1
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Abu Quba AA, Goebel MO, Karagulyan M, Miltner A, Kästner M, Bachmann J, Schaumann GE, Diehl D. Hypertonic stress induced changes of Pseudomonas fluorescens adhesion towards soil minerals studied by AFM. Sci Rep 2023; 13:17146. [PMID: 37816775 PMCID: PMC10564757 DOI: 10.1038/s41598-023-44256-7] [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: 01/19/2023] [Accepted: 10/05/2023] [Indexed: 10/12/2023] Open
Abstract
Studying bacterial adhesion to mineral surfaces is crucial for understanding soil properties. Recent research suggests that minimal coverage of sand particles with cell fragments significantly reduces soil wettability. Using atomic force microscopy (AFM), we investigated the influence of hypertonic stress on Pseudomonas fluorescens adhesion to four different minerals in water. These findings were compared with theoretical XDLVO predictions. To make adhesion force measurements comparable for irregularly shaped particles, we normalized adhesion forces by the respective cell-mineral contact area. Our study revealed an inverse relationship between wettability and the surface-organic carbon content of the minerals. This relationship was evident in the increased adhesion of cells to minerals with decreasing wettability. This phenomenon was attributed to hydrophobic interactions, which appeared to be predominant in all cell-mineral interaction scenarios alongside with hydrogen bonding. Moreover, while montmorillonite and goethite exhibited stronger adhesion to stressed cells, presumably due to enhanced hydrophobic interactions, kaolinite showed an unexpected trend of weaker adhesion to stressed cells. Surprisingly, the adhesion of quartz remained independent of cell stress level. Discrepancies between measured cell-mineral interactions and those calculated by XDLVO, assuming an idealized sphere-plane geometry, helped us interpret the chemical heterogeneity arising from differently exposed edges and planes of minerals. Our results suggest that bacteria may have a significant impact on soil wettability under changing moisture condition.
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Affiliation(s)
- Abd Alaziz Abu Quba
- Institute for Environmental Sciences, University of Kaiserslautern-Landau (RPTU), Landau, Germany
| | - Marc-Oliver Goebel
- Institute of Soil Science, Leibniz Universität Hannover, Hannover, Germany
| | - Mariam Karagulyan
- Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Anja Miltner
- Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Matthias Kästner
- Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Jörg Bachmann
- Institute of Soil Science, Leibniz Universität Hannover, Hannover, Germany
| | - Gabriele E Schaumann
- Institute for Environmental Sciences, University of Kaiserslautern-Landau (RPTU), Landau, Germany
| | - Doerte Diehl
- Institute for Environmental Sciences, University of Kaiserslautern-Landau (RPTU), Landau, Germany.
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2
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Caniglia G, Tezcan G, Meloni GN, Unwin PR, Kranz C. Probing and Visualizing Interfacial Charge at Surfaces in Aqueous Solution. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2022; 15:247-267. [PMID: 35259914 DOI: 10.1146/annurev-anchem-121521-122615] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Surface charge density and distribution play an important role in almost all interfacial processes, influencing, for example, adsorption, colloidal stability, functional material activity, electrochemical processes, corrosion, nanoparticle toxicity, and cellular processes such as signaling, absorption, and adhesion. Understanding the heterogeneity in, and distribution of, surface and interfacial charge is key to elucidating the mechanisms underlying reactivity, the stability of materials, and biophysical processes. Atomic force microscopy (AFM) and scanning ion conductance microscopy (SICM) are highly suitable for probing the material/electrolyte interface at the nanoscale through recent advances in probe design, significant instrumental (hardware and software) developments, and the evolution of multifunctional imaging protocols. Here, we assess the capability of AFM and SICM for surface charge mapping, covering the basic underpinning principles alongside experimental considerations. We illustrate and compare the use of AFM and SICM for visualizing surface and interfacial charge with examples from materials science, geochemistry, and the life sciences.
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Affiliation(s)
- Giada Caniglia
- Institute of Analytical and Bioanalytical Chemistry, Ulm University, Ulm, Germany;
| | - Gözde Tezcan
- Department of Chemistry, University of Warwick, Coventry, United Kingdom;
| | - Gabriel N Meloni
- Department of Chemistry, University of Warwick, Coventry, United Kingdom;
| | - Patrick R Unwin
- Department of Chemistry, University of Warwick, Coventry, United Kingdom;
| | - Christine Kranz
- Institute of Analytical and Bioanalytical Chemistry, Ulm University, Ulm, Germany;
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3
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Cremin K, Jones BA, Teahan J, Meloni GN, Perry D, Zerfass C, Asally M, Soyer OS, Unwin PR. Scanning Ion Conductance Microscopy Reveals Differences in the Ionic Environments of Gram-Positive and Negative Bacteria. Anal Chem 2020; 92:16024-16032. [PMID: 33241929 DOI: 10.1021/acs.analchem.0c03653] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
This paper reports on the use of scanning ion conductance microscopy (SICM) to locally map the ionic properties and charge environment of two live bacterial strains: the Gram-negative Escherichia coli and the Gram-positive Bacillus subtilis. SICM results find heterogeneities across the bacterial surface and significant differences among the Gram-positive and Gram-negative bacteria. The bioelectrical environment of the B. subtilis was found to be considerably more negatively charged compared to E. coli. SICM measurements, fitted to a simplified finite element method (FEM) model, revealed surface charge values of -80 to -140 mC m-2 for the Gram-negative E. coli. The Gram-positive B. subtilis show a much higher conductivity around the cell wall, and surface charge values between -350 and -450 mC m-2 were found using the same simplified model. SICM was also able to detect regions of high negative charge near B. subtilis, not detected in the topographical SICM response and attributed to the extracellular polymeric substance. To further explore how the B. subtilis cell wall structure can influence the SICM current response, a more comprehensive FEM model, accounting for the physical properties of the Gram-positive cell wall, was developed. The new model provides a more realistic description of the cell wall and allows investigation of the relation between its key properties and SICM currents, building foundations to further investigate and improve understanding of the Gram-positive cellular microenvironment.
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Affiliation(s)
- Kelsey Cremin
- Bio-Electrical Engineering Innovation Hub, University of Warwick, Coventry CV4 7AL, U.K.,Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K.,Molecular Analytical Science Centre for Doctoral Training (MAS CDT), University of Warwick, Coventry CV4 7AL, U.K.,School of Life Sciences, University of Warwick, Coventry CV4 7AL, U.K
| | - Bryn A Jones
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
| | - James Teahan
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K.,Molecular Analytical Science Centre for Doctoral Training (MAS CDT), University of Warwick, Coventry CV4 7AL, U.K
| | - Gabriel N Meloni
- Bio-Electrical Engineering Innovation Hub, University of Warwick, Coventry CV4 7AL, U.K.,Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
| | - David Perry
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
| | - Christian Zerfass
- Bio-Electrical Engineering Innovation Hub, University of Warwick, Coventry CV4 7AL, U.K.,School of Life Sciences, University of Warwick, Coventry CV4 7AL, U.K
| | - Munehiro Asally
- Bio-Electrical Engineering Innovation Hub, University of Warwick, Coventry CV4 7AL, U.K.,School of Life Sciences, University of Warwick, Coventry CV4 7AL, U.K
| | - Orkun S Soyer
- Bio-Electrical Engineering Innovation Hub, University of Warwick, Coventry CV4 7AL, U.K.,School of Life Sciences, University of Warwick, Coventry CV4 7AL, U.K
| | - Patrick R Unwin
- Bio-Electrical Engineering Innovation Hub, University of Warwick, Coventry CV4 7AL, U.K.,Department of Chemistry, University of Warwick, Coventry CV4 7AL, U.K
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4
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Li L, Steinmetz NF, Eppell SJ, Zypman FR. Charge Calibration Standard for Atomic Force Microscope Tips in Liquids. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:13621-13632. [PMID: 33155810 DOI: 10.1021/acs.langmuir.0c02455] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
An electric charge standard with nanoscale resolution is created using the known charge distribution of a single tobacco mosaic virus coat protein combined with the known packing of these proteins in the virus capsid. This advances the ability to measure charge on nanometric samples. Experimental atomic force microscope (AFM) force-distance curves are collected under aqueous conditions with controlled pH and ion concentration. A mathematical model that considers a polarizable dielectric tip immersed in an electrolyte is used to obtain charge density from the AFM measurements. Interactions between the tip and the sample are modeled using theory that includes monopolar electrostatic interactions, dipolar interactions, screening from both the dielectric nature of ambient water and solvated ions as described by the linear Poisson-Boltzmann equation, and hard-core repulsion. It is found that the tip charge density changes on a timescale of hours requiring recalibration of the tip for experiments lasting more than an hour. As an example of how a charge-calibrated tip may be used, the surface charge densities on 20 individual carboxylate-modified polystyrene (PS) beads are measured. The average of these AFM-measured bead charge densities is compared with the value obtained from conventional titration combined with electron microscopy. The two values are found to agree within 20%. While the comparison demonstrates similarity of the two charge measurements, hypotheses are put forward as to why the two techniques might be expected not to provide identical mean charge densities. The considerations used to build these hypotheses thus underscore the relevance of the method performed here if charge information is required on individual nanoparticles.
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Affiliation(s)
- Li Li
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Nicole F Steinmetz
- Departments of NanoEngineering, Bioengineering, and Radiology, Moores Cancer Center, Center for Nano-ImmunoEngineering, University of California-San Diego, La Jolla, California 92039, United States
| | - Steven J Eppell
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Fredy R Zypman
- Department of Physics, Yeshiva University, Manhattan, New York 10033, United States
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5
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Li L, Eppell SJ, Zypman FR. Method to Quantify Nanoscale Surface Charge in Liquid with Atomic Force Microscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:4123-4134. [PMID: 32208713 DOI: 10.1021/acs.langmuir.9b03602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
A theory is presented to obtain surface charge density on nanoscale objects from data in the snap-to-contact portion of an atomic force microscope force-separation curve. The mathematical model takes into account the tip's dielectric constant using the Self-Consistent Sum of Dipoles theory which includes the charge-charge interaction and the charge-dipole interaction with electrolyte-induced exponentially decaying screening, Debye and London dipolar force, and fluid viscosity including confined fluid layers to account for energy dissipation. Using previously published experimental data, the mathematical model is applied to measure the surface charge density on an individual nanoscale amine-modified polystyrene bead immobilized on the basal plane of highly oriented pyrolytic graphite in buffered aqueous solution. Within the experimental uncertainty, the magnitude of the charge density on a single bead obtained using the new method falls within the distribution of values determined by the manufacturer using titration and electron microscopy.
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Affiliation(s)
- Li Li
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
| | - Steven J Eppell
- Department of Biomedical Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, United States
| | - Fredy R Zypman
- Department of Physics, Yeshiva University, 2495 Amsterdam Avenue, Manhattan, New York 10033, United States
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6
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Laskowski FAL, Oener SZ, Nellist MR, Gordon AM, Bain DC, Fehrs JL, Boettcher SW. Nanoscale semiconductor/catalyst interfaces in photoelectrochemistry. NATURE MATERIALS 2020; 19:69-76. [PMID: 31591528 DOI: 10.1038/s41563-019-0488-z] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 08/18/2019] [Indexed: 05/12/2023]
Abstract
Semiconductor structures (for example, films, wires, particles) used in photoelectrochemical devices are often decorated with nanoparticles that catalyse fuel-forming reactions, including water oxidation, hydrogen evolution or carbon-dioxide reduction. For high performance, the catalyst nanoparticles must form charge-carrier-selective contacts with the underlying light-absorbing semiconductor, facilitating either hole or electron transfer while inhibiting collection of the opposite carrier. Despite the key role played by such selective contacts in photoelectrochemical energy conversion and storage, the underlying nanoscale interfaces are poorly understood because direct measurement of their properties is challenging, especially under operating conditions. Using an n-Si/Ni photoanode model system and potential-sensing atomic force microscopy, we measure interfacial electron-transfer processes and map the photovoltage generated during photoelectrochemical oxygen evolution at nanoscopic semiconductor/catalyst interfaces. We discover interfaces where the selectivity of low-Schottky-barrier n-Si/Ni contacts for holes is enhanced via a nanoscale size-dependent pinch-off effect produced when surrounding high-barrier regions develop during device operation. These results thus demonstrate (1) the ability to make nanoscale operando measurements of contact properties under practical photoelectrochemical conditions and (2) a design principle to control the flow of electrons and holes across semiconductor/catalyst junctions that is broadly relevant to different photoelectrochemical devices.
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Affiliation(s)
| | - Sebastian Z Oener
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR, USA
| | - Michael R Nellist
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR, USA
| | - Adrian M Gordon
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR, USA
| | - David C Bain
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR, USA
| | - Jessica L Fehrs
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR, USA
| | - Shannon W Boettcher
- Department of Chemistry and Biochemistry, University of Oregon, Eugene, OR, USA.
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7
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Wang Y, Han X, Cui Z, Shi D. Bioelectricity, Its Fundamentals, Characterization Methodology, and Applications in Nano-Bioprobing and Cancer Diagnosis. ACTA ACUST UNITED AC 2019; 3:e1900101. [PMID: 32648718 DOI: 10.1002/adbi.201900101] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 08/01/2019] [Indexed: 12/11/2022]
Abstract
Bioelectricity is an essential characteristic of a biological system that has played an important role in medical diagnosis particularly in cancer liquid biopsy. However, its biophysical origin and measurements have presented great challenges in experimental methodologies. For instance, in dynamic cell processes, bioelectricity cannot be accurately determined as a static electrical potential via electrophoresis. Cancer cells fundamentally differ from normal cells by having a much higher rate of glycolysis resulting in net negative charges on cell surfaces. The most recent investigations on cancer cell surface charge that is the direct bio-electrical manifestation of the "Warburg Effect," which can be directly monitored by specially designed nanoprobes, has been provided. The most up-to-date research results from charge-mediated cell targeting are reviewed. Correlations between the cell surface charge and cancer cell metabolism are established based on cell/probe electrostatic interactions. Bioelectricity is utilized not only as an analyte for investigation of the metabolic state of the cancer cells, but also applied in electrostatically and magnetically capturing of the circulating tumor cells from whole blood. Also reviewed is on the isolation of Candida albicans via bioelectricity-driven nanoparticle binding on fungus with surface charges.
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Affiliation(s)
- Yilong Wang
- The Institute for Translational Nanomedicine, Shanghai East Hospital, The Institute for Biomedical Engineering & Nano Science, Tongji University School of Medicine, Shanghai, 200092, P. R. China
| | - Xiao Han
- The Institute for Translational Nanomedicine, Shanghai East Hospital, The Institute for Biomedical Engineering & Nano Science, Tongji University School of Medicine, Shanghai, 200092, P. R. China
| | - Zheng Cui
- The Institute for Translational Nanomedicine, Shanghai East Hospital, The Institute for Biomedical Engineering & Nano Science, Tongji University School of Medicine, Shanghai, 200092, P. R. China.,Department of Pathology, Wake Forest University School of Medicine, Winston-Salem, NC, 27157, USA
| | - Donglu Shi
- Materials Science and Engineering Program, Department of Mechanical and Materials Engineering, College of Engineering and Applied Science, University of Cincinnati, Cincinnati, OH, 45221, USA
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8
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Golan M, Pribyl J, Pesl M, Jelinkova S, Acimovic I, Jaros J, Rotrekl V, Falk M, Sefc L, Skladal P, Kratochvilova I. Cryopreserved Cells Regeneration Monitored by Atomic Force Microscopy and Correlated With State of Cytoskeleton and Nuclear Membrane. IEEE Trans Nanobioscience 2018; 17:485-497. [PMID: 30307873 DOI: 10.1109/tnb.2018.2873425] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Atomic force microscopy (AFM) helps to describe and explain the mechanobiological properties of living cells on the nanoscale level under physiological conditions. The stiffness of cells is an important parameter reflecting cell physiology. Here, we have provided the first study of the stiffness of cryopreserved cells during post-thawing regeneration using AFM combined with confocal fluorescence microscopy. We demonstrated that the nonfrozen cell stiffness decreased proportionally to the cryoprotectant concentration in the medium. AFM allowed us to map cell surface reconstitution in real time after a freeze/thaw cycle and to monitor the regeneration processes at different depths of the cell and even different parts of the cell surface (nucleus and edge). Fluorescence microscopy showed that the cytoskeleton in fibroblasts, though damaged by the freeze/thaw cycle, is reconstructed after long-term plating. Confocal microscopy confirmed that structural changes affect the nuclear envelopes in cryopreserved cells. AFM nanoindentation analysis could be used as a noninvasive method to identify cells that have regenerated their surface mechanical properties with the proper dynamics and to a sufficient degree. This identification can be important particularly in the field of in vitro fertilization and in future cell-based regeneration strategies.
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9
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Sacha GM, Verdaguer A, Salmeron M. A Model for the Characterization of the Polarizability of Thin Films Independently of the Thickness of the Film. J Phys Chem B 2018; 122:904-909. [PMID: 29087709 DOI: 10.1021/acs.jpcb.7b06975] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The dielectric properties of thin films can be modified relative to the bulk material because the interaction between film and substrate influences the mobility of the atoms or molecules in the first layers. Here we show that a strong scale effect occurs in nanometer size octadecylammine thin films. This effect is attributed to the different distribution of molecules depending on the size of the film. To accurately describe this effect, we have developed a model which is a reinterpretation of the linearized Thomas-Fermi approximation. Within this model, we have been able to characterize the polarizability of thin films independently of the thickness of the film.
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Affiliation(s)
- G M Sacha
- Universidad Autónoma de Madrid , Campus de Cantoblanco, 28049 Madrid, Spain
| | - A Verdaguer
- Institut de Ciència de Materials de Barcelona ICMAB-CSIC , Campus de la UAB, 08193 Bellaterra, Spain
| | - M Salmeron
- Materials Science Division, Lawrence Berkeley National Laboratory , 94720 Berkeley, California, United States
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10
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Spengler C, Thewes N, Jung P, Bischoff M, Jacobs K. Determination of the nano-scaled contact area of staphylococcal cells. NANOSCALE 2017; 9:10084-10093. [PMID: 28695218 DOI: 10.1039/c7nr02297b] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Bacterial adhesion is a crucial step during the development of infections as well as the formation of biofilms. Hence, fundamental research of bacterial adhesion mechanisms is of utmost importance. So far, less is known about the size of the contact area between bacterial cells and a surface. This gap will be filled by this study using a single-cell force spectroscopy-based method to investigate the contact area between a single bacterial cell of Staphylococcus aureus and a solid substrate. The technique relies on the strong influence of the hydrophobic interaction on bacterial adhesion: by incrementally crossing a very sharp hydrophobic/hydrophilic interface while performing force-distance curves with a single bacterial probe, the bacterial contact area can be determined. Assuming circular contact areas, their radii - determined in our experiments - are in the range from tens of nanometers to a few hundred nanometers. The contact area can be slightly enlarged by a larger load force, yet does not resemble a Hertzian contact, rather, the enlargement is a property of the individual bacterial cell. Additionally, Staphylococcus carnosus has been probed, which is less adherent than S. aureus, yet both bacteria exhibit a similar contact area size. This corroborates the notion that the adhesive strength of bacteria is not a matter of contact area, but rather a matter of which and how many molecules of the bacterial species' cell wall form the contact. Moreover, our method of determining the contact area can be applied to other microorganisms and the results might also be useful for studies using nanoparticles covered with soft, macromolecular coatings.
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Affiliation(s)
- Christian Spengler
- Department of Experimental Physics, Saarland University, 66041 Saarbrücken, Germany.
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11
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McDonough RT, Zheng H, Alila MA, Goodisman J, Chaiken J. Optical interference probe of biofilm hydrology: label-free characterization of the dynamic hydration behavior of native biofilms. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:35003. [PMID: 28271122 DOI: 10.1117/1.jbo.22.3.035003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 02/10/2017] [Indexed: 06/06/2023]
Abstract
Biofilm produced by Escherichia coli (E. coli) or Pseudomonas aeruginosa (P. aeruginosa) on quartz or polystyrene is removed from the culture medium and drained. Observed optical interference fringes indicate the presence of a layer of uniform thickness with refractive index different from air-dried biofilm. Fringe wavelengths indicate that layer optical thickness is < 20 ?? ? m or 1 to 2 orders of magnitude thinner than the biofilm as measured by confocal Raman microscopy or fluorescence imaging of the bacteria. Raman shows that films have an alginate-like carbohydrate composition. Fringe amplitudes indicate that the refractive index of the interfering layer is higher than dry alginate. Drying and rehydration nondestructively thins and restores the interfering layer. The strength of the 1451-nm near infrared water absorption varies in unison with thickness. Absorption and layer thickness are proportional for films with different bacteria, substrates, and growth conditions. Formation of the interfering layer is general, possibly depending more on the chemical nature of alginate-like materials than bacterial processes. Films grown during the exponential growth phase produce no observable interference fringes, indicating requirements for layer formation are not met, possibly reflecting bacterial activities at that stage. The interfering layer might provide a protective environment for bacteria when water is scarce.
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Affiliation(s)
| | - Hewen Zheng
- Syracuse University, Department of Chemistry, Syracuse, New York
| | - Mercy A Alila
- Syracuse University, Department of Chemistry, Syracuse, New York
| | - Jerry Goodisman
- Syracuse University, Department of Chemistry, Syracuse, New York
| | - Joseph Chaiken
- Syracuse University, Department of Chemistry, Syracuse, New York
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12
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Chan AJ, Sarkar P, Gaboriaud F, Fontaine-Aupart MP, Marlière C. Control of interface interactions between natural rubber and solid surfaces through charge effects: an AFM study in force spectroscopic mode. RSC Adv 2017. [DOI: 10.1039/c7ra08589c] [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] Open
Abstract
Adhesion of nanoparticles (natural rubber) is monitored by slight changes in the surface charge state of the contacting solid surfaces.
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Affiliation(s)
- Alan Jenkin Chan
- Institut des Sciences Moléculaires d'Orsay, ISMO
- Université Paris-Sud
- CNRS
- 91405 Orsay Cedex
- France
| | | | - Fabien Gaboriaud
- Manufacture Française des Pneumatiques Michelin
- F-63040 Clermont Ferrand 9
- France
| | | | - Christian Marlière
- Institut des Sciences Moléculaires d'Orsay, ISMO
- Université Paris-Sud
- CNRS
- 91405 Orsay Cedex
- France
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13
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Bao H, Yang B, Zhang X, Lei L, Li Z. Bacteria-templated fabrication of a charge heterogeneous polymeric interface for highly specific bacterial recognition. Chem Commun (Camb) 2017; 53:2319-2322. [DOI: 10.1039/c6cc09242j] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Using bacteria-templated polymerization, a novel bacteria-imprinted polymer (BIP) was fabricated for bacterial recognition.
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Affiliation(s)
- Han Bao
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education
- Zhejiang University
- Hangzhou 310027
- P. R. China
- College of Chemical and Biological Engineering
| | - Bin Yang
- College of Chemical and Biological Engineering
- Zhejiang University
- Hangzhou 310027
- P. R. China
| | - Xingwang Zhang
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education
- Zhejiang University
- Hangzhou 310027
- P. R. China
- College of Chemical and Biological Engineering
| | - Lecheng Lei
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education
- Zhejiang University
- Hangzhou 310027
- P. R. China
- College of Chemical and Biological Engineering
| | - Zhongjian Li
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education
- Zhejiang University
- Hangzhou 310027
- P. R. China
- College of Chemical and Biological Engineering
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14
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Rauch C, Cherkaoui M, Egan S, Leigh J. The bio-physics of condensation of divalent cations into the bacterial wall has implications for growth of Gram-positive bacteria. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1859:282-288. [PMID: 27940173 DOI: 10.1016/j.bbamem.2016.12.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 11/30/2016] [Accepted: 12/06/2016] [Indexed: 10/20/2022]
Abstract
BACKGROUND The anionic-polyelectrolyte nature of the wall of Gram-positive bacteria has long been suspected to be involved in homeostasis of essential cations and bacterial growth. A better understanding of the coupling between the biophysics and the biology of the wall is essential to understand some key features at play in ion-homeostasis in this living system. METHODS We consider the wall as a polyelectrolyte gel and balance the long-range electrostatic repulsion within this structure against the penalty entropy required to condense cations around wall polyelectrolytes. The resulting equations define how cations interact physically with the wall and the characteristic time required for a cation to leave the wall and enter into the bacterium to enable its usage for bacterial metabolism and growth. RESULTS The model was challenged against experimental data regarding growth of Gram-positive bacteria in the presence of varying concentration of divalent ions. The model explains qualitatively and quantitatively how divalent cations interact with the wall as well as how the biophysical properties of the wall impact on bacterial growth (in particular the initiation of bacterial growth). CONCLUSION The interplay between polymer biophysics and the biology of Gram positive bacteria is defined for the first time as a new set of variables that contribute to the kinetics of bacterial growth. GENERAL SIGNIFICANCE Providing an understanding of how bacteria capture essential metal cations in way that does not follow usual binding laws has implications when considering the control of such organisms and their ability to survive and grow in extreme environments.
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Affiliation(s)
- Cyril Rauch
- School of Veterinary Medicine and Science, University of Nottingham, College Road, Sutton Bonington, LE12 5RD, UK.
| | - Mohammed Cherkaoui
- School of Veterinary Medicine and Science, University of Nottingham, College Road, Sutton Bonington, LE12 5RD, UK
| | - Sharon Egan
- School of Veterinary Medicine and Science, University of Nottingham, College Road, Sutton Bonington, LE12 5RD, UK
| | - James Leigh
- School of Veterinary Medicine and Science, University of Nottingham, College Road, Sutton Bonington, LE12 5RD, UK
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Cell wall as a target for bacteria inactivation by pulsed electric fields. Sci Rep 2016; 6:19778. [PMID: 26830154 PMCID: PMC4735277 DOI: 10.1038/srep19778] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 12/07/2015] [Indexed: 12/23/2022] Open
Abstract
The integrity and morphology of bacteria is sustained by the cell wall, the target of the main microbial inactivation processes. One promising approach to inactivation is based on the use of pulsed electric fields (PEF). The current dogma is that irreversible cell membrane electro-permeabilisation causes the death of the bacteria. However, the actual effect on the cell-wall architecture has been poorly explored. Here we combine atomic force microscopy and electron microscopy to study the cell-wall organization of living Bacillus pumilus bacteria at the nanoscale. For vegetative bacteria, exposure to PEF led to structural disorganization correlated with morphological and mechanical alterations of the cell wall. For spores, PEF exposure led to the partial destruction of coat protein nanostructures, associated with internal alterations of cortex and core. Our findings reveal for the first time that the cell wall and coat architecture are directly involved in the electro-eradication of bacteria.
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