, China
| | - Qingrun Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China
| | - Yujie Li
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China
| | - Yuyan Weng
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China
| | - Naiyan Lu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China
- School of Science, Jiangnan University, Wuxi 214122, Jiangsu, China
| | - Guofeng Yang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China
- School of Science, Jiangnan University, Wuxi 214122, Jiangsu, China
| | - Yu Liu
- Microsoft Quantum Materials Lab Copenhagen, 2800 Lyngby, Denmark
- Center for Quantum Devices, Niels Bohr Institute, University of Copenhagen, 2100 Copenhagen, Denmark
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6
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Protasiuk L, Serov NS, Lokteva AV, Kladko D, Koshel EI, Vinogradov VV. Mechano-bactericidal anisotropic particles for oral biofilm treatment. J Mater Chem B 2022; 10:4867-4877. [DOI: 10.1039/d2tb00582d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Bacterial biofilms stand for the main etiological factor of dental diseases worldwide. At present, toothpaste with bactericidal chemicals as well as abrasive materials are used as preventive care. However, chemicals...
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7
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Tardif M, Picard E, Gaude V, Jager JB, Peyrade D, Hadji E, Marcoux PR. On-Chip Optical Nano-Tweezers for Culture-Less Fast Bacterial Viability Assessment. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2103765. [PMID: 34784093 DOI: 10.1002/smll.202103765] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 09/30/2021] [Indexed: 06/13/2023]
Abstract
Because of antibiotics misuse, the dramatic growth of antibioresistance threatens public health. Tests are indeed culture-based, and require therefore one to two days. This long time-to-result implies the use of large-spectrum antibiotherapies as a first step, in absence of pathogen characterization. Here, a breakthrough approach for a culture-less fast assessment of bacterial response to stress is proposed. It is based on non-destructive on-chip optical tweezing. A laser loads an optical nanobeam cavity whose evanescent part of the resonant field acts as a nano-tweezer for bacteria surrounding the cavity. Once optically trapped, the bacterium-nanobeam cavity interaction induces a shift of the resonance driven by the bacterial cell wall optical index. The analysis of the wavelength shift yields an assessment of viability upon stress at the single-cell scale. As a proof of concept, bacteria are stressed by incursion, before optical trapping, at different temperatures (45, 51, and 70 °C). Optical index changes correlate with the degree of thermal stress allowing to sort viable and dead bacteria. With this disruptive diagnosis method, bacterial viability upon stress is probed much faster (typically less than 4 h) than with conventional culture-based enumeration methods (24 h).
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Affiliation(s)
- Manon Tardif
- Univ. Grenoble Alpes, Grenoble INP, CEA, IRIG, Pheliqs, SiNaPS Lab, Grenoble, F-38000, France
- Univ. Grenoble Alpes, CNRS, LTM, Grenoble, F-38000, France
| | - Emmanuel Picard
- Univ. Grenoble Alpes, Grenoble INP, CEA, IRIG, Pheliqs, SiNaPS Lab, Grenoble, F-38000, France
| | - Victor Gaude
- Univ. Grenoble Alpes, CNRS, LTM, Grenoble, F-38000, France
| | - Jean-Baptiste Jager
- Univ. Grenoble Alpes, Grenoble INP, CEA, IRIG, Pheliqs, SiNaPS Lab, Grenoble, F-38000, France
| | - David Peyrade
- Univ. Grenoble Alpes, CNRS, LTM, Grenoble, F-38000, France
| | - Emmanuel Hadji
- Univ. Grenoble Alpes, Grenoble INP, CEA, IRIG, Pheliqs, SiNaPS Lab, Grenoble, F-38000, France
| | - Pierre R Marcoux
- Univ. Grenoble Alpes, CEA, LETI, DTBS, LSIV, Grenoble, F-38000, France
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8
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Eco-friendly bacteria-killing by nanorods through mechano-puncture with top selectivity. Bioact Mater 2021; 15:173-184. [PMID: 35386355 PMCID: PMC8941167 DOI: 10.1016/j.bioactmat.2021.11.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/25/2021] [Accepted: 11/25/2021] [Indexed: 11/20/2022] Open
Abstract
Nanorods can induce mechano-puncture of Staphylococcus aureus (S. aureus) that often impairs osseointegration of orthopedic implants, while the critical nanorod top sharpness able to puncture S. aureus and the predominant contributor between top sharpness and length to mechano-puncture activity remains elusive. Herein, we fabricated three kinds of Al2O3-wrapped nanorods patterned arrays with different lengths and top sharpness. The top-sharp nanorods have lengths of 469 and 884 nm and the shorter show a length identical to the top-flat nanorods. Driven by the equivalent adhesive force of S. aureus, the top-flat nanorods deform cell envelops, showing a bacteriostatic rate of 29% owing to proliferation-inhibited manner. The top-sharp nanorods puncture S. aureus, showing a bactericidal rate of 96% for the longer, and 98% for the shorter that simultaneously exhibits fair osseointegration in bacteria-infected rat tibias, identifying top sharpness as a predominate contributor to mechano-puncture activity. Based on finite-element simulation, such top-flat nanorod derives the maximum stress (Smax) of 5.65 MPa on cell wall, lower than its ultimate-tensile-strength (13 MPa); while such top-sharp and shorter nanorod derives Smax of 20.15 MPa to puncture cell envelop. Moreover, a critical top conical angle of 138° is identified for nanorods able to puncture S. aureus. Top sharpness depended mechano-puncture of nanorods against S. aureus is clarified. Top-flat nanorods deform bacterial cell envelop to inhibit their proliferation. Top-sharp nanorods (conical angle of 50°) puncture bacteria to intensely kill them. 138° is confirmed as critical top conical angle for nanorods to puncture S. aureus.
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9
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Surface architecture of Neisseria meningitidis capsule and outer membrane as revealed by Atomic Force Microscopy. Res Microbiol 2021; 172:103865. [PMID: 34284091 DOI: 10.1016/j.resmic.2021.103865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 07/03/2021] [Accepted: 07/06/2021] [Indexed: 11/21/2022]
Abstract
An extensive morphological analysis of the Neisseria meningitidis cell envelope, including serogroup B capsule and outer membrane, based on atomic force microscopy (AFM) together with mechanical characterization by force spectroscopic measurements, has been carried out. Three meningococcal strains were used: the encapsulated serogroup B strain B1940, and the isogenic mutants B1940 siaD(+C) (lacking capsule), and B1940 cps (lacking both capsule and lipooligosaccharide outer core). regularly structured AFM experiments with the encapsulated strain B1940 provided unprecedented images of the meningococcal capsule, which seems to be characterized by protrusions ("bumps") with the lateral dimensions of about 30 nm. Measurement of the Young's modulus provided quantitative assessment of the property of the capsule to confer resistance to mechanical stress. Moreover, Raman spectroscopy gave a fingerprint by which it was possible to identify the specific molecular species of the three strains analyzed, and to highlight major differences between them.
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10
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Cui Q, Liu T, Li X, Zhao L, Wu Q, Wang X, Song K, Ge D. Validation of the mechano-bactericidal mechanism of nanostructured surfaces with finite element simulation. Colloids Surf B Biointerfaces 2021; 206:111929. [PMID: 34147928 DOI: 10.1016/j.colsurfb.2021.111929] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 06/02/2021] [Accepted: 06/14/2021] [Indexed: 10/21/2022]
Abstract
The mechano-bactericidal property of nanostructured surfaces has become the focus of intensive research toward the development of a new generation of antibacterial surfaces, especially in the current era of spreading antibiotic resistance. However, the mechanisms underlying nanostructured surfaces mechanically damaging bacteria remain unclear, which ultimately limits translational potential toward real-world applications. Using finite element simulation technique, we developed the three-dimensional thin wall with turgor pressure finite element model (3D-TWTP-FEM) of bacterial cell and verified the reliability of this model by the AFM indentation experiment simulation of the cell, and the cell model is able to simulate suspended bacterial cell and the process of cell adhering to the flat and nanopillar surfaces. Since bacterial cells suffer greater stress and deformation on the nanopillar surfaces, a two-stage model of the elastic and creep deformation stage of the cells on the nanostructured surfaces was developed. The calculations show that the location of the maximum stress/strain on the cells adhered to the nanopillar surfaces is at the liquid-cell-nanopillar three phase contact line. The computational results confirmed the ability of nanostructured surfaces to mechanically lyse bacteria and gave the effect of nanopillar geometry on the efficiency and speed of bacterial cell rupture. This study provides fundamental physical insights into how nanopillar surfaces can serve as effective and fast mechanical antimicrobial materials.
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Affiliation(s)
- Qianqian Cui
- School of Chemical Engineering, Dalian University of Technology, Dalian, 116024, Liaoning Province, PR China
| | - Tianqing Liu
- School of Chemical Engineering, Dalian University of Technology, Dalian, 116024, Liaoning Province, PR China.
| | - Xiangqin Li
- School of Chemical Engineering, Dalian University of Technology, Dalian, 116024, Liaoning Province, PR China
| | - Lidan Zhao
- School of Chemical Engineering, Dalian University of Technology, Dalian, 116024, Liaoning Province, PR China
| | - Qiqi Wu
- School of Chemical Engineering, Dalian University of Technology, Dalian, 116024, Liaoning Province, PR China
| | - Xin Wang
- School of Chemical Engineering, Dalian University of Technology, Dalian, 116024, Liaoning Province, PR China
| | - Kedong Song
- School of Chemical Engineering, Dalian University of Technology, Dalian, 116024, Liaoning Province, PR China
| | - Dan Ge
- School of Chemical Engineering, Dalian University of Technology, Dalian, 116024, Liaoning Province, PR China
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11
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de Jonge PA, Smit Sibinga DJC, Boright OA, Costa AR, Nobrega FL, Brouns SJJ, Dutilh BE. Development of Styrene Maleic Acid Lipid Particles as a Tool for Studies of Phage-Host Interactions. J Virol 2020; 94:e01559-20. [PMID: 32938760 PMCID: PMC7654272 DOI: 10.1128/jvi.01559-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 09/08/2020] [Indexed: 01/08/2023] Open
Abstract
The infection of a bacterium by a phage starts with attachment to a receptor molecule on the host cell surface by the phage. Since receptor-phage interactions are crucial to successful infections, they are major determinants of phage host range and, by extension, of the broader effects that phages have on bacterial communities. Many receptor molecules, particularly membrane proteins, are difficult to isolate because their stability is supported by their native membrane environments. Styrene maleic acid lipid particles (SMALPs), a recent advance in membrane protein studies, are the result of membrane solubilizations by styrene maleic acid (SMA) copolymer chains. SMALPs thereby allow for isolation of membrane proteins while maintaining their native environment. Here, we explore SMALPs as a tool to isolate and study phage-receptor interactions. We show that SMALPs produced from taxonomically distant bacterial membranes allow for receptor-specific decrease of viable phage counts of several model phages that span the three largest phage families. After characterizing the effects of incubation time and SMALP concentration on the activity of three distinct phages, we present evidence that the interaction between two model phages and SMALPs is specific to bacterial species and the phage receptor molecule. These interactions additionally lead to DNA ejection by nearly all particles at high phage titers. We conclude that SMALPs are a potentially highly useful tool for phage-host interaction studies.IMPORTANCE Bacteriophages (viruses that infect bacteria or phages) impact every microbial community. All phage infections start with the binding of the viral particle to a specific receptor molecule on the host cell surface. Due to its importance in phage infections, this first step is of interest to many phage-related research and applications. However, many phage receptors are difficult to isolate. Styrene maleic acid lipid particles (SMALPs) are a recently developed approach to isolate membrane proteins in their native environment. In this study, we explore SMALPs as a tool to study phage-receptor interactions. We find that different phage species bind to SMALPs, while maintaining specificity to their receptor. We then characterize the time and concentration dependence of phage-SMALP interactions and furthermore show that they lead to genome ejection by the phage. The results presented here show that SMALPs are a useful tool for future studies of phage-receptor interactions.
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Affiliation(s)
- Patrick A de Jonge
- Theoretical Biology and Bioinformatics, Science4Life, Utrecht University, Utrecht, The Netherlands
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Dieuwke J C Smit Sibinga
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Oliver A Boright
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Ana Rita Costa
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Franklin L Nobrega
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Stan J J Brouns
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Bas E Dutilh
- Theoretical Biology and Bioinformatics, Science4Life, Utrecht University, Utrecht, The Netherlands
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12
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Gil-Santos E, Ruz JJ, Malvar O, Favero I, Lemaître A, Kosaka PM, García-López S, Calleja M, Tamayo J. Optomechanical detection of vibration modes of a single bacterium. NATURE NANOTECHNOLOGY 2020; 15:469-474. [PMID: 32284570 DOI: 10.1038/s41565-020-0672-y] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Accepted: 03/09/2020] [Indexed: 05/10/2023]
Abstract
Low-frequency vibration modes of biological particles, such as proteins, viruses and bacteria, involve coherent collective vibrations at frequencies in the terahertz and gigahertz domains. These vibration modes carry information on their structure and mechanical properties, which are good indicators of their biological state. In this work, we harnessed a particular regime in the physics of coupled mechanical resonators to directly measure these low-frequency mechanical resonances of a single bacterium. We deposit the bacterium on the surface of an ultrahigh frequency optomechanical disk resonator in ambient conditions. The vibration modes of the disk and bacterium hybridize when their associated frequencies are similar. We developed a general theoretical framework to describe this coupling, which allows us to retrieve the eigenfrequencies and mechanical loss of the bacterium low-frequency vibration modes (quality factor). Additionally, we analysed the effect of hydration on these vibrational modes. This work demonstrates that ultrahigh frequency optomechanical resonators can be used for vibrational spectrometry with the unique capability to obtain information on single biological entities.
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Affiliation(s)
- Eduardo Gil-Santos
- Bionanomechanics Lab, Instituto de Micro y Nanotecnología, IMN-CNM (CSIC), Madrid, Spain.
| | - Jose J Ruz
- Bionanomechanics Lab, Instituto de Micro y Nanotecnología, IMN-CNM (CSIC), Madrid, Spain
| | - Oscar Malvar
- Bionanomechanics Lab, Instituto de Micro y Nanotecnología, IMN-CNM (CSIC), Madrid, Spain
| | - Ivan Favero
- Matériaux et Phénomènes Quantiques, Université de Paris, CNRS, Paris, France
| | - Aristide Lemaître
- Centre de Nanosciences et Nanotechnologies, CNRS, Université Paris-Saclay, Palaiseau, France
| | - Priscila M Kosaka
- Bionanomechanics Lab, Instituto de Micro y Nanotecnología, IMN-CNM (CSIC), Madrid, Spain
| | - Sergio García-López
- Bionanomechanics Lab, Instituto de Micro y Nanotecnología, IMN-CNM (CSIC), Madrid, Spain
| | - Montserrat Calleja
- Bionanomechanics Lab, Instituto de Micro y Nanotecnología, IMN-CNM (CSIC), Madrid, Spain
| | - Javier Tamayo
- Bionanomechanics Lab, Instituto de Micro y Nanotecnología, IMN-CNM (CSIC), Madrid, Spain.
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Kosel J, Šuštaršič M, Petkovšek M, Zupanc M, Sežun M, Dular M. Application of (super)cavitation for the recycling of process waters in paper producing industry. ULTRASONICS SONOCHEMISTRY 2020; 64:105002. [PMID: 32045832 DOI: 10.1016/j.ultsonch.2020.105002] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 02/03/2020] [Accepted: 02/03/2020] [Indexed: 05/07/2023]
Abstract
In paper production industry, microbial contaminations of process waters are common and can cause damage to paper products and equipment as well as the occurrence of pathogens in the end products. Chlorine omission has led to the usage of costly reagents and products of lower mechanical quality. In this study, we have tested a rotation generator equipped with two sets of rotor and stator assemblies to generate developed cavitation (unsteady cloud shedding with pressure pulsations) or supercavitation (a steady cavity in chocked cavitation conditions) for the destruction of a persistent bacteria Bacillus subtilis. Our results showed that only supercavitation was effective and was further employed for the treatment of waters isolated from an enclosed water recycle system in a paper producing plant. The water quality was monitored and assessed according to the chemical (COD, redox potential and dissolved oxygen), physical (settleable solids, insolubles and colour intensity) and biological methods (yeasts, aerobic and anaerobic bacteria, bacterial spores and moulds). After one hour of treatment, a strong 4 logs reduction was achieved for the anaerobic sulphate reducing bacteria and for the yeasts; a 3 logs reduction for the aerobic bacteria; and a 1.3 logs reduction for the heat resistant bacterial spores. A 22% reduction in COD and an increase in the redox potential (37%) were observed. Sediments were reduced by 50% and the insoluble particles by 67%. For bacterial destruction in real industrial process waters, the rotation generator of supercavitation spent 4 times less electrical energy in comparison to the previously published cavitation treatments inside the Venturi constriction design.
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Affiliation(s)
- Janez Kosel
- Institute for the Protection of Cultural Heritage of Slovenia, Slovenia.
| | | | - Martin Petkovšek
- Faculty of Mechanical Engineering, University of Ljubljana, Slovenia
| | - Mojca Zupanc
- Faculty of Mechanical Engineering, University of Ljubljana, Slovenia
| | - Mija Sežun
- Pulp and Paper Institute of Ljubljana, Slovenia
| | - Matevž Dular
- Faculty of Mechanical Engineering, University of Ljubljana, Slovenia
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14
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Collett S, Torresi J, Earnest-Silveira L, Christiansen D, Elbourne A, Ramsland PA. Probing and pressing surfaces of hepatitis C virus-like particles. J Colloid Interface Sci 2019; 545:259-268. [DOI: 10.1016/j.jcis.2019.03.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 03/07/2019] [Accepted: 03/09/2019] [Indexed: 02/09/2023]
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15
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Velic A, Tesfamichael T, Li Z, Yarlagadda PK. Parametric Study on Nanopattern Bactericidal Activity. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.promfg.2019.02.072] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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16
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Study of the tensile properties of individual multicellular fibres generated by Bacillus subtilis. Sci Rep 2017; 7:46052. [PMID: 28378797 PMCID: PMC5380956 DOI: 10.1038/srep46052] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 03/07/2017] [Indexed: 11/09/2022] Open
Abstract
Multicellular fibres formed by Bacillus subtilis (B. subtilis) are attracting interest because of their potential application as degradable biomaterials. However, mechanical properties of individual fibres remain unknown because of their small dimensions. Herein, a new approach is developed to investigate the tensile properties of individual fibres with an average diameter of 0.7 μm and a length range of 25.7–254.3 μm. Variations in the tensile strengths of fibres are found to be the result of variable interactions among pairs of microbial cells known as septa. Using Weibull weakest-link model to study this mechanical variability, we predict the length effect of the sample. Moreover, the mechanical properties of fibres are found to depend highly on relative humidity (RH), with a brittle–ductile transition occurring around RH = 45%. The elastic modulus is 5.8 GPa in the brittle state, while decreases to 62.2 MPa in the ductile state. The properties of fibres are investigated by using a spring model (RH < 45%) for its elastic behaviour, and the Kelvin–Voigt model (RH > 45%) for the time-dependent response. Loading-unloading experiments and numerical calculations demonstrate that necking instability comes from structural changes (septa) and viscoelasticity dominates the deformation of fibres at high RH.
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17
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Atomic force microscopy for the investigation of molecular and cellular behavior. Micron 2016; 89:60-76. [DOI: 10.1016/j.micron.2016.07.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 07/27/2016] [Indexed: 12/19/2022]
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18
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Noue ACDL, Peters J, Gervais P, Martinez N, Perrier-Cornet JM, Natali F. Proton dynamics in bacterial spores, a neutron scattering investigation. EPJ WEB OF CONFERENCES 2015. [DOI: 10.1051/epjconf/20158302003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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19
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Gao S, Lewis GD, Ashokkumar M, Hemar Y. Inactivation of microorganisms by low-frequency high-power ultrasound: 1. Effect of growth phase and capsule properties of the bacteria. ULTRASONICS SONOCHEMISTRY 2014; 21:446-53. [PMID: 23835398 DOI: 10.1016/j.ultsonch.2013.06.006] [Citation(s) in RCA: 130] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 05/28/2013] [Accepted: 06/04/2013] [Indexed: 05/13/2023]
Abstract
The aim of this study was to determine the effects of high-intensity low-frequency (20 kHz) ultrasound treatment on the viability of bacteria suspension. More specifically, we have investigated the relationship between the deactivation efficiency and the physical (size, hydrophobicity) and biological (gram-status, growth phase) properties of the microbes. Enterobacter aerogenes, Bacillus subtilis, Staphylococcus epidermidis, S. epidermidis SK and Staphylococcus pseudintermedius were chosen for this study owing to their varying physical and biological properties. The survival ratio of the bacteria suspension was measured as a function of the ultrasound power (up to 13 W) for a constant sonication time of 20 min. Transmission electron microscopy was used to evaluate the ultrasound-induced damages to the microbes. Ultrasound treatment resulted in lethal damage to E. aerogenes and B. subtilis (up to 4.5-log reduction), whereas Staphylococcus spp. were not affected noticeably. Further, E. aerogenes suspensions were more sensitive to ultrasonication in exponential growth phase than when they were in stationary phase. The results of this study demonstrate that the main reason for bacterial resistance to ultrasonic deactivation is due to the properties of the bacterial capsule. Microbes with a thicker and "soft" capsule are highly resistant to ultrasonic deactivation process.
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Affiliation(s)
- Shengpu Gao
- School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand; School of Biological Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand; Institute of Food and Agricultural Standardization, China National Institute of Standardization, Beijing 10088, China
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20
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Dhahri S, Ramonda M, Marlière C. In-situ determination of the mechanical properties of gliding or non-motile bacteria by atomic force microscopy under physiological conditions without immobilization. PLoS One 2013; 8:e61663. [PMID: 23593493 PMCID: PMC3625152 DOI: 10.1371/journal.pone.0061663] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Accepted: 03/12/2013] [Indexed: 11/19/2022] Open
Abstract
We present a study about AFM imaging of living, moving or self-immobilized bacteria in their genuine physiological liquid medium. No external immobilization protocol, neither chemical nor mechanical, was needed. For the first time, the native gliding movements of Gram-negative Nostoc cyanobacteria upon the surface, at speeds up to 900 µm/h, were studied by AFM. This was possible thanks to an improved combination of a gentle sample preparation process and an AFM procedure based on fast and complete force-distance curves made at every pixel, drastically reducing lateral forces. No limitation in spatial resolution or imaging rate was detected. Gram-positive and non-motile Rhodococcus wratislaviensis bacteria were studied as well. From the approach curves, Young modulus and turgor pressure were measured for both strains at different gliding speeds and are ranging from 20±3 to 105±5 MPa and 40±5 to 310±30 kPa depending on the bacterium and the gliding speed. For Nostoc, spatially limited zones with higher values of stiffness were observed. The related spatial period is much higher than the mean length of Nostoc nodules. This was explained by an inhomogeneous mechanical activation of nodules in the cyanobacterium. We also observed the presence of a soft extra cellular matrix (ECM) around the Nostoc bacterium. Both strains left a track of polymeric slime with variable thicknesses. For Rhodococcus, it is equal to few hundreds of nanometers, likely to promote its adhesion to the sample. While gliding, the Nostoc secretes a slime layer the thickness of which is in the nanometer range and increases with the gliding speed. This result reinforces the hypothesis of a propulsion mechanism based, for Nostoc cyanobacteria, on ejection of slime. These results open a large window on new studies of both dynamical phenomena of practical and fundamental interests such as the formation of biofilms and dynamic properties of bacteria in real physiological conditions.
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Affiliation(s)
- Samia Dhahri
- Géosciences Montpellier, University Montpellier 2, CNRS, Montpellier, France
| | - Michel Ramonda
- Centrale de Technologie en Micro et nanoélectronique, Laboratoire de Microscopie en Champ Proche, University Montpellier 2, Montpellier, France
| | - Christian Marlière
- Géosciences Montpellier, University Montpellier 2, CNRS, Montpellier, France
- Institut des Sciences Moléculaires d'Orsay, University Paris-Sud, CNRS, Orsay, France
- * E-mail:
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21
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Tuson HH, Auer GK, Renner LD, Hasebe M, Tropini C, Salick M, Crone WC, Gopinathan A, Huang KC, Weibel DB. Measuring the stiffness of bacterial cells from growth rates in hydrogels of tunable elasticity. Mol Microbiol 2012; 84:874-91. [PMID: 22548341 DOI: 10.1111/j.1365-2958.2012.08063.x] [Citation(s) in RCA: 163] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Although bacterial cells are known to experience large forces from osmotic pressure differences and their local microenvironment, quantitative measurements of the mechanical properties of growing bacterial cells have been limited. We provide an experimental approach and theoretical framework for measuring the mechanical properties of live bacteria. We encapsulated bacteria in agarose with a user-defined stiffness, measured the growth rate of individual cells and fit data to a thin-shell mechanical model to extract the effective longitudinal Young's modulus of the cell envelope of Escherichia coli (50-150 MPa), Bacillus subtilis (100-200 MPa) and Pseudomonas aeruginosa (100-200 MPa). Our data provide estimates of cell wall stiffness similar to values obtained via the more labour-intensive technique of atomic force microscopy. To address physiological perturbations that produce changes in cellular mechanical properties, we tested the effect of A22-induced MreB depolymerization on the stiffness of E. coli. The effective longitudinal Young's modulus was not significantly affected by A22 treatment at short time scales, supporting a model in which the interactions between MreB and the cell wall persist on the same time scale as growth. Our technique therefore enables the rapid determination of how changes in genotype and biochemistry affect the mechanical properties of the bacterial envelope.
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Affiliation(s)
- Hannah H Tuson
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
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22
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Furchtgott L, Wingreen NS, Huang KC. Mechanisms for maintaining cell shape in rod-shaped Gram-negative bacteria. Mol Microbiol 2011; 81:340-53. [PMID: 21501250 DOI: 10.1111/j.1365-2958.2011.07616.x] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
For the rod-shaped Gram-negative bacterium Escherichia coli, changes in cell shape have critical consequences for motility, immune system evasion, proliferation and adhesion. For most bacteria, the peptidoglycan cell wall is both necessary and sufficient to determine cell shape. However, how the synthesis machinery assembles a peptidoglycan network with a robustly maintained micron-scale shape has remained elusive. To explore shape maintenance, we have quantified the robustness of cell shape in three Gram-negative bacteria in different genetic backgrounds and in the presence of an antibiotic that inhibits division. Building on previous modelling suggesting a prominent role for mechanical forces in shape regulation, we introduce a biophysical model for the growth dynamics of rod-shaped cells to investigate the roles of spatial regulation of peptidoglycan synthesis, glycan-strand biochemistry and mechanical stretching during insertion. Our studies reveal that rod-shape maintenance requires insertion to be insensitive to fluctuations in cell-wall density and stress, and even a simple helical pattern of insertion is sufficient for over sixfold elongation without significant loss in shape. In addition, we demonstrate that both the length and pre-stretching of newly inserted strands regulate cell width. In sum, we show that simple physical rules can allow bacteria to achieve robust, shape-preserving cell-wall growth.
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Affiliation(s)
- Leon Furchtgott
- Department of Bioengineering, 318 Campus Drive West, Stanford University, Stanford, CA 94305, USA
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23
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Nackos AN, Truong TV, Pulsipher TC, Kimball JA, Tolley HD, Robison RA, Bartholomew CH, Lee ML. One-step conversion of to its using salts for GC-MSdetection of bacterial endospores. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2011; 3:245-258. [PMID: 32938021 DOI: 10.1039/c0ay00270d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Methyl sulfate (MeSO4-) salts were explored as thermochemolysis-methylation (TCM) reagents for gas chromatographic (GC) analysis of dipicolinic acid (DPA) as its dimethyl ester (Me2DPA) from bacterial endospores. The reaction was carried out under non-pyrolytic conditions by inserting a small coiled wire filament coated with the sample and reagents directly inside a GC injection port at 290 °C. Above 10 : 1 methyl donor/DPA ratios, alkali metal salts of MeSO4- effected 80-90% conversion of DPA to Me2DPA, which was 10-20 times more active than the same amount of tetramethylammonium hydroxide (TMA-OH) at this temperature. A quaternary salt mixture consisting of 1 : 3 : 1 : 3 TMA+/Na+/OH-/MeSO4- methylated spore DPA with an average conversion of 86% (mean conversion by TMA-OH under the same conditions was 4%). Therefore, the sensitivity for detection of bacterial endospores was increased over 20-fold compared to that observed with the more commonly employed TMA-OH methylating reagent. The limit of detection by this method was 9 × 104 total spores. Mechanisms describing the observed behavior are proposed and discussed. This is the first use of MeSO4- as a TCM reagent for GC.
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Affiliation(s)
- Aaron N Nackos
- Department of Chemical Engineering, Brigham Young University, Provo, UT 84602, USA.
| | - Tai V Truong
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602, USA.
| | | | - Jon A Kimball
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602, USA.
| | - H Dennis Tolley
- Department of Statistics, Brigham Young University, Provo, UT 84602, USA
| | - Richard A Robison
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT 84602, USA
| | - Calvin H Bartholomew
- Department of Chemical Engineering, Brigham Young University, Provo, UT 84602, USA.
| | - Milton L Lee
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602, USA.
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24
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Liu S, Ng AK, Xu R, Wei J, Tan CM, Yang Y, Chen Y. Antibacterial action of dispersed single-walled carbon nanotubes on Escherichia coli and Bacillus subtilis investigated by atomic force microscopy. NANOSCALE 2010; 2:2744-2750. [PMID: 20877897 DOI: 10.1039/c0nr00441c] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Single-walled carbon nanotubes (SWCNTs) exhibit strong antibacterial activities. Direct contact between bacterial cells and SWCNTs may likely induce cell damages. Therefore, the understanding of SWCNT-bacteria interactions is essential in order to develop novel SWCNT-based materials for their potential environmental, imaging, therapeutic, and military applications. In this preliminary study, we utilized atomic force microscopy (AFM) to monitor dynamic changes in cell morphology and mechanical properties of two typical bacterial models (gram-negative Escherichia coli and gram-positive Bacillus subtilis) upon incubation with SWCNTs. The results demonstrated that individually dispersed SWCNTs in solution develop nanotube networks on the cell surface, and then destroy the bacterial envelopes with leakage of the intracellular contents. The cell morphology changes observed on air dried samples are accompanied by an increase in cell surface roughness and a decrease in surface spring constant. To mimic the collision between SWCNTs and cells, a sharp AFM tip of 2 nm was chosen to introduce piercings on the cell surface. No clear physical damages were observed if the applied force was below 10 nN. Further analysis also indicates that a single collision between one nanotube and a bacterial cell is unlikely to introduce direct physical damage. Hence, the antibacterial activity of SWCNTs is the accumulation effect of large amount of nanotubes through interactions between SWCNT networks and bacterial cells.
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Affiliation(s)
- Shaobin Liu
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore 637459
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25
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New Insight into the Thermal Properties and the Biological Behaviour of the Bacterial Spores. FOOD BIOPHYS 2010. [DOI: 10.1007/s11483-010-9165-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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26
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Park BJ, Abu-Lail NI. Variations in the Nanomechanical Properties of Virulent and Avirulent Listeria monocytogenes. SOFT MATTER 2010; 6:3898-3909. [PMID: 20871743 PMCID: PMC2944262 DOI: 10.1039/b927260g] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Atomic force microscopy (AFM) was used to quantify both the nanomechanical properties of pathogenic (ATCC 51776 & EGDe) and non-pathogenic (ATCC 15313 & HCC25) Listeria monocytogenes strains and the conformational properties of their surface biopolymers. The nanomechanical properties of the various L. monocytogenes strains were quantified in terms of Young's moduli of cells. To estimate Young's moduli, the classic Hertz model of contact mechanics and a modified version of it that takes into account substrate effects were used to fit the AFM nanoindentation-force measurements collected while pushing onto the bacterial surface biopolymer brush. When compared, the classic Hertz model always predicted higher Young's moduli values of bacterial cell elasticity compared to the modified Hertz model. On average, the modified Hertz model showed that virulent strains are approximately twice as rigid (88.1 ± 14.5 KPa) as the avirulent strains (47.3 ± 7.6 kPa). To quantify the conformational properties of L. monocytogenes' strains surface biopolymers, two models were used. First, the entropic-based, statistical mechanical, random walk formulation, the wormlike chain (WLC) model was used to estimate the elastic properties of the bacterial surface molecules. The WLC model results indicated that the virulent strains are characterized by a more flexible surface biopolymers as indicated by shorter persistence lengths (L(p) = 0.21 ± 0.08 nm) compared to the avirulent strains (L(p) = 0.24 ± 0.14 nm). Second, a steric model developed to describe the repulsive forces measured between the AFM tip and bacterial surface biopolymers indicated that the virulent strains are characterized by crowded and longer biopolymer brushes compared to those of the avirulent strains. Finally, scaling relationships developed for grafted polyelectrolyte brushes indicated L. monocytogenes strains' biopolymer brushes are charged. Collectively, our data indicate that the conformational properties of the bacterial surface biopolymers and their surface densities play an important role in controlling the overall bacterial cell elasticity.
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Affiliation(s)
| | - Nehal I. Abu-Lail
- Corresponding Author: Nehal I. Abu-Lail, Ph.D., Gene and Linda Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA 99164-2710, United States, , 509-335-4961
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27
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Liu S, Wei L, Hao L, Fang N, Chang MW, Xu R, Yang Y, Chen Y. Sharper and faster "nano darts" kill more bacteria: a study of antibacterial activity of individually dispersed pristine single-walled carbon nanotube. ACS NANO 2009; 3:3891-902. [PMID: 19894705 DOI: 10.1021/nn901252r] [Citation(s) in RCA: 305] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
To further our understanding on the antibacterial activity of single-walled carbon nanotubes (SWCNTs), high purity SWCNTs with average diameter of 0.83 nm and (7,5) chirality as dominate (n,m) structure were dispersed in a biocompatible surfactant solution. Ultraviolet-visible-near-infrared radiation absorption spectroscopy was employed to monitor the aggregation of SWCNTs. The results demonstrated that individually dispersed SWCNTs were more toxic than SWCNT aggregates toward bacteria (gram-negative Escherichia coli, Pseudomonas aeruginosa, and gram-positive Staphylococcus aureus, Bacillus subtilis). Individually dispersed SWCNTs can be visualized as numerous moving "nano darts" in the solution, constantly attacking the bacteria; thereby, degrading the bacterial cell integrity and causing the cell death. Controlled experimental results suggested that inhibiting cell growth and oxidative stress were not the major causes responsible for the death of cells. Furthermore, the detrimental effects of Co metal residues (up to 1 mug/mL) on SWCNT samples can be ruled out. Atomic force microscope study conducted in suspension proved that the death rates of bacteria were strongly correlated with their mechanical properties; soft cells were more vulnerable to SWCNT piercing. The antibacterial activity of SWCNTs can be remarkably improved by enhancing the SWCNT physical puncture on bacteria in the following ways: (1) dispersing SWCNTs individually to sharpen the nano darts; (2) increasing SWCNT concentration to raise the population density of nano darts; and (3) elevating the shaking speed of incubation to speed up the nano darts. This study elucidated several factors controlling the antibacterial activity of pristine SWCNTs and it provided an insight in developing strategies that can maximize the SWCNT application potentials while minimizing the health and environment risks.
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Affiliation(s)
- Shaobin Liu
- School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore
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28
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Mahalanabis M, Al-Muayad H, Kulinski MD, Altman D, Klapperich CM. Cell lysis and DNA extraction of gram-positive and gram-negative bacteria from whole blood in a disposable microfluidic chip. LAB ON A CHIP 2009; 9:2811-7. [PMID: 19967118 DOI: 10.1039/b905065p] [Citation(s) in RCA: 127] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Sepsis caused by gram positive and gram negative bacteria is the leading cause of death in noncoronary ICUs and the tenth leading cause of death in the United States. We have developed a microfluidic sample preparation platform for rapid on-chip detection of infectious organisms for point-of-care diagnostics. The microfluidic chips are made of a robust thermoplastic and can be easily multiplexed for high throughput applications. Bacteria are lysed on-chip via hybrid chemical/mechanical method. Once lysed, the bacterial DNA is isolated using a microscale silica bead/polymer composite solid-phase-extraction (SPE) column. Lysis was confirmed using off-chip real time PCR. We isolated and detected both gram-negative (Escherichia coli) and gram-positive (Bacillussubtilis and Enterococcus faecalis) bacterial genomic DNA from microliter scale spiked whole human blood samples. The system performs better for gram-negative bacteria than it does for gram-positive bacteria, with limits of detection at 10(2) CFU/ml and 10(3)-10(4) CFU/ml, respectively. Total extraction times are less than one hour and can be further decreased by altering the channel geometry and pumping configuration.
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29
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Ye X, Xu L, Li X, Chen Z, Zhang B, Yuan L, Chen X, Zhang H, Chang W, Sun S. Antibacterial mechanism of houttuyfonate homologues against Bacillus subtilis. Colloids Surf A Physicochem Eng Asp 2009. [DOI: 10.1016/j.colsurfa.2009.09.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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30
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Zhao L, Schaefer D, Xu H, Modi SJ, LaCourse WR, Marten MR. Elastic Properties of the Cell Wall of Aspergillus nidulans Studied with Atomic Force Microscopy. Biotechnol Prog 2008; 21:292-9. [PMID: 15903268 DOI: 10.1021/bp0497233] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Currently, little is known about the mechanical properties of filamentous fungal hyphae. To study this topic, atomic force microscopy (AFM) was used to measure cell wall mechanical properties of the model fungus Aspergillus nidulans. Wild type and a mutant strain (deltacsmA), lacking one of the chitin synthase genes, were grown in shake flasks. Hyphae were immobilized on polylysine-coated coverslips and AFM force--displacement curves were collected. When grown in complete medium, wild-type hyphae had a cell wall spring constant of 0.29 +/- 0.02 N/m. When wild-type and mutant hyphae were grown in the same medium with added KCl (0.6 M), hyphae were significantly less rigid with spring constants of 0.17 +/- 0.01 and 0.18 +/- 0.02 N/m, respectively. Electron microscopy was used to measure the cell wall thickness and hyphal radius. By use of finite element analysis (FEMLAB v 3.0, Burlington, MA) to simulate AFM indentation, the elastic modulus of wild-type hyphae grown in complete medium was determined to be 110 +/- 10 MPa. This decreased to 64 +/- 4 MPa for hyphae grown in 0.6 M KCl, implying growth medium osmotic conditions have significant effects on cell wall elasticity. Mutant hyphae grown in KCl-supplemented medium were found to have an elastic modulus of 67 +/- 6 MPa. These values are comparable with other microbial systems (e.g., yeast and bacteria). It was also found that under these growth conditions axial variation in elastic modulus along fungal hyphae was small. To determine the relationship between composition and mechanical properties, cell wall composition was measured by anion-exchange liquid chromatography and pulsed electrochemical detection. Results show similar composition between wild-type and mutant strains. Together, these data imply differences in mechanical properties may be dependent on varying molecular structure of hyphal cell walls as opposed to wall composition.
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Affiliation(s)
- Liming Zhao
- Department of Chemical and Biochemical Engineering, University of Maryland-Baltimore County, Baltimore, Maryland 21250, USA
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31
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Rossetto G, Bergese P, Colombi P, Depero LE, Giuliani A, Nicoletto SF, Pirri G. Atomic force microscopy evaluation of the effects of a novel antimicrobial multimeric peptide on Pseudomonas aeruginosa. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2007; 3:198-207. [PMID: 17702663 DOI: 10.1016/j.nano.2007.06.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2007] [Revised: 05/23/2007] [Accepted: 06/22/2007] [Indexed: 01/01/2023]
Abstract
In this article we evaluated by atomic force microscopy (AFM) the effects of the (novel) tetrabranched antimicrobial peptide SB006 on morphology and mechanical properties of the gram-negative bacterium Pseudomonas aeruginosa. AFM imaging showed that SB006 causes the appearance of significant fragmentariness in the bacterial membrane and a severe volume decrease. Quantitative evaluation of the degree of fragmentariness was allowed by a new ad hoc image analysis procedure. The rigidity of the treated and untreated bacteria was measured through AFM tip nanoindentation measurements, and no differences registered. These results support the membrane interaction hypothesis, according to which SB006 targets the bacterial membranes and disrupts their permeability (allowing the leakage of cytoplasmic material and the subsequent shrinkage), but it does not affect the bacterium wall, which determines its rigidity.
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Affiliation(s)
- Greta Rossetto
- INSTM and Laboratorio di Chimica per le Tecnologie, Università di Brescia, Brescia, Italy
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Stecchini ML, Del Torre M, Venir E, Morettin A, Furlan P, Maltini E. Glassy state in Bacillus subtilis spores analyzed by differential scanning calorimetry. Int J Food Microbiol 2006; 106:286-90. [PMID: 16257078 DOI: 10.1016/j.ijfoodmicro.2005.06.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2004] [Revised: 04/01/2005] [Accepted: 06/30/2005] [Indexed: 10/25/2022]
Abstract
Thermal properties of dried spores of Bacillus subtilis, investigated by differential scanning calorimetry (DSC), were studied. A reversible heat capacity shift ascribable to glass-rubber transition was observed at 90-115 degrees C. The transition was found to be a pressure-inhibited volume-activated event. The decoated spores and the extracted peptidoglycan material exhibited glass transition, suggesting that the cortex could be involved in the event. Furthermore, the glass transition was evident when spores were treated with strong acid, and when the isogenic strain PS578 was scanned, indicating that core integrity and core components are not involved in the occurrence of the event. These results suggest that in the dried B. subtilis spores an amorphous biomaterial, possibly the cortex peptidoglycan, is present as a glass.
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Affiliation(s)
- Mara Lucia Stecchini
- Department of Food Science, University of Udine, Via Marangoni n. 97, 33100 Udine, Italy.
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A Comparison of the Mechanical Properties of Different Bacterial Species. Appl Microbiol 2005. [DOI: 10.1007/0-306-46888-3_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Pelling AE, Li Y, Shi W, Gimzewski JK. Nanoscale visualization and characterization of Myxococcus xanthus cells with atomic force microscopy. Proc Natl Acad Sci U S A 2005; 102:6484-9. [PMID: 15840722 PMCID: PMC1088375 DOI: 10.1073/pnas.0501207102] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Multicellular microbial communities are the predominant form of existence for microorganisms in nature. As one of the most primitive social organisms, Myxococcus xanthus has been an ideal model bacterium for studying intercellular interaction and multicellular organization. Through previous genetic and EM studies, various extracellular appendages and matrix components have been found to be involved in the social behavior of M. xanthus, but none of them was directly visualized and analyzed under native conditions. Here, we used atomic force microscopy (AFM) imaging and in vivo force spectroscopy to characterize these cellular structures under native conditions. AFM imaging revealed morphological details on the extracellular ultrastructures at an unprecedented resolution, and in vivo force spectroscopy of live cells in fluid allowed us to nanomechanically characterize extracellular polymeric substances. The findings provide the basis for AFM as a useful tool for investigating microbial-surface ultrastructures and nanomechanical properties under native conditions.
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Affiliation(s)
- Andrew E Pelling
- Department of Chemistry and Biochemistry, Institute for Cell Mimetic Space Exploration, University of California, Los Angeles, CA 90095, USA
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Matias VRF, Beveridge TJ. Cryo-electron microscopy reveals native polymeric cell wall structure in Bacillus subtilis 168 and the existence of a periplasmic space. Mol Microbiol 2005; 56:240-51. [PMID: 15773993 DOI: 10.1111/j.1365-2958.2005.04535.x] [Citation(s) in RCA: 188] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Ultrarapid freezing of bacteria (i.e. vitrification) results in optimal preservation of native structure. In this study, cryo-transmission electron microscopy of frozen-hydrated sections was used to gain insight into the organization of the Bacillus subtilis 168 cell envelope. A bipartite structure was seen above the plasma membrane consisting of a low-density 22 nm region above which a higher-density 33 nm region or outer wall zone (OWZ) resided. The interface between these two regions appeared to possess the most mass. In intact and in teichoic acid-extracted wall fragments, only a single region was seen but the mass distribution varied from being dense on the inside to less dense on the outside (i.e. similar to the OWZ). In plasmolysed cells, the inner wall zone (IWZ)'s thickness expanded in size but the OWZ's thickness remained constant. As the IWZ expanded it became filled with plasma membrane vesicles indicating that the IWZ had little substance and was empty of the wall's polymeric network of peptidoglycan and teichoic acid. Together these results strongly suggest that the inner zone actually represents a periplasmic space confined between the plasma membrane and the wall matrix and that the OWZ is the peptidoglycan-teichoic acid polymeric network of the wall.
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Affiliation(s)
- Valério R F Matias
- Biophysics Interdepartmental Group and Department of Microbiology, College of Biological Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1
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Li G, Smith CS, Brun YV, Tang JX. The elastic properties of the caulobacter crescentus adhesive holdfast are dependent on oligomers of N-acetylglucosamine. J Bacteriol 2005; 187:257-65. [PMID: 15601710 PMCID: PMC538810 DOI: 10.1128/jb.187.1.257-265.2005] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The aquatic bacterium Caulobacter crescentus attaches to solid surfaces through an adhesive holdfast located at the tip of its polar stalk, a thin cylindrical extension of the cell membrane. In this paper, the elastic properties of the C. crescentus stalk and holdfast assembly were studied by using video light microscopy. In particular, the contribution of oligomers of N-acetylglucosamine (GlcNAc) to the elasticity of holdfast was examined by lysozyme digestion. C. crescentus cells attached to a surface undergo Brownian motion while confined effectively in a harmonic potential. Mathematical analysis of such motion enabled us to determine the force constant of the stalk-holdfast assembly, which quantifies its elastic properties. The measured force constant exhibits no dependence on stalk length, consistent with the theoretical estimate showing that the stalk can be treated as a rigid rod with respect to fluctuations of the attached cells. Therefore, the force constant of the stalk-holdfast assembly can be attributed to the elasticity of the holdfast. Motions of cells in a rosette were found to be correlated, consistent with the elastic characteristics of the holdfast. Atomic force microscopy analysis indicates that the height of a dried (in air) holdfast is approximately one-third of that of a wet (in water) holdfast, consistent with the gel-like nature of the holdfast. Lysozyme, which cleaves oligomers of GlcNAc, reduced the force constant to less than 10% of its original value, consistent with the polysaccharide gel-like nature of the holdfast. These results also indicate that GlcNAc polymers play an important role in the strength of the holdfast.
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Affiliation(s)
- Guanglai Li
- Physics Department, Brown University, Providence, RI 02912, USA
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Boulbitch A, Quinn B, Pink D. Elasticity of the rod-shaped gram-negative eubacteria. PHYSICAL REVIEW LETTERS 2000; 85:5246-9. [PMID: 11102232 DOI: 10.1103/physrevlett.85.5246] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2000] [Indexed: 05/20/2023]
Abstract
We report a theoretical calculation of the elasticity of the peptidoglycan network, the only stress-bearing part of rod-shaped Gram-negative eubacteria. The peptidoglycan network consists of elastic peptides and inextensible glycan strands, and it has been proposed that the latter form zigzag filaments along the circumference of the cylindrical bacterial shell. The zigzag geometry of the glycan strands gives rise to nonlinear elastic behavior. The four elastic moduli of the peptidoglycan network depend on its stressed state. For a bacterium under physiological conditions the elasticity is proportional to the bacterial turgor pressure. Our results are in good agreement with recent measurements.
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Affiliation(s)
- A Boulbitch
- Department für Biophysik E22, Technische Universität München, James-Franck-Strasse, D-85747 Garching bei München, Germany
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Arnoldi M, Fritz M, Bäuerlein E, Radmacher M, Sackmann E, Boulbitch A. Bacterial turgor pressure can be measured by atomic force microscopy. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 2000; 62:1034-44. [PMID: 11088560 DOI: 10.1103/physreve.62.1034] [Citation(s) in RCA: 188] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/1999] [Indexed: 05/02/2023]
Abstract
We report a study of the deformability of a bacterial wall with an atomic force microscope (AFM). A theoretical expression is derived for the force exerted by the wall on the cantilever as a function of the depths of indentation generated by the AFM tip. Evidence is provided that this reaction force is a measure for the turgor pressure of the bacterium. The method was applied to magnetotactic bacteria of the species Magnetospirillum gryphiswaldense. Force curves were generated on the substrate and on the bacteria while scanning laterally. With the mechanical properties so gained we obtained the spring constant of the bacterium as a whole. Making use of our theoretical results we determined the turgor pressure to be in the range of 85 to 150 kPa.
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Affiliation(s)
- M Arnoldi
- Physik Department, Institut für Biophysik, E22, Technische Universität München, James-Franck-Strasse, 85747 Garching bei München, Germany
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Abstract
The mechanical properties of natural materials as diverse as wood, muscle, shell and bone are plotted on material-property charts which show the relationships between properties. Performance indices are used to identify the load-bearing applications in which each performs particularly well. By these criteria, many natural materials are superior to the man-made materials of engineering. A companion paper examines some of the origins of this superiority; an explanation is sought in an analysis of the way structure influences properties.
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Bacterial templating of ordered macrostructures in silica and silica-surfactant mesophases. Nature 1997. [DOI: 10.1038/385420a0] [Citation(s) in RCA: 482] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Thwaites JJ, Surana UC, Jones AM. Mechanical properties of Bacillus subtilis cell walls: effects of ions and lysozyme. J Bacteriol 1991; 173:204-10. [PMID: 1898921 PMCID: PMC207176 DOI: 10.1128/jb.173.1.204-210.1991] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Bacterial threads of Bacillus subtilis have been immersed in, and redrawn from, water of various pH values, in solutions of (NH4)2SO4 and NaCl of various concentrations, and in lysozyme solutions. The changes in the tensile strength, elastic modulus, and other mechanical properties of the bacterial cell wall due to these treatments were obtained. The data show that change in pH has little effect but that as the salt concentration is increased, the cell walls become more ductile. A high salt concentration (1 M NaCl) can reduce the modulus by a factor of 26 to 13.5 MPa at 81% relative humidity and the strength by a factor of only 2.5. Despite attacking the septal-wall region of the cellular filaments, lysozyme has no effect on the mechanical properties. There is no significant change in the stress relaxation behavior due to any of the treatments. The dependence of mechanical properties on the salt concentration is discussed in terms of the polyelectrolyte nature of cell walls. The evidence presented in this and the accompanying paper (J. J. Thwaites and U.C. Surana, J. Bacteriol., 173:197-203, 1991) supports the idea that the peptidoglycan in bacterial cell wall is an entanglement network with a large degree of molecular flexibility, with some order but no regular structure.
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Affiliation(s)
- J J Thwaites
- Department of Engineering, University of Cambridge, England
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