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Kurjahn M, Deka A, Girot A, Abbaspour L, Klumpp S, Lorenz M, Bäumchen O, Karpitschka S. Quantifying gliding forces of filamentous cyanobacteria by self-buckling. eLife 2024; 12:RP87450. [PMID: 38864737 PMCID: PMC11178357 DOI: 10.7554/elife.87450] [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] [Indexed: 06/13/2024] Open
Abstract
Filamentous cyanobacteria are one of the oldest and today still most abundant lifeforms on earth, with manifold implications in ecology and economics. Their flexible filaments, often several hundred cells long, exhibit gliding motility in contact with solid surfaces. The underlying force generating mechanism is not yet understood. Here, we demonstrate that propulsion forces and friction coefficients are strongly coupled in the gliding motility of filamentous cyanobacteria. We directly measure their bending moduli using micropipette force sensors, and quantify propulsion and friction forces by analyzing their self-buckling behavior, complemented with analytical theory and simulations. The results indicate that slime extrusion unlikely generates the gliding forces, but support adhesion-based hypotheses, similar to the better-studied single-celled myxobacteria. The critical self-buckling lengths align well with the peaks of natural length distributions, indicating the importance of self-buckling for the organization of their collective in natural and artificial settings.
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Affiliation(s)
- Maximilian Kurjahn
- Max Planck Institute for Dynamics and Self-Organization (MPI-DS)GöttingenGermany
| | - Antaran Deka
- Max Planck Institute for Dynamics and Self-Organization (MPI-DS)GöttingenGermany
| | - Antoine Girot
- Max Planck Institute for Dynamics and Self-Organization (MPI-DS)GöttingenGermany
- Experimental Physics V, University of BayreuthBayreuthGermany
| | - Leila Abbaspour
- Max Planck School Matter to Life, University of GöttingenGöttingenGermany
- Institute for Dynamics of Complex Systems, University of GöttingenGöttingenGermany
| | - Stefan Klumpp
- Max Planck School Matter to Life, University of GöttingenGöttingenGermany
- Institute for Dynamics of Complex Systems, University of GöttingenGöttingenGermany
| | - Maike Lorenz
- Department of Experimental Phycology and SAG Culture Collection of Algae Albrecht-von-Haller Institute for Plant Science, University of GöttingenGöttingenGermany
| | - Oliver Bäumchen
- Max Planck Institute for Dynamics and Self-Organization (MPI-DS)GöttingenGermany
- Experimental Physics V, University of BayreuthBayreuthGermany
| | - Stefan Karpitschka
- Max Planck Institute for Dynamics and Self-Organization (MPI-DS)GöttingenGermany
- Fachbereich Physik, University of KonstanzKonstanzGermany
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2
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Faluweki MK, Cammann J, Mazza MG, Goehring L. Active Spaghetti: Collective Organization in Cyanobacteria. PHYSICAL REVIEW LETTERS 2023; 131:158303. [PMID: 37897773 DOI: 10.1103/physrevlett.131.158303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 08/30/2023] [Indexed: 10/30/2023]
Abstract
Filamentous cyanobacteria can show fascinating examples of nonequilibrium self-organization, which, however, are not well understood from a physical perspective. We investigate the motility and collective organization of colonies of these simple multicellular lifeforms. As their area density increases, linear chains of cells gliding on a substrate show a transition from an isotropic distribution to bundles of filaments arranged in a reticulate pattern. Based on our experimental observations of individual behavior and pairwise interactions, we introduce a nonreciprocal model accounting for the filaments' large aspect ratio, fluctuations in curvature, motility, and nematic interactions. This minimal model of active filaments recapitulates the observations, and rationalizes the appearance of a characteristic length scale in the system, based on the Péclet number of the cyanobacteria filaments.
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Affiliation(s)
- Mixon K Faluweki
- School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, United Kingdom
- Malawi Institute of Technology, Malawi University of Science and Technology, S150 Road, Thyolo 310105, Malawi
| | - Jan Cammann
- Interdisciplinary Centre for Mathematical Modelling and Department of Mathematical Sciences, Loughborough University, Loughborough, Leicestershire LE11 3TU, United Kingdom
| | - Marco G Mazza
- Interdisciplinary Centre for Mathematical Modelling and Department of Mathematical Sciences, Loughborough University, Loughborough, Leicestershire LE11 3TU, United Kingdom
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), Am Faßberg 17, 37077 Göttingen, Germany
| | - Lucas Goehring
- School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, United Kingdom
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3
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Faluweki MK, Goehring L. Structural mechanics of filamentous cyanobacteria. J R Soc Interface 2022; 19:20220268. [PMID: 35892203 PMCID: PMC9326267 DOI: 10.1098/rsif.2022.0268] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 07/05/2022] [Indexed: 06/15/2023] Open
Abstract
Filamentous cyanobacteria, forming long strands of connected cells, are one of the earliest and most successful forms of life on Earth. They exhibit self-organized behaviour, forming large-scale patterns in structures like biomats and stromatolites. The mechanical properties of these rigid structures have contributed to their biological success and are important to applications like algae-based biofuel production. For active polymers like these cyanobacteria, one of the most important mechanical properties is the bending modulus, or flexural rigidity. Here, we quantify the bending stiffness of three species of filamentous cyanobacteria, of order Oscillatoriales, using a microfluidic flow device where single filaments are deflected by fluid flow. This is complemented by measurements of Young's modulus of the cell wall, via nanoindentation, and the cell wall thickness. We find that the stiffness of the cyanobacteria is well-captured by a simple model of a flexible rod, with most stress carried by a rigid outer wall. Finally, we connect these results to the curved shapes that these cyanobacteria naturally take while gliding, and quantify the forces generated internally to maintain this shape. The measurements can be used to model interactions between cyanobacteria, or with their environment, and how their collective behaviour emerges from such interactions.
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Affiliation(s)
- Mixon K. Faluweki
- School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, UK
- Malawi Institute of Technology, Malawi University of Science and Technology, Limbe, Malawi
| | - Lucas Goehring
- School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, UK
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4
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Lamparter T, Babian J, Fröhlich K, Mielke M, Weber N, Wunsch N, Zais F, Schulz K, Aschmann V, Spohrer N, Krauß N. The involvement of type IV pili and the phytochrome CphA in gliding motility, lateral motility and photophobotaxis of the cyanobacterium Phormidium lacuna. PLoS One 2022; 17:e0249509. [PMID: 35085243 PMCID: PMC8794177 DOI: 10.1371/journal.pone.0249509] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 12/25/2021] [Indexed: 11/29/2022] Open
Abstract
Phormidium lacuna is a naturally competent, filamentous cyanobacterium that belongs to the order Oscillatoriales. The filaments are motile on agar and other surfaces and display rapid lateral movements in liquid culture. Furthermore, they exhibit a photophobotactic response, a phototactic response towards light that is projected vertically onto the area covered by the culture. However, the molecular mechanisms underlying these phenomena are unclear. We performed the first molecular studies on the motility of an Oscillatoriales member. We generated mutants in which a kanamycin resistance cassette (KanR) was integrated in the phytochrome gene cphA and in various genes of the type IV pilin apparatus. pilM, pilN, pilQ and pilT mutants were defective in gliding motility, lateral movements and photophobotaxis, indicating that type IV pili are involved in all three kinds of motility. pilB mutants were only partially blocked in terms of their responses. pilB is the proposed ATPase for expelling of the filament in type IV pili. The genome reveals proteins sharing weak pilB homology in the ATPase region, these might explain the incomplete phenotype. The cphA mutant revealed a significantly reduced photophobotactic response towards red light. Therefore, our results imply that CphA acts as one of several photophobotaxis photoreceptors or that it could modulate the photophobotaxis response.
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Affiliation(s)
- Tilman Lamparter
- Karlsruhe Institute of Technology KIT, Botanical Institute, Karlsruhe, Germany
- * E-mail:
| | - Jennifer Babian
- Karlsruhe Institute of Technology KIT, Botanical Institute, Karlsruhe, Germany
| | - Katrin Fröhlich
- Karlsruhe Institute of Technology KIT, Botanical Institute, Karlsruhe, Germany
| | - Marion Mielke
- Karlsruhe Institute of Technology KIT, Botanical Institute, Karlsruhe, Germany
| | - Nora Weber
- Karlsruhe Institute of Technology KIT, Botanical Institute, Karlsruhe, Germany
| | - Nadja Wunsch
- Karlsruhe Institute of Technology KIT, Botanical Institute, Karlsruhe, Germany
| | - Finn Zais
- Karlsruhe Institute of Technology KIT, Botanical Institute, Karlsruhe, Germany
| | - Kevin Schulz
- Karlsruhe Institute of Technology KIT, Botanical Institute, Karlsruhe, Germany
| | - Vera Aschmann
- Karlsruhe Institute of Technology KIT, Botanical Institute, Karlsruhe, Germany
| | - Nina Spohrer
- Karlsruhe Institute of Technology KIT, Botanical Institute, Karlsruhe, Germany
| | - Norbert Krauß
- Karlsruhe Institute of Technology KIT, Botanical Institute, Karlsruhe, Germany
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5
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Evans CT, Baldock SJ, Hardy JG, Payton O, Picco L, Allen MJ. A Non-Destructive, Tuneable Method to Isolate Live Cells for High-Speed AFM Analysis. Microorganisms 2021; 9:microorganisms9040680. [PMID: 33806176 PMCID: PMC8066395 DOI: 10.3390/microorganisms9040680] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 03/19/2021] [Accepted: 03/22/2021] [Indexed: 11/24/2022] Open
Abstract
Suitable immobilisation of microorganisms and single cells is key for high-resolution topographical imaging and study of mechanical properties with atomic force microscopy (AFM) under physiologically relevant conditions. Sample preparation techniques must be able to withstand the forces exerted by the Z range-limited cantilever tip, and not negatively affect the sample surface for data acquisition. Here, we describe an inherently flexible methodology, utilising the high-resolution three-dimensional based printing technique of multiphoton polymerisation to rapidly generate bespoke arrays for cellular AFM analysis. As an example, we present data collected from live Emiliania huxleyi cells, unicellular microalgae, imaged by contact mode High-Speed Atomic Force Microscopy (HS-AFM), including one cell that was imaged continuously for over 90 min.
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Affiliation(s)
- Christopher T. Evans
- Plymouth Marine Laboratory, Plymouth PL1 3DH, UK;
- Interface Analysis Centre, Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL, UK;
| | - Sara J. Baldock
- Department of Chemistry, Lancaster University, Lancaster LA1 4YB, UK; (S.J.B.); (J.G.H.)
| | - John G. Hardy
- Department of Chemistry, Lancaster University, Lancaster LA1 4YB, UK; (S.J.B.); (J.G.H.)
- Materials Science Institute, Lancaster University, Lancaster LA1 4YB, UK
| | - Oliver Payton
- Interface Analysis Centre, Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL, UK;
| | - Loren Picco
- Department of Physics, Virginia Commonwealth University, Richmond, VA 23284, USA;
| | - Michael J. Allen
- Plymouth Marine Laboratory, Plymouth PL1 3DH, UK;
- Department of Biosciences, College of Life and Environmental Sciences, University of Exeter, Stocker Road EX4 4QD, UK
- Correspondence: ; Tel.: +44-(0)-1752-633100
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6
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Wilde A, Mullineaux CW. Light-controlled motility in prokaryotes and the problem of directional light perception. FEMS Microbiol Rev 2017; 41:900-922. [PMID: 29077840 PMCID: PMC5812497 DOI: 10.1093/femsre/fux045] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 09/12/2017] [Indexed: 12/02/2022] Open
Abstract
The natural light environment is important to many prokaryotes. Most obviously, phototrophic prokaryotes need to acclimate their photosynthetic apparatus to the prevailing light conditions, and such acclimation is frequently complemented by motility to enable cells to relocate in search of more favorable illumination conditions. Non-phototrophic prokaryotes may also seek to avoid light at damaging intensities and wavelengths, and many prokaryotes with diverse lifestyles could potentially exploit light signals as a rich source of information about their surroundings and a cue for acclimation and behavior. Here we discuss our current understanding of the ways in which bacteria can perceive the intensity, wavelength and direction of illumination, and the signal transduction networks that link light perception to the control of motile behavior. We discuss the problems of light perception at the prokaryotic scale, and the challenge of directional light perception in small bacterial cells. We explain the peculiarities and the common features of light-controlled motility systems in prokaryotes as diverse as cyanobacteria, purple photosynthetic bacteria, chemoheterotrophic bacteria and haloarchaea.
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Affiliation(s)
- Annegret Wilde
- Institute of Biology III, University of Freiburg, 79104 Freiburg, Germany
- BIOSS Centre of Biological Signalling Studies, University of Freiburg, 79106 Freiburg, Germany
| | - Conrad W. Mullineaux
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
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7
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Interaction of gliding motion of bacteria with rheological properties of the slime. Math Biosci 2017; 290:31-40. [DOI: 10.1016/j.mbs.2017.05.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 05/20/2017] [Accepted: 05/23/2017] [Indexed: 11/20/2022]
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8
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Khayatan B, Meeks JC, Risser DD. Evidence that a modified type IV pilus-like system powers gliding motility and polysaccharide secretion in filamentous cyanobacteria. Mol Microbiol 2015; 98:1021-36. [PMID: 26331359 DOI: 10.1111/mmi.13205] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/03/2015] [Indexed: 01/20/2023]
Abstract
In filamentous cyanobacteria, the mechanism of gliding motility is undefined but posited to be driven by a polysaccharide secretion system known as the junctional pore complex (JPC). Recent evidence implies that the JPC is a modified type IV pilus-like structure encoded for in part by genes in the hps locus. To test this hypothesis, we conducted genetic, cytological and comparative genomics studies on hps and pil genes in Nostoc punctiforme, a species in which motility is restricted to transiently differentiated filaments called hormogonia. Inactivation of most hps and pil genes abolished motility and abolished or drastically reduced secretion of hormogonium polysaccharide, and the subcellular localization of several Pil proteins in motile hormogonia corresponds to the site of the junctional pore complex. The non-motile ΔhpsE-G strain, which lacks three glycosyltransferases that synthesize hormogonium polysaccharide, could be complemented to motility by the addition of medium conditioned by wild-type hormogonia. Based on this result, we speculate that secretion of hormogonium polysaccharide facilitates but does not provide the motive force for gliding. Both the Hps and Pil homologs characterized in this study are almost universally conserved among filamentous cyanobacteria, with the Hps homologs rarely found in unicellular strains. These results support the theory that Hps and Pil proteins compose the JPC, a type IV pilus-like nanomotor that drives motility and polysaccharide secretion in filamentous cyanobacteria.
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Affiliation(s)
- Behzad Khayatan
- Department of Biology, University of the Pacific, Stockton, CA, 95211, USA
| | - John C Meeks
- Department of Microbiology, University of California, Davis, CA, 95616, USA
| | - Douglas D Risser
- Department of Biology, University of the Pacific, Stockton, CA, 95211, USA
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9
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Schuergers N, Wilde A. Appendages of the cyanobacterial cell. Life (Basel) 2015; 5:700-15. [PMID: 25749611 PMCID: PMC4390875 DOI: 10.3390/life5010700] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2015] [Revised: 02/12/2015] [Accepted: 02/25/2015] [Indexed: 12/29/2022] Open
Abstract
Extracellular non-flagellar appendages, called pili or fimbriae, are widespread in gram-negative bacteria. They are involved in many different functions, including motility, adhesion, biofilm formation, and uptake of DNA. Sequencing data for a large number of cyanobacterial genomes revealed that most of them contain genes for pili synthesis. However, only for a very few cyanobacteria structure and function of these appendages have been analyzed. Here, we review the structure and function of type IV pili in Synechocystis sp. PCC 6803 and analyze the distribution of type IV pili associated genes in other cyanobacteria. Further, we discuss the role of the RNA-chaperone Hfq in pilus function and the presence of genes for the chaperone-usher pathway of pilus assembly in cyanobacteria.
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Affiliation(s)
- Nils Schuergers
- University of Freiburg, Institute of Biology III, Schänzlestr. 1, 79104 Freiburg, Germany.
| | - Annegret Wilde
- University of Freiburg, Institute of Biology III, Schänzlestr. 1, 79104 Freiburg, Germany.
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10
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Fiałkowska E, Pajdak-Stós A. Chemical and mechanical signals in inducingPhormidium(Cyanobacteria) defence against their grazers. FEMS Microbiol Ecol 2014; 89:659-69. [DOI: 10.1111/1574-6941.12367] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 05/30/2014] [Accepted: 06/05/2014] [Indexed: 11/29/2022] Open
Affiliation(s)
- Edyta Fiałkowska
- Institute of Environmental Sciences; Jagiellonian University; Kraków Poland
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11
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Vilhauer L, Jervis J, Ray WK, Helm RF. The exo-proteome and exo-metabolome of Nostoc punctiforme (Cyanobacteria) in the presence and absence of nitrate. Arch Microbiol 2014; 196:357-67. [PMID: 24643449 DOI: 10.1007/s00203-014-0974-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 02/27/2014] [Indexed: 01/04/2023]
Abstract
The ability of nitrogen-fixing filamentous Cyanobacteria to adapt to multiple environments comes in part from assessing and responding to external stimuli, an event that is initiated in the extracellular milieu. While it is known that these organisms produce numerous extracellular substances, little work has been done to characterize both the metabolites and proteins present under standard laboratory growth conditions. We have assessed the extracellular milieu of Nostoc punctiforme when grown in liquid culture in the presence and absence of a nitrogen source (nitrate). The extracellular proteins identified were enriched in integrin β-propellor domains and calcium-binding sites with sequences unique to N. punctiforme, supporting a role for extracellular proteins in modulating species-specific recognition and behavior processes. Extracellular proteases are present and active under both conditions, with the cells grown with nitrate having a higher activity when normalized to chlorophyll levels. The released metabolites are enriched in peptidoglycan-derived tetrasaccharides, with higher levels in nitrate-free media.
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Affiliation(s)
- Laura Vilhauer
- Department of Biochemistry, Virginia Tech, 143 Life Sciences 1, Blacksburg, VA, 24061-0910, USA
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12
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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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13
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Chang KC, Chiang YW, Yang CH, Liou JW. Atomic force microscopy in biology and biomedicine. Tzu Chi Med J 2012. [DOI: 10.1016/j.tcmj.2012.08.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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14
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Abstract
Calcium waves are propagated in five main speed ranges which cover a billion-fold range of speeds. We define the fast speed range as 3-30μm/s after correction to a standard temperature of 20°C. Only waves which are not fertilization waves are considered here. 181 such cases are listed here. These are through organisms in all major taxa from cyanobacteria through mammals including human beings except for those through other bacteria, higher plants and fungi. Nearly two-thirds of these speeds lie between 12 and 24μm/s. We argue that their common mechanism in eukaryotes is a reaction-diffusion one involving calcium-induced calcium release, in which calcium waves are propagated along the endoplasmic reticulum. We propose that the gliding movements of some cyanobacteria are driven by fast calcium waves which are propagated along their plasma membranes. Fast calcium waves may drive materials to one end of developing embryos by cellular peristalsis, help coordinate complex cell movements during development and underlie brain injury waves. Moreover, we continue to argue that such waves greatly increase the likelihood that chronic injuries will initiate tumors and cancers before genetic damage occurs. Finally we propose numerous further studies.
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15
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Koiller J, Ehlers KM, Chalub F. Acoustic Streaming, The “Small Invention” of Cianobacteria? ACTA ACUST UNITED AC 2011. [DOI: 10.3989/arbor.2010.746n1256] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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16
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TURNER R, THOMSON N, KIRKHAM J, DEVINE D. Improvement of the pore trapping method to immobilize vital coccoid bacteria for high-resolution AFM: a study ofStaphylococcus aureus. J Microsc 2010; 238:102-10. [DOI: 10.1111/j.1365-2818.2009.03333.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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17
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Fujisawa T, Narikawa R, Okamoto S, Ehira S, Yoshimura H, Suzuki I, Masuda T, Mochimaru M, Takaichi S, Awai K, Sekine M, Horikawa H, Yashiro I, Omata S, Takarada H, Katano Y, Kosugi H, Tanikawa S, Ohmori K, Sato N, Ikeuchi M, Fujita N, Ohmori M. Genomic structure of an economically important cyanobacterium, Arthrospira (Spirulina) platensis NIES-39. DNA Res 2010; 17:85-103. [PMID: 20203057 PMCID: PMC2853384 DOI: 10.1093/dnares/dsq004] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
A filamentous non-N2-fixing cyanobacterium, Arthrospira (Spirulina) platensis, is an important organism for industrial applications and as a food supply. Almost the complete genome of A. platensis NIES-39 was determined in this study. The genome structure of A. platensis is estimated to be a single, circular chromosome of 6.8 Mb, based on optical mapping. Annotation of this 6.7 Mb sequence yielded 6630 protein-coding genes as well as two sets of rRNA genes and 40 tRNA genes. Of the protein-coding genes, 78% are similar to those of other organisms; the remaining 22% are currently unknown. A total 612 kb of the genome comprise group II introns, insertion sequences and some repetitive elements. Group I introns are located in a protein-coding region. Abundant restriction-modification systems were determined. Unique features in the gene composition were noted, particularly in a large number of genes for adenylate cyclase and haemolysin-like Ca2+-binding proteins and in chemotaxis proteins. Filament-specific genes were highlighted by comparative genomic analysis.
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Affiliation(s)
- Takatomo Fujisawa
- Bioresource Information Center, Department of Biotechnology, National Institute of Technology and Evaluation, 2-10-49 Nishihara, Shibuya-ku, Tokyo 151-0066, Japan
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18
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Kurk T, Adams DG, Connell SD, Thomson NH. Three-channel false colour AFM images for improved interpretation of complex surfaces: a study of filamentous cyanobacteria. Ultramicroscopy 2010; 110:718-22. [PMID: 20303215 DOI: 10.1016/j.ultramic.2010.02.038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Imaging signals derived from the atomic force microscope (AFM) are typically presented as separate adjacent images with greyscale or pseudo-colour palettes. We propose that information-rich false-colour composites are a useful means of presenting three-channel AFM image data. This method can aid the interpretation of complex surfaces and facilitate the perception of information that is convoluted across data channels. We illustrate this approach with images of filamentous cyanobacteria imaged in air and under aqueous buffer, using both deflection-modulation (contact) mode and amplitude-modulation (tapping) mode. Topography-dependent contrast in the error and tertiary signals aids the interpretation of the topography signal by contributing additional data, resulting in a more detailed image, and by showing variations in the probe-surface interaction. Moreover, topography-independent contrast and topography-dependent contrast in the tertiary data image (phase or friction) can be distinguished more easily as a consequence of the three dimensional colour-space.
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Affiliation(s)
- Toby Kurk
- School of Physics & Astronomy, University of Leeds, Leeds, West Yorkshire, United Kingdom.
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Abstract
At the cross-roads of nanoscience and microbiology, the nanoscale analysis of microbial cells using atomic force microscopy (AFM) is an exciting, rapidly evolving research field. Over the past decade, there has been tremendous progress in our use of AFM to observe membrane proteins and live cells at high resolution. Remarkable advances have also been made in applying force spectroscopy to manipulate single membrane proteins, to map surface properties and receptor sites on cells and to measure cellular interactions at the single-cell and single-molecule levels. In addition, recent developments in cantilever nanosensors have opened up new avenues for the label-free detection of microorganisms and bioanalytes.
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Affiliation(s)
- Yves F Dufrêne
- Unité de chimie des interfaces, Université catholique de Louvain, Croix du Sud 2/18, B-1348 Louvain-la-Neuve, Belgium.
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Vos M, Velicer GJ. Natural variation of gliding motility in a centimetre-scale population of Myxococcus xanthus. FEMS Microbiol Ecol 2008; 64:343-50. [DOI: 10.1111/j.1574-6941.2008.00484.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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