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Delmarre L, Harté E, Devin A, Argoul P, Argoul F. Two-layer elastic models for single-yeast compressibility with flat microlevers. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2024:10.1007/s00249-024-01710-2. [PMID: 38703210 DOI: 10.1007/s00249-024-01710-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 02/14/2024] [Accepted: 03/20/2024] [Indexed: 05/06/2024]
Abstract
Unicellular organisms such as yeast can survive in very different environments, thanks to a polysaccharide wall that reinforces their extracellular membrane. This wall is not a static structure, as it is expected to be dynamically remodeled according to growth stage, division cycle, environmental osmotic pressure and ageing. It is therefore of great interest to study the mechanics of these organisms, but they are more difficult to study than other mammalian cells, in particular because of their small size (radius of a few microns) and their lack of an adhesion machinery. Using flat cantilevers, we perform compression experiments on single yeast cells (S. cerevisiae) on poly-L-lysine-coated grooved glass plates, in the limit of small deformation using an atomic force microscope (AFM). Thanks to a careful decomposition of force-displacement curves, we extract local scaling exponents that highlight the non-stationary characteristic of the yeast behavior upon compression. Our multi-scale nonlinear analysis of the AFM force-displacement curves provides evidence for non-stationary scaling laws. We propose to model these phenomena based on a two-component elastic system, where each layer follows a different scaling law..
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Affiliation(s)
- L Delmarre
- LOMA, Laboratoire Ondes et Matière d'Aquitaine, CNRS, Université de Bordeaux, Talence, France
| | - E Harté
- LOMA, Laboratoire Ondes et Matière d'Aquitaine, CNRS, Université de Bordeaux, Talence, France
| | - A Devin
- IBGC, Institut de Biologie et Génétique Cellulaire, CNRS, Université de Bordeaux, Bordeaux, France
| | - P Argoul
- LVMT, Ecole des Ponts, Université Gustave Eiffel & MAST-EMGCU, Marne la Vallée, France
| | - F Argoul
- LOMA, Laboratoire Ondes et Matière d'Aquitaine, CNRS, Université de Bordeaux, Talence, France.
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2
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Zhang Y, He W, Wang L, Su W, Chen H, Li A, Chen J. Penetrating the ultra-tough yeast cell wall with finite element analysis model-aided design of microtools. iScience 2024; 27:109503. [PMID: 38591007 PMCID: PMC11000014 DOI: 10.1016/j.isci.2024.109503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 02/27/2024] [Accepted: 03/13/2024] [Indexed: 04/10/2024] Open
Abstract
Microinjecting yeast cells has been challenging for decades with no significant breakthrough due to the ultra-tough cell wall and low stiffness of the traditional injector tip at the micro-scale. Penetrating this protection wall is the key step for artificially bringing foreign substance into the yeast. In this paper, a yeast cell model was built by using finite element analysis (FEA) method to analyze the penetrating process. The key parameters of the yeast cell wall in the model (the Young's modulus, the shear modulus, and the Lame constant) were calibrated according to a general nanoindentation experiment. Then by employing the calibrated model, the injection parameters were optimized to minimize the cell damage (the maximum cell deformation at the critical stress of the cell wall). Key guidelines were suggested for penetrating the cell wall during microinjection.
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Affiliation(s)
- Yanfei Zhang
- School of Mechanical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China
- Shandong Institute of Mechanical Design and Research, Jinan 250353, China
| | - Wende He
- School of Mechanical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China
- Shandong Institute of Mechanical Design and Research, Jinan 250353, China
| | - Li Wang
- School of Mechanical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China
- Shandong Institute of Mechanical Design and Research, Jinan 250353, China
| | - Weiguang Su
- School of Mechanical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China
- Shandong Institute of Mechanical Design and Research, Jinan 250353, China
| | - Hao Chen
- School of Mechanical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China
- Shandong Institute of Mechanical Design and Research, Jinan 250353, China
| | - Anqing Li
- School of Mechanical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China
- Shandong Institute of Mechanical Design and Research, Jinan 250353, China
| | - Jun Chen
- School of Mechanical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China
- Shandong Institute of Mechanical Design and Research, Jinan 250353, China
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3
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Zou J, Peng B, Fan N, Liu Y. Simulation and experimental study on the influence of lamina on nanoneedle penetration into the cell nucleus. Biomech Model Mechanobiol 2024:10.1007/s10237-024-01836-4. [PMID: 38526703 DOI: 10.1007/s10237-024-01836-4] [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: 10/10/2023] [Accepted: 02/21/2024] [Indexed: 03/27/2024]
Abstract
We have developed a finite element model to simulate the penetration of nanoneedles into the cellular nucleus. It is found that the nuclear lamina, the primary supporting structure of the nuclear membrane, plays a crucial role in maintaining the integrity of the nuclear envelope and enhancing stress concentration in the nuclear membrane. Notably, nuclear lamina A exhibits a more pronounced effect compared to nuclear lamina B. Subsequently, we further conducted experiments by controlling the time of osteopontin (OPN) treatment to modify the nuclear lamina density, and the results showed that an increase in nuclear lamina density enhances the probability of nanoneedle penetration into the nuclear membrane. Through employing both simulation and experimental techniques, we have gathered compelling evidence indicating that an augmented density of nuclear lamina A can enhance the penetration of nanoneedles into the nuclear membrane.
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Affiliation(s)
- Jie Zou
- School of Mechatronics Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China
| | - Bei Peng
- School of Mechatronics Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China
| | - Na Fan
- School of Mechatronics Engineering, University of Electronic Science and Technology of China, Chengdu, 611731, China.
| | - Yang Liu
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610065, China.
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4
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Overbeck A, Michel S, Kampen I, Kwade A. Temperature influence on the compression and breakage behaviour of yeast cells. Lett Appl Microbiol 2023; 76:ovad089. [PMID: 37528062 DOI: 10.1093/lambio/ovad089] [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: 02/09/2023] [Revised: 07/13/2023] [Accepted: 07/31/2023] [Indexed: 08/03/2023]
Abstract
Industrial biotechnology uses microbial cells to produce a wide range of products. While the genetic and molecular properties of these organisms are well understood, less is known about their mechanical properties. Previous work has established a test procedure for single yeast cells using a nanoindentation instrument equipped with a flat-punch probe, which allows single cells (Saccharomyces cerevisiae) to be compressed between two parallel surfaces. The resulting force-displacement curves clearly showed the bursting of the cells and were used to determine characteristics such as burst force and burst energy. Other studies have investigated the influence of growth conditions and measurement conditions on the mechanical characteristics. The recent study examined the mechanical characteristics according to the temperature during compression. Temperature from 0°C to 25°C has no significant effect on the micromechanical properties. Increasing the temperature up to 35°C causes a reduction in the strength of the cells. At even higher temperatures, up to 50°C, the burst force and burst energy increase significantly. A deformation geometry model was used to calculate the cell wall tensile strength as a function of temperature. The results of these studies may facilitate the identification of efficient conditions for cell disruption and product recovery in downstream biotechnological processes.
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Affiliation(s)
- Achim Overbeck
- Institute for Particle Technology, Technische Universität Braunschweig, Volkmaroder Straße 5, D-38104 Braunschweig, Germany
| | - Stephanie Michel
- Institute for Particle Technology, Technische Universität Braunschweig, Volkmaroder Straße 5, D-38104 Braunschweig, Germany
| | - Ingo Kampen
- Institute for Particle Technology, Technische Universität Braunschweig, Volkmaroder Straße 5, D-38104 Braunschweig, Germany
| | - Arno Kwade
- Institute for Particle Technology, Technische Universität Braunschweig, Volkmaroder Straße 5, D-38104 Braunschweig, Germany
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5
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Savin N, Erofeev A, Gorelkin P. Analytical Models for Measuring the Mechanical Properties of Yeast. Cells 2023; 12:1946. [PMID: 37566025 PMCID: PMC10417110 DOI: 10.3390/cells12151946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 07/21/2023] [Accepted: 07/26/2023] [Indexed: 08/12/2023] Open
Abstract
The mechanical properties of yeast play an important role in many biological processes, such as cell division and growth, maintenance of internal pressure, and biofilm formation. In addition, the mechanical properties of cells can indicate the degree of damage caused by antifungal drugs, as the mechanical parameters of healthy and damaged cells are different. Over the past decades, atomic force microscopy (AFM) and micromanipulation have become the most widely used methods for evaluating the mechanical characteristics of microorganisms. In this case, the reliability of such an estimate depends on the choice of mathematical model. This review presents various analytical models developed in recent years for studying the mechanical properties of both cells and their individual structures. The main provisions of the applied approaches are described along with their limitations and advantages. Attention is paid to the innovative method of low-invasive nanomechanical mapping with scanning ion-conductance microscopy (SICM), which is currently starting to be successfully used in the discovery of novel drugs acting on the yeast cell wall and plasma membrane.
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Affiliation(s)
- Nikita Savin
- Research Laboratory of Biophysics, National University of Science and Technology MISiS, Moscow 119049, Russia;
| | - Alexander Erofeev
- Research Laboratory of Biophysics, National University of Science and Technology MISiS, Moscow 119049, Russia;
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6
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Han R, Feng XQ, Vollmer W, Stoodley P, Chen J. Deciphering the adaption of bacterial cell wall mechanical integrity and turgor to different chemical or mechanical environments. J Colloid Interface Sci 2023; 640:510-520. [PMID: 36878069 DOI: 10.1016/j.jcis.2023.02.100] [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: 12/28/2022] [Revised: 02/16/2023] [Accepted: 02/19/2023] [Indexed: 02/24/2023]
Abstract
Bacteria adapt the mechanical properties of their cell envelope, including cell wall stiffness, turgor, and cell wall tension and deformation, to grow and survive in harsh environments. However, it remains a technical challenge to simultaneously determine these mechanical properties at a single cell level. Here we combined theoretical modelling with an experimental approach to quantify the mechanical properties and turgor of Staphylococcus epidermidis. It was found that high osmolarity leads to a decrease in both cell wall stiffness and turgor. We also demonstrated that the turgor change is associated with a change in the viscosity of the bacterial cell. We predicted that the cell wall tension is much higher in deionized (DI) water and it decreases with an increase in osmolality. We also found that an external force increases the cell wall deformation to reinforce its adherence to a surface and this effect can be more significant in lower osmolarity. Overall, our work highlights how bacterial mechanics supports survival in harsh environments and uncovers the adaption of bacterial cell wall mechanical integrity and turgor to osmotic and mechanical challenges.
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Affiliation(s)
- Rui Han
- School of Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Xi-Qiao Feng
- Institute of Biomechanics and Medical Engineering, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle upon Tyne NE2 4AX, UK
| | - Paul Stoodley
- Department of Microbial Infection and Immunity and the Department of Orthopaedics, The Ohio State University, Columbus, OH 43210, United States; National Centre for Advanced Tribology at Southampton (nCATS), National Biofilm Innovation Centre (NBIC), Mechanical Engineering, University of Southampton, Southampton S017 1BJ, UK
| | - Jinju Chen
- School of Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU, UK.
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7
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Couttenier E, Bachellier-Bassi S, d'Enfert C, Villard C. Bending stiffness of Candida albicans hyphae as a proxy of cell wall properties. LAB ON A CHIP 2022; 22:3898-3909. [PMID: 36094162 PMCID: PMC9552746 DOI: 10.1039/d2lc00219a] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 05/31/2022] [Indexed: 06/15/2023]
Abstract
The cell wall is a key component of fungi. It constitutes a highly regulated viscoelastic shell which counteracts internal cell turgor pressure. Its mechanical properties thus contribute to define cell morphology. Measurements of the elastic moduli of the fungal cell wall have been carried out in many species including Candida albicans, a major human opportunistic pathogen. They mainly relied on atomic force microscopy, and mostly considered the yeast form. We developed a parallelized pressure-actuated microfluidic device to measure the bending stiffness of hyphae. We found that the cell wall stiffness lies in the MPa range. We then used three different ways to disrupt cell wall physiology: inhibition of beta-glucan synthesis, a key component of the inner cell wall; application of a hyperosmotic shock triggering a sudden decrease of the hyphal diameter; deletion of two genes encoding GPI-modified cell wall proteins resulting in reduced cell wall thickness. The bending stiffness values were affected to different extents by these environmental stresses or genetic modifications. Overall, our results support the elastic nature of the cell wall and its ability to remodel at the scale of the entire hypha over minutes.
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Affiliation(s)
- Elodie Couttenier
- Université PSL, Physico-Chimie Curie, CNRS UMR168, F-75005 Paris, France.
- Institut Pasteur, Université Paris Cité, INRAE, USC2019, Unité Biologie et Pathogénicité Fongiques, F-75015 Paris, France
| | - Sophie Bachellier-Bassi
- Institut Pasteur, Université Paris Cité, INRAE, USC2019, Unité Biologie et Pathogénicité Fongiques, F-75015 Paris, France
| | - Christophe d'Enfert
- Institut Pasteur, Université Paris Cité, INRAE, USC2019, Unité Biologie et Pathogénicité Fongiques, F-75015 Paris, France
| | - Catherine Villard
- Université PSL, Physico-Chimie Curie, CNRS UMR168, F-75005 Paris, France.
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8
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Sinha D, Ivan D, Gibbs E, Chetluru M, Goss J, Chen Q. Fission yeast polycystin Pkd2p promotes cell size expansion and antagonizes the Hippo-related SIN pathway. J Cell Sci 2022; 135:274457. [PMID: 35099006 PMCID: PMC8919332 DOI: 10.1242/jcs.259046] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 01/14/2022] [Indexed: 11/20/2022] Open
Abstract
Polycystins are conserved mechanosensitive channels whose mutations lead to the common human renal disorder autosomal dominant polycystic kidney disease (ADPKD). Previously, we discovered that the plasma membrane-localized fission yeast polycystin homolog Pkd2p is an essential protein required for cytokinesis; however, its role remains unclear. Here, we isolated a novel temperature-sensitive pkd2 mutant, pkd2-B42. Among the strong growth defects of this mutant, the most striking was that many mutant cells often lost a significant portion of their volume in just 5 min followed by a gradual recovery, a process that we termed 'deflation'. Unlike cell lysis, deflation did not result in plasma membrane rupture and occurred independently of cell cycle progression. The tip extension of pkd2-B42 cells was 80% slower than that of wild-type cells, and their turgor pressure was 50% lower. Both pkd2-B42 and the hypomorphic depletion mutant pkd2-81KD partially rescued mutants of the septation initiation network (SIN), a yeast Hippo-related signaling pathway, by preventing cell lysis, enhancing septum formation and doubling the number of Sid2p and Mob1p molecules at the spindle pole bodies. We conclude that Pkd2p promotes cell size expansion during interphase by regulating turgor pressure and antagonizes the SIN during cytokinesis. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Debatrayee Sinha
- Department of Biological Sciences, The University of Toledo, 2801 West Bancroft St, Toledo, OH 43606, USA
| | - Denisa Ivan
- Department of Biological Sciences, The University of Toledo, 2801 West Bancroft St, Toledo, OH 43606, USA
| | - Ellie Gibbs
- Department of Biological Sciences, Wellesley College, 106 Central Street, Wellesley, MA 02482, USA
| | - Madhurya Chetluru
- Department of Biological Sciences, The University of Toledo, 2801 West Bancroft St, Toledo, OH 43606, USA
| | - John Goss
- Department of Biological Sciences, Wellesley College, 106 Central Street, Wellesley, MA 02482, USA
| | - Qian Chen
- Department of Biological Sciences, The University of Toledo, 2801 West Bancroft St, Toledo, OH 43606, USA,Author for correspondence ()
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9
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Gibbs E, Hsu J, Barth K, Goss JW. Characterization of the nanomechanical properties of the fission yeast (Schizosaccharomyces pombe) cell surface by atomic force microscopy. Yeast 2021; 38:480-492. [PMID: 33913187 PMCID: PMC9291503 DOI: 10.1002/yea.3564] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 04/14/2021] [Accepted: 04/23/2021] [Indexed: 11/11/2022] Open
Abstract
Variations in cell wall composition and biomechanical properties can contribute to the cellular plasticity required during complex processes such as polarized growth and elongation in microbial cells. This study utilizes atomic force microscopy (AFM) to map the cell surface topography of fission yeast, Schizosaccharomyces pombe, at the pole regions and to characterize the biophysical properties within these regions under physiological, hydrated conditions. High-resolution images acquired from AFM topographic scanning reveal decreased surface roughness at the cell poles. Force extension curves acquired by nanoindentation probing with AFM cantilever tips under low applied force revealed increased cell wall deformation and decreased cellular stiffness (cellular spring constant) at cell poles (17 ± 4 mN/m) relative to the main body of the cell that is not undergoing growth and expansion (44 ± 10 mN/m). These findings suggest that the increased deformation and decreased stiffness at regions of polarized growth at fission yeast cell poles provide the plasticity necessary for cellular extension. This study provides a direct biophysical characterization of the S. pombe cell surface by AFM, and it provides a foundation for future investigation of how the surface topography and local nanomechanical properties vary during different cellular processes.
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Affiliation(s)
- Ellie Gibbs
- Department of Biological Sciences, Wellesley College, Wellesley, MA, USA
| | - Justine Hsu
- Biochemistry Program, Wellesley College, Wellesley, MA, USA
| | - Kathryn Barth
- Biochemistry Program, Wellesley College, Wellesley, MA, USA
| | - John W Goss
- Department of Biological Sciences, Wellesley College, Wellesley, MA, USA.,Biochemistry Program, Wellesley College, Wellesley, MA, USA
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10
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Beaussart A, Feuillie C, El-Kirat-Chatel S. The microbial adhesive arsenal deciphered by atomic force microscopy. NANOSCALE 2020; 12:23885-23896. [PMID: 33289756 DOI: 10.1039/d0nr07492f] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Microbes employ a variety of strategies to adhere to abiotic and biotic surfaces, as well as host cells. In addition to their surface physicochemical properties (e.g. charge, hydrophobic balance), microbes produce appendages (e.g. pili, fimbriae, flagella) and express adhesion proteins embedded in the cell wall or cell membrane, with adhesive domains targeting specific ligands or chemical properties. Atomic force microscopy (AFM) is perfectly suited to deciphering the adhesive properties of microbial cells. Notably, AFM imaging has revealed the cell wall topographical organization of live cells at unprecedented resolution, and AFM has a dual capability to probe adhesion at the single-cell and single-molecule levels. AFM is thus a powerful tool for unravelling the molecular mechanisms of microbial adhesion at scales ranging from individual molecular interactions to the behaviours of entire cells. In this review, we cover some of the major breakthroughs facilitated by AFM in deciphering the microbial adhesive arsenal, including the exciting development of anti-adhesive strategies.
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11
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Obeid S, Guyomarc'h F. Atomic force microscopy of food assembly: Structural and mechanical insights at the nanoscale and potential opportunities from other fields. FOOD BIOSCI 2020. [DOI: 10.1016/j.fbio.2020.100654] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Krenger R, Burri JT, Lehnert T, Nelson BJ, Gijs MAM. Force microscopy of the Caenorhabditis elegans embryonic eggshell. MICROSYSTEMS & NANOENGINEERING 2020; 6:29. [PMID: 32382445 PMCID: PMC7196560 DOI: 10.1038/s41378-020-0137-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 12/20/2019] [Accepted: 02/13/2020] [Indexed: 05/03/2023]
Abstract
Assays focusing on emerging biological phenomena in an animal's life can be performed during embryogenesis. While the embryo of Caenorhabditis elegans has been extensively studied, its biomechanical properties are largely unknown. Here, we demonstrate that cellular force microscopy (CFM), a recently developed technique that combines micro-indentation with high resolution force sensing approaching that of atomic force microscopy, can be successfully applied to C. elegans embryos. We performed, for the first time, a quantitative study of the mechanical properties of the eggshell of living C. elegans embryos and demonstrate the capability of the system to detect alterations of its mechanical parameters and shell defects upon chemical treatments. In addition to investigating natural eggshells, we applied different eggshell treatments, i.e., exposure to sodium hypochlorite and chitinase solutions, respectively, that selectively modified the multilayer eggshell structure, in order to evaluate the impact of the different layers on the mechanical integrity of the embryo. Finite element method simulations based on a simple embryo model were used to extract characteristic eggshell parameters from the experimental micro-indentation force-displacement curves. We found a strong correlation between the severity of the chemical treatment and the rigidity of the shell. Furthermore, our results showed, in contrast to previous assumptions, that short bleach treatments not only selectively remove the outermost vitelline layer of the eggshell, but also significantly degenerate the underlying chitin layer, which is primarily responsible for the mechanical stability of the egg.
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Affiliation(s)
- Roger Krenger
- Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Jan T. Burri
- Multi-Scale Robotics Laboratory, ETH Zurich, Zürich, 8092 Switzerland
| | - Thomas Lehnert
- Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Bradley J. Nelson
- Multi-Scale Robotics Laboratory, ETH Zurich, Zürich, 8092 Switzerland
| | - Martin A. M. Gijs
- Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
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13
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Goss JW, Volle CB. Using Atomic Force Microscopy To Illuminate the Biophysical Properties of Microbes. ACS APPLIED BIO MATERIALS 2019; 3:143-155. [PMID: 32851362 DOI: 10.1021/acsabm.9b00973] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Since its invention in 1986, atomic force microscopy (AFM) has grown from a system designed for imaging inorganic surfaces to a tool used to probe the biophysical properties of living cells and tissues. AFM is a scanning probe technique and uses a pyramidal tip attached to a flexible cantilever to scan across a surface, producing a highly detailed image. While many research articles include AFM images, fewer include force-distance curves, from which several biophysical properties can be determined. In a single force-distance curve, the cantilever is lowered and raised from the surface, while the forces between the tip and the surface are monitored. Modern AFM has a wide variety of applications, but this review will focus on exploring the mechanobiology of microbes, which we believe is of particular interest to those studying biomaterials. We briefly discuss experimental design as well as different ways of extracting meaningful values related to cell surface elasticity, cell stiffness, and cell adhesion from force-distance curves. We also highlight both classic and recent experiments using AFM to illuminate microbial biophysical properties.
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Affiliation(s)
- John W Goss
- Department of Biological Sciences, Wellesley College, Wellesley, Massachusetts 02481, United States
| | - Catherine B Volle
- Departments of Biology and Chemistry, Cornell College, Mount Vernon, Iowa 52314, United States
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14
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Beaussart A, El-Kirat-Chatel S. Microbial adhesion and ultrastructure from the single-molecule to the single-cell levels by Atomic Force Microscopy. Cell Surf 2019; 5:100031. [PMID: 32743147 PMCID: PMC7389263 DOI: 10.1016/j.tcsw.2019.100031] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 07/04/2019] [Accepted: 07/05/2019] [Indexed: 12/29/2022] Open
Abstract
In the last decades, atomic force microscopy (AFM) has evolved towards an accurate and lasting tool to study the surface of living cells in physiological conditions. Through imaging, single-molecule force spectroscopy and single-cell force spectroscopy modes, AFM allows to decipher at multiple scales the morphology and the molecular interactions taking place at the cell surface. Applied to microbiology, these approaches have been used to elucidate biophysical properties of biomolecules and to directly link the molecular structures to their function. In this review, we describe the main methods developed for AFM-based microbial surface analysis that we illustrate with examples of molecular mechanisms unravelled with unprecedented resolution.
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15
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Cárdenas-Pérez S, Chanona-Pérez JJ, Méndez-Méndez JV, Arzate-Vázquez I, Hernández-Varela JD, Vera NG. Recent advances in atomic force microscopy for assessing the nanomechanical properties of food materials. Trends Food Sci Technol 2019. [DOI: 10.1016/j.tifs.2018.04.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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16
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Ditscherlein L, Jolan Gulden S, Müller S, Baumann RP, Peuker UA, Nirschl H. Measuring interactions between yeast cells and a micro-sized air bubble via atomic force microscopy. J Colloid Interface Sci 2018; 532:689-699. [DOI: 10.1016/j.jcis.2018.08.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 08/08/2018] [Accepted: 08/09/2018] [Indexed: 11/28/2022]
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17
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Lavaisse LM, Hollmann A, Nazareno MA, Disalvo EA. Zeta potential changes of Saccharomyces cerevisiae during fermentative and respiratory cycles. Colloids Surf B Biointerfaces 2018; 174:63-69. [PMID: 30439639 DOI: 10.1016/j.colsurfb.2018.11.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 10/31/2018] [Accepted: 11/01/2018] [Indexed: 01/31/2023]
Abstract
Saccharomyces cerevisiae is a type of yeast, widely used in diverse biotechnological food-beverage processes. Although the performance of an industrial fermentation process depends largely on the number of cells, it is necessary to consider the physiological state of the cultures. In this context, the aim of this study was to determine in a yeast culture how factors such as growth conditions affect surface properties at the different growth stages. Our results show that, S. cerevisiae spp. exhibits different zeta potential mean values along the exponential, post-diauxic and stationary growth phases. In addition, there were differences depending on whether they are in aerobic or anaerobic conditions. When the effect of pH on the media was studied, a different dependence of zeta potential at each stage reveals that in the living cells the surface potential depends on the interaction between secreted acids and the constituents of the surfaces, according to the growth conditions. In order to have a view at the cellular level, the zeta potential on individual cells by optical microscopy has been determined at different stages of culture in aerobic and anaerobic conditions. This single-cell method allows for the identification and following of the development of different cell subpopulations during each growth stage. Furthermore, the behavior of the dead cells provided evidence to relate the large negatively charged population with cell wall damage. Overall, the results obtained in the present work represent an important milestone for a novel application of zeta potential technique on yeast.
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Affiliation(s)
- Lucía M Lavaisse
- Laboratory of Applied Biophysics, CIBAAL - National University of Santiago del Estero and CONICET, 4206, RN 9 Km 1125, Santiago del Estero, Argentina; Laboratory of Antioxidants and Oxidative Process, Institute of Chemical Sciences, Faculty of Agronomy and Agroindustries, National University of Santiago del Estero and CONICET, 4206, RN 9 Km 1125, Santiago del Estero, Argentina
| | - Axel Hollmann
- Laboratory of Bioactive Compounds, CIBAAL - National University of Santiago del Estero and CONICET, 4206, RN 9 Km 1125, Santiago del Estero, Argentina; Laboratory of Molecular Microbiology, Institute of Basic and Applied Microbiology, National University of Quilmes, B1876BXD Bernal, Argentina.
| | - Mónica A Nazareno
- Laboratory of Antioxidants and Oxidative Process, Institute of Chemical Sciences, Faculty of Agronomy and Agroindustries, National University of Santiago del Estero and CONICET, 4206, RN 9 Km 1125, Santiago del Estero, Argentina
| | - Edgardo A Disalvo
- Laboratory of Applied Biophysics, CIBAAL - National University of Santiago del Estero and CONICET, 4206, RN 9 Km 1125, Santiago del Estero, Argentina
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18
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Gulyuk AV, LaJeunesse DR, Collazo R, Ivanisevic A. Characterization of Pseudomonas aeruginosa Films on Different Inorganic Surfaces before and after UV Light Exposure. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:10806-10815. [PMID: 30122052 DOI: 10.1021/acs.langmuir.8b02079] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The changes of the surface properties of Au, GaN, and SiO x after UV light irradiation were used to actively influence the process of formation of Pseudomonas aeruginosa films. The interfacial properties of the substrates were characterized by X-ray photoelectron spectroscopy and atomic force microscopy. The changes in the P. aeruginosa film properties were accessed by analyzing adhesion force maps and quantifying the intracellular Ca2+ concentration. The collected analysis indicates that the alteration of the inorganic materials' surface chemistry can lead to differences in biofilm formation and variable response from P. aeruginosa cells.
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Affiliation(s)
- Alexey V Gulyuk
- Department of Materials Science and Engineering , North Carolina State University , Raleigh , North Carolina 27695 , United States
| | - Dennis R LaJeunesse
- Joint School of Nanoscience and Nanoengineering , University of North Carolina-Greensboro and North Carolina A&T State University , Greensboro , North Carolina 27401 , United States
| | - Ramon Collazo
- Department of Materials Science and Engineering , North Carolina State University , Raleigh , North Carolina 27695 , United States
| | - Albena Ivanisevic
- Department of Materials Science and Engineering , North Carolina State University , Raleigh , North Carolina 27695 , United States
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19
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Vella D, Davidovitch B. Regimes of wrinkling in an indented floating elastic sheet. Phys Rev E 2018; 98:013003. [PMID: 30110841 DOI: 10.1103/physreve.98.013003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Indexed: 06/08/2023]
Abstract
A thin, elastic sheet floating on the surface of a liquid bath wrinkles when poked at its center. We study the onset of wrinkling as well as the evolution of the pattern as indentation progresses far beyond the wrinkling threshold. We use tension field theory to describe the macroscopic properties of the deformed film and show that the system passes through a host of different regimes, even while the deflections and strains remain small. We show that the effect of the finite size of the sheet ultimately plays a key role in determining the location of the wrinkle pattern, and obtain scaling relations that characterize the number of wrinkles at threshold and its variation as the indentation progresses.
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Affiliation(s)
- Dominic Vella
- Mathematical Institute, University of Oxford, Woodstock Road, Oxford OX2 6GG, United Kingdom
| | - Benny Davidovitch
- Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003, USA
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20
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Schiavone M, Déjean S, Sieczkowski N, Castex M, Dague E, François JM. Integration of Biochemical, Biophysical and Transcriptomics Data for Investigating the Structural and Nanomechanical Properties of the Yeast Cell Wall. Front Microbiol 2017; 8:1806. [PMID: 29085340 PMCID: PMC5649194 DOI: 10.3389/fmicb.2017.01806] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 09/05/2017] [Indexed: 11/24/2022] Open
Abstract
The yeast cell is surrounded by a cell wall conferring protection and resistance to environmental conditions that can be harmful. Identify the molecular cues (genes) which shape the biochemical composition and the nanomechanical properties of the cell wall and the links between these two parameters represent a major issue in the understanding of the biogenesis and the molecular assembly of this essential cellular structure, which may have consequences in diverse biotechnological applications. We addressed this question in two ways. Firstly, we compared the biochemical and biophysical properties using atomic force microscopy (AFM) methods of 4 industrial strains with the laboratory sequenced strain BY4743 and used transcriptome data of these strains to infer biological hypothesis about differences of these properties between strains. This comparative approach showed a 4–6-fold higher hydrophobicity of industrial strains that was correlated to higher expression of genes encoding adhesin and adhesin-like proteins and not to their higher mannans content. The second approach was to employ a multivariate statistical analysis to identify highly correlated variables among biochemical, biophysical and genes expression data. Accordingly, we found a tight association between hydrophobicity and adhesion events that positively correlated with a set of 22 genes in which the main enriched GO function was the sterol metabolic process. We also identified a strong association of β-1,3-glucans with contour length that corresponds to the extension of mannans chains upon pulling the mannosyl units with the lectin-coated AFM tips. This association was positively correlated with a group of 27 genes in which the seripauperin multigene family was highly documented and negatively connected with a set of 23 genes whose main GO biological process was sulfur assimilation/cysteine biosynthetic process. On the other hand, the elasticity modulus was found weakly associated with levels of β-1,6-glucans, and this biophysical variable was positively correlated with a set of genes implicated in microtubules polymerization, tubulin folding and mitotic organization.
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Affiliation(s)
- Marion Schiavone
- Laboratoire d'Ingénierie des Systèmes Biologiques et Procédés, Institut National des Sciences Appliquées de Toulouse, UPS, INP, Université de ToulouseToulouse, France.,Lallemand SASBlagnac, France
| | | | | | | | - Etienne Dague
- Laboratoire D'analyse et D'architecture des Systèmes du-Centre National de la Recherche Scientifique, Université de ToulouseToulouse, France
| | - Jean M François
- Laboratoire d'Ingénierie des Systèmes Biologiques et Procédés, Institut National des Sciences Appliquées de Toulouse, UPS, INP, Université de ToulouseToulouse, France
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21
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Barazani B, Warnat S, MacIntosh AJ, Hubbard T. MEMS measurements of single cell stiffness decay due to cyclic mechanical loading. Biomed Microdevices 2017; 19:77. [PMID: 28842775 DOI: 10.1007/s10544-017-0219-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The goal of this study was to measure the mechanical stiffness of individual cells and to observe changes due to the application of repeated cell mechanical loads. 28 single baker's yeast cells (Saccharomyces cerevisiae) were fatigue tested and had their stiffness measured during repetitive loading cycles performed by a MEMS squeezer in aqueous media. Electrothermal micro-actuators compressed individual cells against a reference back spring; cell and spring motions were measured using a FFT image analysis technique with ~10 nm resolution. Cell stiffness was calculated based on measurements of cell elongation vs. applied force which resulted in stiffness values in the 2-10 N/m range. The effect of increased force was studied for cells mechanically cycled 37 times. Cell stiffness decreased as the force and the cycle number increased. After 37 loading cycles (~4 min), forces of 0.24, 0.29, 0.31, and 0.33 μN caused stiffness drops of 5%, 13%, 31% and 41% respectively. Cells force was then set to 0.29 μN and cells were tested over longer runs of 118 and 268 cycles. After 118 cycles (~12 min) cells experienced an average stiffness drop of 68%. After 268 cycles (~25 min) cells had a stiffness drop of 77%, and appeared to reach a stiffness plateau of 20-25% of the initial stiffness after approximately 200 cycles.
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Affiliation(s)
- Bruno Barazani
- Mechanical Engineering Department, Dalhousie University, Halifax, NS, B3H 4R2, Canada
| | - Stephan Warnat
- Mechanical & Industrial Engineering Department, Montana State University, Bozeman, MT, 59717-3800, USA
| | - Andrew J MacIntosh
- Food Science and Human Nutrition Department, University of Florida, Gainesville, FL, 32611-0370, USA
| | - Ted Hubbard
- Mechanical Engineering Department, Dalhousie University, Halifax, NS, B3H 4R2, Canada.
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22
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Overbeck A, Günther S, Kampen I, Kwade A. Compression Testing and Modeling of Spherical Cells - Comparison of Yeast and Algae. Chem Eng Technol 2017. [DOI: 10.1002/ceat.201600145] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Achim Overbeck
- Technische Universität Braunschweig; Institute for Particle Technology; Volkmaroder Str. 5 38104 Braunschweig Germany
| | - Steffi Günther
- Technische Universität Braunschweig; Institute for Particle Technology; Volkmaroder Str. 5 38104 Braunschweig Germany
| | - Ingo Kampen
- Technische Universität Braunschweig; Institute for Particle Technology; Volkmaroder Str. 5 38104 Braunschweig Germany
- Technische Universität Braunschweig; PVZ - Center of Pharmaceutical Engineering; Franz-Liszt-Strasse 35a 38106 Braunschweig Germany
| | - Arno Kwade
- Technische Universität Braunschweig; Institute for Particle Technology; Volkmaroder Str. 5 38104 Braunschweig Germany
- Technische Universität Braunschweig; PVZ - Center of Pharmaceutical Engineering; Franz-Liszt-Strasse 35a 38106 Braunschweig Germany
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23
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24
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Goldenbogen B, Giese W, Hemmen M, Uhlendorf J, Herrmann A, Klipp E. Dynamics of cell wall elasticity pattern shapes the cell during yeast mating morphogenesis. Open Biol 2016; 6:160136. [PMID: 27605377 PMCID: PMC5043577 DOI: 10.1098/rsob.160136] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 08/08/2016] [Indexed: 12/17/2022] Open
Abstract
The cell wall defines cell shape and maintains integrity of fungi and plants. When exposed to mating pheromone, Saccharomyces cerevisiae grows a mating projection and alters in morphology from spherical to shmoo form. Although structural and compositional alterations of the cell wall accompany shape transitions, their impact on cell wall elasticity is unknown. In a combined theoretical and experimental approach using finite-element modelling and atomic force microscopy (AFM), we investigated the influence of spatially and temporally varying material properties on mating morphogenesis. Time-resolved elasticity maps of shmooing yeast acquired with AFM in vivo revealed distinct patterns, with soft material at the emerging mating projection and stiff material at the tip. The observed cell wall softening in the protrusion region is necessary for the formation of the characteristic shmoo shape, and results in wider and longer mating projections. The approach is generally applicable to tip-growing fungi and plants cells.
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Affiliation(s)
- Björn Goldenbogen
- Theoretical Biophysics, Institute of Biology, Humboldt-Universität zu Berlin, Invalidenstraße 42, 10115 Berlin, Germany
| | - Wolfgang Giese
- Theoretical Biophysics, Institute of Biology, Humboldt-Universität zu Berlin, Invalidenstraße 42, 10115 Berlin, Germany
| | - Marie Hemmen
- Theoretical Biophysics, Institute of Biology, Humboldt-Universität zu Berlin, Invalidenstraße 42, 10115 Berlin, Germany
| | - Jannis Uhlendorf
- Theoretical Biophysics, Institute of Biology, Humboldt-Universität zu Berlin, Invalidenstraße 42, 10115 Berlin, Germany
| | - Andreas Herrmann
- Molecular Biophysics, Institute of Biology, Humboldt-Universität zu Berlin, Invalidenstraße 42, 10115 Berlin, Germany
| | - Edda Klipp
- Theoretical Biophysics, Institute of Biology, Humboldt-Universität zu Berlin, Invalidenstraße 42, 10115 Berlin, Germany
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25
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Overbeck A, Kampen I, Kwade A. Mechanical characterization of yeast cells: effects of growth conditions. Lett Appl Microbiol 2015; 61:333-8. [PMID: 26189650 DOI: 10.1111/lam.12468] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 05/03/2015] [Accepted: 07/01/2015] [Indexed: 12/01/2022]
Abstract
UNLABELLED Industrial biotechnology uses microbiological cells to produce a wide range of products. While the organisms in question are well understood regarding their genetic and molecular properties, less is known about their mechanical properties. Previous work has established a testing procedure for single Saccharomyces cerevisiae cells using a Nanoindenter equipped with a Flat Punch probe, allowing the compression between two parallel surfaces. The resulting force-displacement curves clearly showed the bursting of the cells and served to determine characteristic values such as the bursting force, bursting energy and relative deformation. This study examined the mechanical characteristics of yeast cells under the influence of varying cultivation parameters, namely the pH value, temperature, aeration rate, stirrer speed and culture medium composition. It was observed that only temperature and medium composition showed significant effect on the mechanical properties of the cells. Higher temperatures during cultivation caused lower bursting forces and energies. Further analysis of the data showed that the mechanical characteristics of the cells were only influenced by parameters which also had an influence on the growth rate. In conclusion, higher growth rates result in a lower mechanical strength of the yeast cells. SIGNIFICANCE AND IMPACT OF THE STUDY This study provides data on the influence of growth conditions on the mechanical properties of yeast cells. Single cell compression tests on Saccharomyces cerevisiae cells indicate that higher growth rates result in a lower mechanical strength of the cells. As in biotechnological processes mechanical degradation is often part of the downstream process to release the product from the micro-organisms, the knowledge about the mechanical properties of the cells is relevant for process optimization.
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Affiliation(s)
- A Overbeck
- Institute for Particle Technology, Technische Universität Braunschweig, Braunschweig, Germany
| | - I Kampen
- Institute for Particle Technology, Technische Universität Braunschweig, Braunschweig, Germany
| | - A Kwade
- Institute for Particle Technology, Technische Universität Braunschweig, Braunschweig, Germany
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26
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Sosale NG, Spinler KR, Alvey C, Discher DE. Macrophage engulfment of a cell or nanoparticle is regulated by unavoidable opsonization, a species-specific 'Marker of Self' CD47, and target physical properties. Curr Opin Immunol 2015; 35:107-12. [PMID: 26172292 DOI: 10.1016/j.coi.2015.06.013] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 06/24/2015] [Indexed: 02/04/2023]
Abstract
Professional phagocytes of the mononuclear phagocyte system (MPS), especially ubiquitous macrophages, are commonly thought to engulf or not a target based strictly on 'eat me' molecules such as Antibodies. The target might be a viable 'self' cell or a drug-delivering nanoparticle, or it might be a cancer cell or a microbe. 'Marker of Self' CD47 signals into a macrophage to inhibit the acto-myosin cytoskeleton that makes engulfment efficient. In adhesion of any cell, the same machinery is generally activated by rigidity of target surfaces, and recent results confirm phagocytosis is likewise driven by the rigidity typical of microbes and many synthetics. Basic insights are already being applied in order to make macrophages eat cancer or to delay nanoparticle clearance for better drug delivery and imaging.
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Affiliation(s)
- Nisha G Sosale
- Molecular & Cell Biophysics and NanoBioPolymers Labs, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Kyle R Spinler
- Molecular & Cell Biophysics and NanoBioPolymers Labs, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Cory Alvey
- Molecular & Cell Biophysics and NanoBioPolymers Labs, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Dennis E Discher
- Molecular & Cell Biophysics and NanoBioPolymers Labs, University of Pennsylvania, Philadelphia, PA 19104, United States.
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27
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Dover RS, Bitler A, Shimoni E, Trieu-Cuot P, Shai Y. Multiparametric AFM reveals turgor-responsive net-like peptidoglycan architecture in live streptococci. Nat Commun 2015; 6:7193. [PMID: 26018339 PMCID: PMC4458890 DOI: 10.1038/ncomms8193] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2015] [Accepted: 04/16/2015] [Indexed: 12/13/2022] Open
Abstract
Cell-wall peptidoglycan (PG) of Gram-positive bacteria is a strong and elastic multi-layer designed to resist turgor pressure and determine the cell shape and growth. Despite its crucial role, its architecture remains largely unknown. Here using high-resolution multiparametric atomic force microscopy (AFM), we studied how the structure and elasticity of PG change when subjected to increasing turgor pressure in live Group B Streptococcus. We show a new net-like arrangement of PG, which stretches and stiffens following osmotic challenge. The same structure also exists in isogenic mutants lacking surface appendages. Cell aging does not alter the elasticity of the cell wall, yet destroys the net architecture and exposes single segmented strands with the same circumferential orientation as predicted for intact glycans. Together, we show a new functional PG architecture in live Gram-positive bacteria. The peptidoglycan (PG) layer of the Gram-positive bacteria cell wall resists turgor pressure, but the architecture of this layer is largely unknown. Here the authors use high resolution atomic force microscopy to image the PG layer from live Streptococcus to reveal a net-like arrangement that resists osmotic challenge by stretching and stiffening.
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Affiliation(s)
- Ron Saar Dover
- Department of Biological Chemistry, 8 Ulman Building, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Arkady Bitler
- Department of Chemical Research Support, Surface Analysis Unit, Goldwurm Building, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Eyal Shimoni
- Department of Chemical Research Support, Electron Microscopy Unit, Issac Wolfson Building, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Patrick Trieu-Cuot
- Department of Microbiology, Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram-Positif, CNRS ERL3526, Paris 75015, France
| | - Yechiel Shai
- Department of Biological Chemistry, 8 Ulman Building, The Weizmann Institute of Science, Rehovot 76100, Israel
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28
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Vella D, Huang J, Menon N, Russell TP, Davidovitch B. Indentation of ultrathin elastic films and the emergence of asymptotic isometry. PHYSICAL REVIEW LETTERS 2015; 114:014301. [PMID: 25615471 DOI: 10.1103/physrevlett.114.014301] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Indexed: 05/16/2023]
Abstract
We study the indentation of a thin elastic film floating at the surface of a liquid. We focus on the onset of radial wrinkles at a threshold indentation depth and the evolution of the wrinkle pattern as indentation progresses far beyond this threshold. Comparison between experiments on thin polymer films and theoretical calculations shows that the system very quickly reaches the far from threshold regime, in which wrinkles lead to the relaxation of azimuthal compression. Furthermore, when the indentation depth is sufficiently large that the wrinkles cover most of the film, we recognize a novel mechanical response in which the work of indentation is transmitted almost solely to the liquid, rather than to the floating film. We attribute this unique response to a nontrivial isometry attained by the deformed film, and we discuss the scaling laws and the relevance of similar isometries to other systems in which a confined sheet is subjected to weak tensile loads.
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Affiliation(s)
- Dominic Vella
- Mathematical Institute, University of Oxford, Oxford OX2 6GG, United Kingdom
| | - Jiangshui Huang
- Physics Department, University of Massachusetts, Amherst, Massachusetts 01003, USA and Polymer Science and Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - Narayanan Menon
- Physics Department, University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - Thomas P Russell
- Polymer Science and Engineering Department, University of Massachusetts, Amherst, Massachusetts 01003, USA
| | - Benny Davidovitch
- Physics Department, University of Massachusetts, Amherst, Massachusetts 01003, USA
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29
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Lu S, Walters G, Parg R, Dutcher JR. Nanomechanical response of bacterial cells to cationic antimicrobial peptides. SOFT MATTER 2014; 10:1806-1815. [PMID: 24652481 DOI: 10.1039/c3sm52801d] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The effectiveness of antimicrobial compounds can be easily screened, however their mechanism of action is much more difficult to determine. Many compounds act by compromising the mechanical integrity of the bacterial cell envelope, and our study introduces an AFM-based creep deformation technique to evaluate changes in the time-dependent mechanical properties of Pseudomonas aeruginosa PAO1 bacterial cells upon exposure to two different but structurally related antimicrobial peptides. We observed a distinctive signature for the loss of integrity of the bacterial cell envelope following exposure to the peptides. Measurements performed before and after exposure, as well as time-resolved measurements and those performed at different concentrations, revealed large changes to the viscoelastic parameters that are consistent with differences in the membrane permeabilizing effects of the peptides. The AFM creep deformation measurement provides new, unique insight into the kinetics and mechanism of action of antimicrobial peptides on bacteria.
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Affiliation(s)
- Shun Lu
- Department of Physics, University of Guelph, Guelph, N1G 2W1, Ontario, Canada.
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30
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Ebrahimi H, Ajdari A, Vella D, Boudaoud A, Vaziri A. Anisotropic blistering instability of highly ellipsoidal shells. PHYSICAL REVIEW LETTERS 2014; 112:094302. [PMID: 24655258 DOI: 10.1103/physrevlett.112.094302] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Indexed: 06/03/2023]
Abstract
The formation of localized periodic structures in the deformation of elastic shells is well documented and is a familiar first stage in the crushing of a spherical shell such as a ping-pong ball. While spherical shells manifest such periodic structures as polygons, we present a new instability that is observed in the indentation of a highly ellipsoidal shell by a horizontal plate. Above a critical indentation depth, the plate loses contact with the shell in a series of well-defined "blisters" along the long axis of the ellipsoid. We characterize the onset of this instability and explain it using scaling arguments, numerical simulations, and experiments. We also characterize the properties of the blistering pattern by showing how the number of blisters and their size depend on both the geometrical properties of the shell and the indentation but not on the shell's elastic modulus. This blistering instability may be used to determine the thickness of highly ellipsoidal shells simply by squashing them between two plates.
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Affiliation(s)
- Hamid Ebrahimi
- Department of Mechanical and Industrial Engineering, Northeastern University, Boston, Massachusetts 02115, USA
| | - Amin Ajdari
- Department of Mechanical Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Dominic Vella
- Mathematical Institute, University of Oxford,Woodstock Road, Oxford OX2 6GG, United Kingdom
| | - Arezki Boudaoud
- Laboratoire Reproduction et Développement des Plantes & Laboratoire Joliot-Curie, INRA, CNRS, ENS, Université de Lyon, 46 Allée d'Italie, F-69364 Lyon Cedex 07, France
| | - Ashkan Vaziri
- Department of Mechanical and Industrial Engineering, Northeastern University, Boston, Massachusetts 02115, USA
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31
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Knoche S, Vella D, Aumaitre E, Degen P, Rehage H, Cicuta P, Kierfeld J. Elastometry of deflated capsules: elastic moduli from shape and wrinkle analysis. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:12463-12471. [PMID: 24015876 DOI: 10.1021/la402322g] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Elastic capsules, prepared from droplets or bubbles attached to a capillary (as in a pendant drop tensiometer), can be deflated by suction through the capillary. We study this deflation and show that a combined analysis of the shape and wrinkling characteristics enables us to determine the elastic properties in situ. Shape contours are analyzed and fitted using shape equations derived from nonlinear membrane-shell theory to give the elastic modulus, Poisson ratio and stress distribution of the membrane. We include wrinkles, which generically form upon deflation, within the shape analysis. Measuring the wavelength of wrinkles and using the calculated stress distribution gives the bending stiffness of the membrane. We compare this method with previous approaches using the Laplace-Young equation and illustrate the method on two very different capsule materials: polymerized octadecyltrichlorosilane (OTS) capsules and hydrophobin (HFBII) coated bubbles. Our results are in agreement with the available rheological data. For hydrophobin coated bubbles, the method reveals an interesting nonlinear behavior consistent with the hydrophobin molecules having a rigid core surrounded by a softer shell.
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Affiliation(s)
- Sebastian Knoche
- Department of Physics, Technische Universität Dortmund , 44221 Dortmund, Germany
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32
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Mechanical double layer model for Saccharomyces Cerevisiae cell wall. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2013; 42:613-20. [DOI: 10.1007/s00249-013-0909-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 04/22/2013] [Accepted: 04/23/2013] [Indexed: 01/30/2023]
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33
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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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Otero J, Baños R, González L, Torrents E, Juárez A, Puig-Vidal M. Quartz tuning fork studies on the surface properties of Pseudomonas aeruginosa during early stages of biofilm formation. Colloids Surf B Biointerfaces 2013; 102:117-23. [DOI: 10.1016/j.colsurfb.2012.08.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2012] [Revised: 07/19/2012] [Accepted: 08/07/2012] [Indexed: 11/29/2022]
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Chaudhari R, Stenson J, Overton T, Thomas C. Effect of bud scars on the mechanical properties of Saccharomyces cerevisiae cell walls. Chem Eng Sci 2012. [DOI: 10.1016/j.ces.2012.08.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Vella D, Ajdari A, Vaziri A, Boudaoud A. Indentation of ellipsoidal and cylindrical elastic shells. PHYSICAL REVIEW LETTERS 2012; 109:144302. [PMID: 23083246 DOI: 10.1103/physrevlett.109.144302] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Indexed: 05/02/2023]
Abstract
Thin shells are found in nature at scales ranging from viruses to hens' eggs; the stiffness of such shells is essential for their function. We present the results of numerical simulations and theoretical analyses for the indentation of ellipsoidal and cylindrical elastic shells, considering both pressurized and unpressurized shells. We provide a theoretical foundation for the experimental findings of Lazarus et al. [following paper, Phys. Rev. Lett. 109, 144301 (2012)] and for previous work inferring the turgor pressure of bacteria from measurements of their indentation stiffness; we also identify a new regime at large indentation. We show that the indentation stiffness of convex shells is dominated by either the mean or Gaussian curvature of the shell depending on the pressurization and indentation depth. Our results reveal how geometry rules the rigidity of shells.
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Affiliation(s)
- Dominic Vella
- OCCAM, Mathematical Institute, University of Oxford, 24-29 St Giles', Oxford, OX1 3LB, United Kingdom
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Krull R, Wucherpfennig T, Esfandabadi ME, Walisko R, Melzer G, Hempel DC, Kampen I, Kwade A, Wittmann C. Characterization and control of fungal morphology for improved production performance in biotechnology. J Biotechnol 2012; 163:112-23. [PMID: 22771505 DOI: 10.1016/j.jbiotec.2012.06.024] [Citation(s) in RCA: 136] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 05/02/2012] [Accepted: 06/25/2012] [Indexed: 11/25/2022]
Abstract
Filamentous fungi have been widely applied in industrial biotechnology for many decades. In submerged culture processes, they typically exhibit a complex morphological life cycle that is related to production performance--a link that is of high interest for process optimization. The fungal forms can vary from dense spherical pellets to viscous mycelia. The resulting morphology has been shown to be influenced strongly by process parameters, including power input through stirring and aeration, mass transfer characteristics, pH value, osmolality and the presence of solid micro-particles. The surface properties of fungal spores and hyphae also play a role. Due to their high industrial relevance, the past years have seen a substantial development of tools and techniques to characterize the growth of fungi and obtain quantitative estimates on their morphological properties. Based on the novel insights available from such studies, more recent studies have been aimed at the precise control of morphology, i.e., morphology engineering, to produce superior bio-processes with filamentous fungi.
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Affiliation(s)
- Rainer Krull
- Institute of Biochemical Engineering, Technische Universität Braunschweig, Germany.
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Vella D, Ajdari A, Vaziri A, Boudaoud A. Wrinkling of pressurized elastic shells. PHYSICAL REVIEW LETTERS 2011; 107:174301. [PMID: 22107521 DOI: 10.1103/physrevlett.107.174301] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Revised: 08/30/2011] [Indexed: 05/28/2023]
Abstract
We study the formation of localized structures formed by the point loading of an internally pressurized elastic shell. While unpressurized shells (such as a ping-pong ball) buckle into polygonal structures, we show that pressurized shells are subject to a wrinkling instability. We study wrinkling in depth, presenting scaling laws for the critical indentation at which wrinkling occurs and the number of wrinkles formed in terms of the internal pressurization and material properties of the shell. These results are validated by numerical simulations. We show that the evolution of the wrinkle length with increasing indentation can be understood for highly pressurized shells from membrane theory. These results suggest that the position and number of wrinkles may be used in combination to give simple methods for the estimation of the mechanical properties of highly pressurized shells.
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Affiliation(s)
- Dominic Vella
- OCCAM, Mathematical Institute, University of Oxford, 24-29 St Giles', Oxford, OX1 3LB, United Kingdom
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Vella D, Ajdari A, Vaziri A, Boudaoud A. The indentation of pressurized elastic shells: from polymeric capsules to yeast cells. J R Soc Interface 2011; 9:448-55. [PMID: 21831894 DOI: 10.1098/rsif.2011.0352] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Pressurized elastic capsules arise at scales ranging from the 10 m diameter pressure vessels used to store propane at oil refineries to the microscopic polymeric capsules that may be used in drug delivery. Nature also makes extensive use of pressurized elastic capsules: plant cells, bacteria and fungi have stiff walls, which are subject to an internal turgor pressure. Here, we present theoretical, numerical and experimental investigations of the indentation of a linearly elastic shell subject to a constant internal pressure. We show that, unlike unpressurized shells, the relationship between force and displacement demonstrates two linear regimes. We determine analytical expressions for the effective stiffness in each of these regimes in terms of the material properties of the shell and the pressure difference. As a consequence, a single indentation experiment over a range of displacements may be used as a simple assay to determine both the internal pressure and elastic properties of capsules. Our results are relevant for determining the internal pressure in bacterial, fungal or plant cells. As an illustration of this, we apply our results to recent measurements of the stiffness of baker's yeast and infer from these experiments that the internal osmotic pressure of yeast cells may be regulated in response to changes in the osmotic pressure of the external medium.
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Affiliation(s)
- Dominic Vella
- Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, UK.
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Affiliation(s)
- Yuqing Lin
- Department of Chemistry, University of Gothenburg, S-41296, Gothenburg, Sweden
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Current awareness on yeast. Yeast 2010. [DOI: 10.1002/yea.1724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Thomas CR, Stenson JD, Zhang Z. Measuring the mechanical properties of single microbial cells. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2010; 124:83-98. [PMID: 21072700 DOI: 10.1007/10_2010_84] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Many cells are considered to be susceptible to mechanical forces or "shear" in bioprocessing, leading to undesirable cell breakage or adverse metabolic effects. However, cell breakage is the aim of some processing operations, in particular high-pressure homogenisation and other cell disruption methods. In either case, the exact mechanisms of damage or disruption are obscure. One reason for this is that the mechanical properties of the cells are generally unknown, which makes investigation or prediction of the damage difficult. There are several methods for measuring the mechanical properties of single microbial cells, and these are reviewed briefly. In the context of bioprocessing research, a powerful method of characterising the mechanical properties of single cells is compression testing using micromanipulation, supplemented by mathematical modelling of the cell behaviour in compression. The method and associated modelling are described, with results mainly from studies on yeast cells. Continuing difficulties in making a priori predictions of cell breakage in processing are identified. In future, compression testing by micromanipulation might also be used in conjunction with other single cell analytical techniques to study mechanisms controlling form, growth and division of cells and their consequential mechanical behaviour. It ought to be possible to relate cell wall mechanics to cell wall composition and structure, and eventually to underlying gene expression, allowing much greater understanding and control of the cell mechanical properties.
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Affiliation(s)
- Colin R Thomas
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK,
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