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Dornes A, Schmidt LM, Mais CN, Hook JC, Pané-Farré J, Kressler D, Thormann K, Bange G. Polar confinement of a macromolecular machine by an SRP-type GTPase. Nat Commun 2024; 15:5797. [PMID: 38987236 PMCID: PMC11236974 DOI: 10.1038/s41467-024-50274-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Accepted: 07/05/2024] [Indexed: 07/12/2024] Open
Abstract
The basal structure of the bacterial flagellum includes a membrane embedded MS-ring (formed by multiple copies of FliF) and a cytoplasmic C-ring (composed of proteins FliG, FliM and FliN). The SRP-type GTPase FlhF is required for directing the initial flagellar protein FliF to the cell pole, but the mechanisms are unclear. Here, we show that FlhF anchors developing flagellar structures to the polar landmark protein HubP/FimV, thereby restricting their formation to the cell pole. Specifically, the GTPase domain of FlhF interacts with HubP, while a structured domain at the N-terminus of FlhF binds to FliG. FlhF-bound FliG subsequently engages with the MS-ring protein FliF. Thus, the interaction of FlhF with HubP and FliG recruits a FliF-FliG complex to the cell pole. In addition, the modulation of FlhF activity by the MinD-type ATPase FlhG controls the interaction of FliG with FliM-FliN, thereby regulating the progression of flagellar assembly at the pole.
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Affiliation(s)
- Anita Dornes
- Philipps-University Marburg, Center for Synthetic Microbiology (SYNMIKRO) and Department of Chemistry, Hans-Meerwein-Strasse 6, C07, 35043, Marburg, Germany
| | - Lisa Marie Schmidt
- Justus-Liebig-Universität, Department of Microbiology and Molecular Biology, Heinrich-Buff-Ring 26, 35392, Giessen, Germany
| | - Christopher-Nils Mais
- Philipps-University Marburg, Center for Synthetic Microbiology (SYNMIKRO) and Department of Chemistry, Hans-Meerwein-Strasse 6, C07, 35043, Marburg, Germany
| | - John C Hook
- Justus-Liebig-Universität, Department of Microbiology and Molecular Biology, Heinrich-Buff-Ring 26, 35392, Giessen, Germany
| | - Jan Pané-Farré
- Philipps-University Marburg, Center for Synthetic Microbiology (SYNMIKRO) and Department of Chemistry, Hans-Meerwein-Strasse 6, C07, 35043, Marburg, Germany
| | - Dieter Kressler
- University of Fribourg, Department of Biology, Chemin du Musée 10, 1700, Fribourg, Switzerland
| | - Kai Thormann
- Justus-Liebig-Universität, Department of Microbiology and Molecular Biology, Heinrich-Buff-Ring 26, 35392, Giessen, Germany.
| | - Gert Bange
- Philipps-University Marburg, Center for Synthetic Microbiology (SYNMIKRO) and Department of Chemistry, Hans-Meerwein-Strasse 6, C07, 35043, Marburg, Germany.
- Max-Planck-Institute for terrestrial Microbiology, Molecular Physiology of Microbes, Karl-von-Frisch Strasse 14, 35043, Marburg, Germany.
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2
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Lee K, Han J. Analysis of the urine flow characteristics inside catheters for intermittent catheter selection. Sci Rep 2024; 14:13273. [PMID: 38858470 PMCID: PMC11164700 DOI: 10.1038/s41598-024-64395-9] [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: 12/19/2023] [Accepted: 06/07/2024] [Indexed: 06/12/2024] Open
Abstract
In this study, we conducted a numerical analysis on catheter sizes using computational fluid dynamics to assess urinary flow rates during intermittent catheterization (IC). The results revealed that the fluid (urine) movement within a catheter is driven by intravesical pressure, with friction against the catheter walls being the main hindrance to fluid movement. Higher-viscosity fluids experienced increased friction with increasing intravesical pressure, resulting in reduced fluid velocity, whereas lower-viscosity fluids experienced reduced friction under similar pressure, leading to increased fluid velocity. Regarding urine characteristics, the results indicated that bacteriuria, with lower viscosity, exhibited higher flow rates, whereas glucosuria exhibited the lowest flow rates. Additionally, velocity gradients decreased with increasing catheter diameters, reducing friction and enhancing fluid speed, while the friction increased with decreasing diameters, reducing fluid velocity. These findings confirm that flow rates increased with larger catheter sizes. Furthermore, in terms of specific gravity, the results showed that a 12Fr catheter did not meet the ISO-suggested average flow rate (50 cc/min). The significance of this study lies in its application of fluid dynamics to nursing, examining urinary flow characteristics in catheterization. It is expected to aid nurses in selecting appropriate catheters for intermittent catheterization based on urinary test results.
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Affiliation(s)
- Kyeongeun Lee
- College of Nursing Science, Kyung Hee University, Seoul, Republic of Korea
| | - Jeongwon Han
- College of Nursing Science, Kyung Hee University, Seoul, Republic of Korea.
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3
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Strnad M, Koizumi N, Nakamura S, Vancová M, Rego ROM. It's not all about flagella - sticky invasion by pathogenic spirochetes. Trends Parasitol 2024; 40:378-385. [PMID: 38523038 DOI: 10.1016/j.pt.2024.03.004] [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: 02/02/2024] [Revised: 03/07/2024] [Accepted: 03/12/2024] [Indexed: 03/26/2024]
Abstract
Pathogenic spirochetes cause a range of serious human diseases such as Lyme disease (LD), syphilis, leptospirosis, relapsing fever (RF), and periodontal disease. Motility is a critical virulence factor for spirochetes. From the mechanical perspective of the infection, it has been widely believed that flagella are the sole key players governing the migration and dissemination of these pathogens in the host. Here, we highlight the important contribution of spirochetal surface-exposed adhesive molecules and their dynamic interactions with host molecules in the process of infection, specifically in spirochetal swimming and crawling migration. We believe that these recent findings overturn the prevailing view depicting the spirochetal body to be just an inert elastic bag, which does not affect spirochetal cell locomotion.
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Affiliation(s)
- Martin Strnad
- Institute of Parasitology, Biology Centre CAS, Branišovská 31, 37005, České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 1760, 37005, České Budějovice, Czech Republic.
| | - Nobuo Koizumi
- Department of Bacteriology I, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Shuichi Nakamura
- Department of Applied Physics, Graduate School of Engineering, Tohoku University, 6-6-05 Aoba, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - Marie Vancová
- Institute of Parasitology, Biology Centre CAS, Branišovská 31, 37005, České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 1760, 37005, České Budějovice, Czech Republic
| | - Ryan O M Rego
- Institute of Parasitology, Biology Centre CAS, Branišovská 31, 37005, České Budějovice, Czech Republic; Faculty of Science, University of South Bohemia, Branišovská 1760, 37005, České Budějovice, Czech Republic
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4
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Jin C, Sengupta A. Microbes in porous environments: from active interactions to emergent feedback. Biophys Rev 2024; 16:173-188. [PMID: 38737203 PMCID: PMC11078916 DOI: 10.1007/s12551-024-01185-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 03/27/2024] [Indexed: 05/14/2024] Open
Abstract
Microbes thrive in diverse porous environments-from soil and riverbeds to human lungs and cancer tissues-spanning multiple scales and conditions. Short- to long-term fluctuations in local factors induce spatio-temporal heterogeneities, often leading to physiologically stressful settings. How microbes respond and adapt to such biophysical constraints is an active field of research where considerable insight has been gained over the last decades. With a focus on bacteria, here we review recent advances in self-organization and dispersal in inorganic and organic porous settings, highlighting the role of active interactions and feedback that mediates microbial survival and fitness. We discuss open questions and opportunities for using integrative approaches to advance our understanding of the biophysical strategies which microbes employ at various scales to make porous settings habitable.
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Affiliation(s)
- Chenyu Jin
- Physics of Living Matter Group, Department of Physics and Materials Science, University of Luxembourg, 162 A, Avenue de la Faïencerie, Luxembourg City, L-1511 Luxembourg
| | - Anupam Sengupta
- Physics of Living Matter Group, Department of Physics and Materials Science, University of Luxembourg, 162 A, Avenue de la Faïencerie, Luxembourg City, L-1511 Luxembourg
- Institute for Advanced Studies, University of Luxembourg, 2 Avenue de l’Université, Esch-sur-Alzette, L-4365 Luxembourg
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5
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Tani M, Wada H. How a Soft Rod Wraps around a Rotating Cylinder. PHYSICAL REVIEW LETTERS 2024; 132:058204. [PMID: 38364127 DOI: 10.1103/physrevlett.132.058204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 09/12/2023] [Accepted: 01/02/2024] [Indexed: 02/18/2024]
Abstract
The unique characteristics of helical coils are utilized in nature, manufacturing processes, and daily life. These coils are also pivotal in the development of soft machines, such as artificial muscles and soft grippers. The stability of these helical coils is generally dependent on the mechanical properties of the rods and geometry of the supporting objects. In this Letter, the shapes formed by a flexible, heavy rod wrapping around a slowly rotating rigid cylinder are investigated through a combination of experimental and theoretical approaches. Three distinct morphologies-tight coiling, helical wrapping, and no wrapping-are identified experimentally. These findings are rationalized by numerical simulations and a geometrically nonlinear Kirchhoff rod theory. Despite the frictional contact present, the local shape of the rod is explained by the interplay between bending elasticity, gravity, and the geometry of the system. Our Letter provides a comprehensive physical understanding of the ordered morphology of soft threads and rods. Implications of this understanding are significant for a wide range of phenomena, from the recently discovered wrapping motility mode of bacterial flagella to the design of an octopus-inspired soft gripper.
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Affiliation(s)
- Marie Tani
- Department of Physics, Tokyo Metropolitan University, Hachioji-City, Tokyo 192-0397, Japan
- Research Organization of Science and Technology, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
| | - Hirofumi Wada
- Department of Physical Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan
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Kinosita Y, Sowa Y. Flagellar polymorphism-dependent bacterial swimming motility in a structured environment. Biophys Physicobiol 2023; 20:e200024. [PMID: 37867560 PMCID: PMC10587448 DOI: 10.2142/biophysico.bppb-v20.0024] [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: 04/18/2023] [Accepted: 05/29/2023] [Indexed: 10/24/2023] Open
Abstract
Most motile bacteria use supramolecular motility machinery called bacterial flagellum, which converts the chemical energy gained from ion flux into mechanical rotation. Bacterial cells sense their external environment through a two-component regulatory system consisting of a histidine kinase and response regulator. Combining these systems allows the cells to move toward favorable environments and away from their repellents. A representative example of flagellar motility is run-and-tumble swimming in Escherichia coli, where the counter-clockwise (CCW) rotation of a flagellar bundle propels the cell forward, and the clockwise (CW) rotation undergoes cell re-orientation (tumbling) upon switching the direction of flagellar motor rotation from CCW to CW. In this mini review, we focus on several types of chemotactic behaviors that respond to changes in flagellar shape and direction of rotation. Moreover, our single-cell analysis demonstrated back-and-forth swimming motility of an original E. coli strain. We propose that polymorphic flagellar changes are required to enhance bacterial movement in a structured environment as a colony spread on an agar plate.
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Affiliation(s)
| | - Yoshiyuki Sowa
- Department of Frontier Bioscience, Hosei University, Tokyo 184-8584, Japan
- Research Center for Micro-Nano Technology, Hosei University, Tokyo 184-8584, Japan
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7
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Zhang X, Zhang C, Zhang R, Yuan J. Differential Bending Stiffness of the Bacterial Flagellar Hook under Counterclockwise and Clockwise Rotations. PHYSICAL REVIEW LETTERS 2023; 130:138401. [PMID: 37067319 DOI: 10.1103/physrevlett.130.138401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 03/09/2023] [Indexed: 06/19/2023]
Abstract
The bacterial hook, as a universal joint coupling rotation of the flagellar motor and the filament, is an important component of the flagellum that propels the bacteria to swim. The mechanical properties of the hook are essential for the flagellum to achieve normal functions. In multiflagellated bacteria such as Escherichia coli, the hook must be compliant so that it can bend for the filaments to form a coherently rotating bundle to generate the thrust when the motor rotates counterclockwise (CCW), yet it also must be rigid so that the bundle can disrupt for the bacteria to tumble to change swimming direction when the motor rotates clockwise (CW). Here, by combining an elastic rod model with high-resolution bead assay to accurately measure the bending stiffness of the hook under CCW or CW rotation in vivo, we elucidate how the hook accomplishes this dual functionality: the hook stiffens under CW rotation, with bending stiffness under CW rotation twice as large as that under CCW rotation. This enables a robust run-and-tumble swimming motility for multiflagellated bacteria.
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Affiliation(s)
- Xinwen Zhang
- Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Chi Zhang
- Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Rongjing Zhang
- Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Junhua Yuan
- Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
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8
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Manoj KM, Jacob VD, Kavdia M, Tamagawa H, Jaeken L, Soman V. Questioning rotary functionality in the bacterial flagellar system and proposing a murburn model for motility. J Biomol Struct Dyn 2023; 41:15691-15714. [PMID: 36970840 DOI: 10.1080/07391102.2023.2191146] [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: 11/29/2022] [Accepted: 03/09/2023] [Indexed: 03/29/2023]
Abstract
Bacterial flagellar system (BFS) was the primary example of a purported 'rotary-motor' functionality in a natural assembly. This mandates the translation of a circular motion of components inside into a linear displacement of the cell body outside, which is supposedly orchestrated with the following features of the BFS: (i) A chemical/electrical differential generates proton motive force (pmf, including a trans-membrane potential, TMP), which is electro-mechanically transduced by inward movement of protons via BFS. (ii) Membrane-bound proteins of BFS serve as stators and the slender filament acts as an external propeller, culminating into a hook-rod that pierces the membrane to connect to a 'broader assembly of deterministically movable rotor'. We had disclaimed the purported pmf/TMP-based respiratory/photosynthetic physiology involving Complex V, which was also perceived as a 'rotary machine' earlier. We pointed out that the murburn redox logic was operative therein. We pursue the following similar perspectives in BFS-context: (i) Low probability for the evolutionary attainment of an ordered/synchronized teaming of about two dozen types of proteins (assembled across five-seven distinct phases) towards the singular agendum of rotary motility. (ii) Vital redox activity (not the gambit of pmf/TMP!) powers the molecular and macroscopic activities of cells, including flagella. (iii) Flagellar movement is noted even in ambiances lacking/countering the directionality mandates sought by pmf/TMP. (iv) Structural features of BFS lack component(s) capable of harnessing/achieving pmf/TMP and functional rotation. A viable murburn model for conversion of molecular/biochemical activity into macroscopic/mechanical outcomes is proposed herein for understanding BFS-assisted motility. HIGHLIGHTSThe motor-like functionalism of bacterial flagellar system (BFS) is analyzedProton/Ion-differential based powering of BFS is unviable in bacteriaUncouplers-sponsored effects were misinterpreted, resulting in a detour in BFS researchThese findings mandate new explanation for nano-bio-mechanical movements in BFSA minimalist murburn model for the bacterial flagella-aided movement is proposedCommunicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Kelath Murali Manoj
- Satyamjayatu, The Science & Ethics Foundation, Palakkad District, Kerala, India
| | - Vivian David Jacob
- Satyamjayatu, The Science & Ethics Foundation, Palakkad District, Kerala, India
| | - Mahendra Kavdia
- Department of Biomedical Engineering, Wayne State University, Detroit, Michigan, USA
| | - Hirohisa Tamagawa
- Department of Mechanical Engineering, Gifu University, Gifu City, Japan
| | - Laurent Jaeken
- Department of Industrial Sciences and Technology, Karel de Grote-Hogeschool, Antwerp University Association, Belgium
| | - Vidhu Soman
- Department of Bioscience & Bioengineering, IIT Bombay (& DSS Imagetech Pvt. Ltd), Mumbai, Maharashtra, India
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9
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Mo S, Tang K, Liao Q, Xie L, Wu Y, Wang G, Ruan Q, Gao A, Lv Y, Cai K, Tong L, Wu Z, Chu PK, Wang H. Tuning the arrangement of lamellar nanostructures: achieving the dual function of physically killing bacteria and promoting osteogenesis. MATERIALS HORIZONS 2023; 10:881-888. [PMID: 36537031 DOI: 10.1039/d2mh01147f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Bacteria killing behavior based on physical effects is preferred for biomedical implants because of the negligible associated side effects. However, our current understanding of the antibacterial activity of nanostructures remains limited and, in practice, nanoarchitectures that are created on orthopedics should also promote osteogenesis simultaneously. In this study, tilted and vertical nanolamellar structures are fabricated on semi-crystalline polyether-ether-ketone (PEEK) via argon plasma treatment with or without pre-annealing. The two types of nanolamellae can physically kill the bacteria that come into contact with them, but the antibacterial mechanisms between the two are different. Specifically, the sharp edges of the vertically aligned nanolamellae can penetrate and damage the bacterial membrane, whereas bacteria are stuck on the tilted nanostructures and are stretched, leading to eventual destruction. The tilted nanolamellae are more desirable than the vertically aligned ones from the perspective of peri-implant bone regeneration. Our study not only reveals the role of the arrangement of nanostructures in orthopedic applications but also provides new information about different mechanisms of physical antibacterial activity.
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Affiliation(s)
- Shi Mo
- Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.
- Department of Physics, Department of Materials Science and Engineering, and Department of Biomedical Engineering, City University of Hong Kong, Tat Chee Avene, Kowloon, Hong Kong, China
| | - Kaiwei Tang
- Department of Physics, Department of Materials Science and Engineering, and Department of Biomedical Engineering, City University of Hong Kong, Tat Chee Avene, Kowloon, Hong Kong, China
- School of Materials Science and Engineering, Xiangtan University, Xiangtan, China
| | - Qing Liao
- Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.
| | - Lingxia Xie
- Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.
| | - Yuzheng Wu
- Department of Physics, Department of Materials Science and Engineering, and Department of Biomedical Engineering, City University of Hong Kong, Tat Chee Avene, Kowloon, Hong Kong, China
| | - Guomin Wang
- Department of Physics, Department of Materials Science and Engineering, and Department of Biomedical Engineering, City University of Hong Kong, Tat Chee Avene, Kowloon, Hong Kong, China
| | - Qingdong Ruan
- Department of Physics, Department of Materials Science and Engineering, and Department of Biomedical Engineering, City University of Hong Kong, Tat Chee Avene, Kowloon, Hong Kong, China
| | - Ang Gao
- Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.
| | - Yuanliang Lv
- Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.
- School of Advanced Manufacturing, Fuzhou University, Fuzhou, China
| | - Kaiyong Cai
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, China
| | - Liping Tong
- Department of Physics, Department of Materials Science and Engineering, and Department of Biomedical Engineering, City University of Hong Kong, Tat Chee Avene, Kowloon, Hong Kong, China
| | - Zhengwei Wu
- Department of Physics, Department of Materials Science and Engineering, and Department of Biomedical Engineering, City University of Hong Kong, Tat Chee Avene, Kowloon, Hong Kong, China
- School of Nuclear Science and Technology, University of Science and Technology of China, Hefei, China.
| | - Paul K Chu
- Department of Physics, Department of Materials Science and Engineering, and Department of Biomedical Engineering, City University of Hong Kong, Tat Chee Avene, Kowloon, Hong Kong, China
| | - Huaiyu Wang
- Institute of Biomedicine and Biotechnology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.
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Role of the Two Flagellar Stators in Swimming Motility of Pseudomonas putida. mBio 2022; 13:e0218222. [PMID: 36409076 PMCID: PMC9765564 DOI: 10.1128/mbio.02182-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
In the soil bacterium Pseudomonas putida, the motor torque for flagellar rotation is generated by the two stators MotAB and MotCD. Here, we construct mutant strains in which one or both stators are knocked out and investigate their swimming motility in fluids of different viscosity and in heterogeneous structured environments (semisolid agar). Besides phase-contrast imaging of single-cell trajectories and spreading cultures, dual-color fluorescence microscopy allows us to quantify the role of the stators in enabling P. putida's three different swimming modes, where the flagellar bundle pushes, pulls, or wraps around the cell body. The MotAB stator is essential for swimming motility in liquids, while spreading in semisolid agar is not affected. Moreover, if the MotAB stator is knocked out, wrapped mode formation under low-viscosity conditions is strongly impaired and only partly restored for increased viscosity and in semisolid agar. In contrast, when the MotCD stator is missing, cells are indistinguishable from the wild type in fluid experiments but spread much more slowly in semisolid agar. Analysis of the microscopic trajectories reveals that the MotCD knockout strain forms sessile clusters, thereby reducing the number of motile cells, while the swimming speed is unaffected. Together, both stators ensure a robust wild type that swims efficiently under different environmental conditions. IMPORTANCE Because of its heterogeneous habitat, the soil bacterium Pseudomonas putida needs to swim efficiently under very different environmental conditions. In this paper, we knocked out the stators MotAB and MotCD to investigate their impact on the swimming motility of P. putida. While the MotAB stator is crucial for swimming in fluids, in semisolid agar, both stators are sufficient to sustain a fast-swimming phenotype and increased frequencies of the wrapped mode, which is known to be beneficial for escaping mechanical traps. However, in contrast to the MotAB knockout, a culture of MotCD knockout cells spreads much more slowly in the agar, as it forms nonmotile clusters that reduce the number of motile cells.
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11
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Kühn MJ, Edelmann DB, Thormann KM. Polar flagellar wrapping and lateral flagella jointly contribute to Shewanella putrefaciens environmental spreading. Environ Microbiol 2022; 24:5911-5923. [PMID: 35722744 DOI: 10.1111/1462-2920.16107] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 06/10/2022] [Accepted: 06/17/2022] [Indexed: 01/12/2023]
Abstract
Flagella enable bacteria to actively spread within the environment. A number of species possess two separate flagellar systems, where in most cases a primary polar flagellar system is supported by distinct secondary lateral flagella under appropriate conditions. Using functional fluorescence tagging on one of these species, Shewanella putrefaciens, as a model system, we explored how two different flagellar systems can exhibit efficient joint function. The S. putrefaciens secondary flagellar filaments are composed as a mixture of two highly homologous non-glycosylated flagellins, FlaA2 and FlaB2 . Both are solely sufficient to form a functional filament, however, full spreading motility through soft agar requires both flagellins. During swimming, lateral flagella emerge from the cell surface at angles between 30° and 50°, and only filaments located close to the cell pole may form a bundle. Upon a directional shift from forward to backward swimming initiated by the main polar flagellum, the secondary filaments flip over and thus support propulsion into either direction. Lateral flagella do not inhibit the wrapping of the polar flagellum around the cell body at high load. Accordingly, screw thread-like motility mediated by the primary flagellum and activity of lateral flagella cumulatively supports spreading through constricted environments such as polysaccharide matrices.
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Affiliation(s)
- Marco J Kühn
- Institut für Mikrobiologie und Molekularbiologie, Justus-Liebig-Universität Gießen, Gießen, Germany.,Institute of Bioengineering and Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Daniel B Edelmann
- Institut für Mikrobiologie und Molekularbiologie, Justus-Liebig-Universität Gießen, Gießen, Germany
| | - Kai M Thormann
- Institut für Mikrobiologie und Molekularbiologie, Justus-Liebig-Universität Gießen, Gießen, Germany
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12
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Schwan M, Khaledi A, Willger S, Papenfort K, Glatter T, Häußler S, Thormann KM. FlrA-independent production of flagellar proteins is required for proper flagellation in Shewanella putrefaciens. Mol Microbiol 2022; 118:670-682. [PMID: 36285560 DOI: 10.1111/mmi.14993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/13/2022] [Accepted: 10/17/2022] [Indexed: 01/18/2023]
Abstract
Flagella are multiprotein complexes whose assembly and positioning require complex spatiotemporal control. Flagellar assembly is thought to be controlled by several transcriptional tiers, which are mediated through various master regulators. Here, we revisited the regulation of flagellar genes in polarly flagellated gammaproteobacteria by the regulators FlrA, RpoN (σ54 ) and FliA (σ28 ) in Shewanella putrefaciens CN-32 at the transcript and protein level. We found that a number of regulatory and structural proteins were present in the absence of the main regulators, suggesting that initiation of flagella assembly and motor activation relies on the abundance control of only a few structural key components that are required for the formation of the MS- and C-ring and the flagellar type III secretion system. We identified FlrA-independent promoters driving expression of the regulators of flagellar number and positioning, FlhF and FlhG. Reduction of the gene expression levels from these promoters resulted in the emergence of hyperflagellation. This finding indicates that basal expression is required to adjust the flagellar counter in Shewanella. This is adding a deeper layer to the regulation of flagellar synthesis and assembly.
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Affiliation(s)
- Meike Schwan
- Institute of Microbiology and Molecular Biology, Justus-Liebig-Universität, Giessen, Germany
| | - Ariane Khaledi
- Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Sven Willger
- Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Kai Papenfort
- Institute for Microbiology, Friedrich Schiller University, Jena, Germany
| | - Timo Glatter
- Max Planck Institute for Terrestrial Microbiology, Mass Spectrometry and Proteomics, Marburg, Germany
| | - Susanne Häußler
- Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Kai M Thormann
- Institute of Microbiology and Molecular Biology, Justus-Liebig-Universität, Giessen, Germany
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13
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Active Colloids on Fluid Interfaces. Curr Opin Colloid Interface Sci 2022. [DOI: 10.1016/j.cocis.2022.101629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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14
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Codutti A, Charsooghi MA, Cerdá-Doñate E, Taïeb HM, Robinson T, Faivre D, Klumpp S. Interplay of surface interaction and magnetic torque in single-cell motion of magnetotactic bacteria in microfluidic confinement. eLife 2022; 11:71527. [PMID: 35852850 PMCID: PMC9365388 DOI: 10.7554/elife.71527] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 07/18/2022] [Indexed: 11/21/2022] Open
Abstract
Swimming microorganisms often experience complex environments in their natural habitat. The same is true for microswimmers in envisioned biomedical applications. The simple aqueous conditions typically studied in the lab differ strongly from those found in these environments and often exclude the effects of small volume confinement or the influence that external fields have on their motion. In this work, we investigate magnetically steerable microswimmers, specifically magnetotactic bacteria, in strong spatial confinement and under the influence of an external magnetic field. We trap single cells in micrometer-sized microfluidic chambers and track and analyze their motion, which shows a variety of different trajectories, depending on the chamber size and the strength of the magnetic field. Combining these experimental observations with simulations using a variant of an active Brownian particle model, we explain the variety of trajectories by the interplay between the wall interactions and the magnetic torque. We also analyze the pronounced cell-to-cell heterogeneity, which makes single-cell tracking essential for an understanding of the motility patterns. In this way, our work establishes a basis for the analysis and prediction of microswimmer motility in more complex environments.
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Affiliation(s)
- Agnese Codutti
- Biomaterials Department, Max Planck Institute of Colloids and Interfaces
| | | | - Elisa Cerdá-Doñate
- Biomaterials Department, Max Planck Institute of Colloids and Interfaces
| | - Hubert M Taïeb
- Biomaterials Department, Max Planck Institute of Colloids and Interfaces
| | - Tom Robinson
- Theory and Bio‐systems Department, Max Planck Institute of Colloids and Interfaces
| | | | - Stefan Klumpp
- Institute for the Dynamics of Complex Systems, University of Göttingen
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15
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Lynch JB, James N, McFall-Ngai M, Ruby EG, Shin S, Takagi D. Transitioning to confined spaces impacts bacterial swimming and escape response. Biophys J 2022; 121:2653-2662. [PMID: 35398019 PMCID: PMC9300662 DOI: 10.1016/j.bpj.2022.04.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 12/28/2021] [Accepted: 04/05/2022] [Indexed: 11/02/2022] Open
Abstract
Symbiotic bacteria often navigate complex environments before colonizing privileged sites in their host organism. Chemical gradients are known to facilitate directional taxis of these bacteria, guiding them toward their eventual destination. However, less is known about the role of physical features in shaping the path the bacteria take and defining how they traverse a given space. The flagellated marine bacterium Vibrio fischeri, which forms a binary symbiosis with the Hawaiian bobtail squid, Euprymna scolopes, must navigate tight physical confinement during colonization, squeezing through a tissue bottleneck constricting to ∼2 μm in width on the way to its eventual home. Using microfluidic in vitro experiments, we discovered that V. fischeri cells alter their behavior upon entry into confined space, straightening their swimming paths and promoting escape from confinement. Using a computational model, we attributed this escape response to two factors: reduced directional fluctuation and a refractory period between reversals. Additional experiments in asymmetric capillary tubes confirmed that V. fischeri quickly escape from confined ends, even when drawn into the ends by chemoattraction. This avoidance was apparent down to a limit of confinement approaching the diameter of the cell itself, resulting in a balance between chemoattraction and evasion of physical confinement. Our findings demonstrate that nontrivial distributions of swimming bacteria can emerge from simple physical gradients in the level of confinement. Tight spaces may serve as an additional, crucial cue for bacteria while they navigate complex environments to enter specific habitats.
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Affiliation(s)
- Jonathan B Lynch
- Pacific Biosciences Research Center, University of Hawai'i at Mānoa, Honolulu, Hawai'i.
| | - Nicholas James
- Department of Cell and Molecular Biology, University of Hawai'i at Mānoa, Honolulu, Hawai'i
| | - Margaret McFall-Ngai
- Pacific Biosciences Research Center, University of Hawai'i at Mānoa, Honolulu, Hawai'i
| | - Edward G Ruby
- Pacific Biosciences Research Center, University of Hawai'i at Mānoa, Honolulu, Hawai'i
| | - Sangwoo Shin
- Department of Mechanical Engineering, University of Hawai'i at Mānoa, Honolulu, Hawai'i; Department of Mechanical and Aerospace Engineering, University at Buffalo, Buffalo, New York
| | - Daisuke Takagi
- Pacific Biosciences Research Center, University of Hawai'i at Mānoa, Honolulu, Hawai'i; Department of Mechanical Engineering, University of Hawai'i at Mānoa, Honolulu, Hawai'i; Department of Mathematics, University of Hawai'i at Mānoa, Honolulu, Hawai'i
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16
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Abstract
The concept of creating all-mechanical soft microrobotic systems has great potential to address outstanding challenges in biomedical applications, and introduce more sustainable and multifunctional products. To this end, magnetic fields and light have been extensively studied as potential energy sources. On the other hand, coupling the response of materials to pressure waves has been overlooked despite the abundant use of acoustics in nature and engineering solutions. In this study, we show that programmed commands can be contained on 3D nanoprinted polymer systems with the introduction of selectively excited air bubbles and rationally designed compliant mechanisms. A repertoire of micromechanical systems is engineered using experimentally validated computational models that consider the effects of primary and secondary pressure fields on entrapped air bubbles and the surrounding fluid. Coupling the dynamics of bubble oscillators reveals rich acoustofluidic interactions that can be programmed in space and time. We prescribe kinematics by harnessing the forces generated through these interactions to deform structural elements, which can be remotely reconfigured on demand with the incorporation of mechanical switches. These basic actuation and analog control modules will serve as the building blocks for the development of a novel class of micromechanical systems powered and programmed by acoustic signals.
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Affiliation(s)
- Murat Kaynak
- Institute of Mechanical Engineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Amit Dolev
- Institute of Mechanical Engineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Mahmut Selman Sakar
- Institute of Mechanical Engineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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17
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Abstract
A huge number of bacterial species are motile by flagella, which allow them to actively move toward favorable environments and away from hazardous areas and to conquer new habitats. The general perception of flagellum-mediated movement and chemotaxis is dominated by the Escherichia coli paradigm, with its peritrichous flagellation and its famous run-and-tumble navigation pattern, which has shaped the view on how bacteria swim and navigate in chemical gradients. However, a significant amount-more likely the majority-of bacterial species exhibit a (bi)polar flagellar localization pattern instead of lateral flagella. Accordingly, these species have evolved very different mechanisms for navigation and chemotaxis. Here, we review the earlier and recent findings on the various modes of motility mediated by polar flagella. Expected final online publication date for the Annual Review of Microbiology, Volume 76 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Kai M Thormann
- Institute of Microbiology and Molecular Biology, Justus Liebig University Gießen, Gießen, Germany;
| | - Carsten Beta
- Institute of Physics and Astronomy, University of Potsdam, Potsdam, Germany;
| | - Marco J Kühn
- Institute of Bioengineering and Global Health Institute, School of Life Sciences, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland;
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18
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Thormann KM. Dynamic Hybrid Flagellar Motors-Fuel Switch and More. Front Microbiol 2022; 13:863804. [PMID: 35495728 PMCID: PMC9039648 DOI: 10.3389/fmicb.2022.863804] [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: 01/27/2022] [Accepted: 02/25/2022] [Indexed: 11/13/2022] Open
Abstract
Flagellar motors are intricate rotating nanomachines that are powered by transmembrane ion gradients. The stator complexes are the powerhouses of the flagellar motor: They convert a transmembrane ion gradient, mainly of H+ or Na+, into rotation of the helical flagellar filament. They are thus essential for motor function. The number of stators synchronously engaged in the motor is surprisingly dynamic and depends on the load and the environmental concentration of the corresponding coupling ion. Thus, the rotor-stator interactions determine an important part of the properties of the motor. Numerous bacteria have been identified as possessing more than one set of stators, and some species have been demonstrated to use these different stators in various configurations to modify motor functions by dynamic in-flight swapping. Here, we review knowledge of the properties, the functions, and the evolution of these hybrid motors and discuss questions that remain unsolved.
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Affiliation(s)
- Kai M Thormann
- Fachbereich für Chemie und Biologie, Institut für Mikrobiologie und Molekularbiologie, Justus-Liebig-Universität Gießen, Gießen, Germany
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19
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Rick T, Kreiling V, Höing A, Fiedler S, Glatter T, Steinchen W, Hochberg G, Bähre H, Seifert R, Bange G, Knauer SK, Graumann PL, Thormann KM. GGDEF domain as spatial on-switch for a phosphodiesterase by interaction with landmark protein HubP. NPJ Biofilms Microbiomes 2022; 8:35. [PMID: 35501424 PMCID: PMC9061725 DOI: 10.1038/s41522-022-00297-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 03/31/2022] [Indexed: 11/09/2022] Open
Abstract
AbstractIn bacteria, the monopolar localization of enzymes and protein complexes can result in a bimodal distribution of enzyme activity between the dividing cells and heterogeneity of cellular behaviors. In Shewanella putrefaciens, the multidomain hybrid diguanylate cyclase/phosphodiesterase PdeB, which degrades the secondary messenger c-di-GMP, is located at the flagellated cell pole. Here, we show that direct interaction between the inactive diguanylate cyclase (GGDEF) domain of PdeB and the FimV domain of the polar landmark protein HubP is crucial for full function of PdeB as a phosphodiesterase. Thus, the GGDEF domain serves as a spatially controlled on-switch that effectively restricts PdeBs activity to the flagellated cell pole. PdeB regulates abundance and activity of at least two crucial surface-interaction factors, the BpfA surface-adhesion protein and the MSHA type IV pilus. The heterogeneity in c-di-GMP concentrations, generated by differences in abundance and timing of polar appearance of PdeB, orchestrates the population behavior with respect to cell-surface interaction and environmental spreading.
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20
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Park J, Kim Y, Lee W, Lim S. Modeling of lophotrichous bacteria reveals key factors for swimming reorientation. Sci Rep 2022; 12:6482. [PMID: 35444244 PMCID: PMC9021275 DOI: 10.1038/s41598-022-09823-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 03/25/2022] [Indexed: 11/16/2022] Open
Abstract
Lophotrichous bacteria swim through fluid by rotating their flagellar bundle extended collectively from one pole of the cell body. Cells experience modes of motility such as push, pull, and wrapping, accompanied by pauses of motor rotation in between. We present a mathematical model of a lophotrichous bacterium and investigate the hydrodynamic interaction of cells to understand their swimming mechanism. We classify the swimming modes which vary depending on the bending modulus of the hook and the magnitude of applied torques on the motor. Given the hook’s bending modulus, we find that there exist corresponding critical thresholds of the magnitude of applied torques that separate wrapping from pull in CW motor rotation, and overwhirling from push in CCW motor rotation, respectively. We also investigate reoriented directions of cells in three-dimensional perspectives as the cell experiences different series of swimming modes. Our simulations show that the transition from a wrapping mode to a push mode and pauses in between are key factors to determine a new path and that the reoriented direction depends upon the start time and duration of the pauses. It is also shown that the wrapping mode may help a cell to escape from the region where the cell is trapped near a wall.
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Affiliation(s)
- Jeungeun Park
- Department of Mathematical Sciences, University of Cincinnati, Cincinnati, OH, 45221, USA
| | - Yongsam Kim
- Department of Mathematics, Chung-Ang University, Seoul, 06974, Republic of Korea.
| | - Wanho Lee
- National Institute for Mathematical Sciences, Daejeon, 34047, Republic of Korea
| | - Sookkyung Lim
- Department of Mathematical Sciences, University of Cincinnati, Cincinnati, OH, 45221, USA.
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21
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Abstract
SignificanceThe monotrichous Pseudomonas aeruginosa was usually thought to swim in a pattern of "run and reverse" (possibly with pauses in between), where straight runs alternated with reverses with angular changes of swimming direction near 180°. Here, by simultaneously tracking the cell swimming and the morphology of its flagellum, we discovered a swimming mode in P. aeruginosa-the wrap mode, during which the flagellar filament wrapped around the cell body and induced large fluctuation of the body orientation. The wrap mode randomized swimming direction, resulting in a broad distribution of angular changes over 0 to 180° with a peak near 90°. This allowed the bacterium to explore the environment more efficiently, which we confirmed by stochastic simulations of P. aeruginosa chemotaxis.
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22
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Palma V, Gutiérrez MS, Vargas O, Parthasarathy R, Navarrete P. Methods to Evaluate Bacterial Motility and Its Role in Bacterial–Host Interactions. Microorganisms 2022; 10:microorganisms10030563. [PMID: 35336138 PMCID: PMC8953368 DOI: 10.3390/microorganisms10030563] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 02/02/2022] [Accepted: 02/06/2022] [Indexed: 11/16/2022] Open
Abstract
Bacterial motility is a widespread characteristic that can provide several advantages for the cell, allowing it to move towards more favorable conditions and enabling host-associated processes such as colonization. There are different bacterial motility types, and their expression is highly regulated by the environmental conditions. Because of this, methods for studying motility under realistic experimental conditions are required. A wide variety of approaches have been developed to study bacterial motility. Here, we present the most common techniques and recent advances and discuss their strengths as well as their limitations. We classify them as macroscopic or microscopic and highlight the advantages of three-dimensional imaging in microscopic approaches. Lastly, we discuss methods suited for studying motility in bacterial–host interactions, including the use of the zebrafish model.
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Affiliation(s)
- Victoria Palma
- Laboratory of Microbiology and Probiotics, Institute of Nutrition and Food Technology (INTA), University of Chile, El Líbano 5524, Santiago 7830490, Chile; (V.P.); (M.S.G.); (O.V.)
| | - María Soledad Gutiérrez
- Laboratory of Microbiology and Probiotics, Institute of Nutrition and Food Technology (INTA), University of Chile, El Líbano 5524, Santiago 7830490, Chile; (V.P.); (M.S.G.); (O.V.)
- Millennium Science Initiative Program, Milenium Nucleus in the Biology of the Intestinal Microbiota, National Agency for Research and Development (ANID), Moneda 1375, Santiago 8200000, Chile
| | - Orlando Vargas
- Laboratory of Microbiology and Probiotics, Institute of Nutrition and Food Technology (INTA), University of Chile, El Líbano 5524, Santiago 7830490, Chile; (V.P.); (M.S.G.); (O.V.)
| | - Raghuveer Parthasarathy
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA;
- Department of Physics and Materials Science Institute, University of Oregon, Eugene, OR 97403, USA
| | - Paola Navarrete
- Laboratory of Microbiology and Probiotics, Institute of Nutrition and Food Technology (INTA), University of Chile, El Líbano 5524, Santiago 7830490, Chile; (V.P.); (M.S.G.); (O.V.)
- Millennium Science Initiative Program, Milenium Nucleus in the Biology of the Intestinal Microbiota, National Agency for Research and Development (ANID), Moneda 1375, Santiago 8200000, Chile
- Correspondence:
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23
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Pecina A, Schwan M, Blagotinsek V, Rick T, Klüber P, Leonhard T, Bange G, Thormann KM. The Stand-Alone PilZ-Domain Protein MotL Specifically Regulates the Activity of the Secondary Lateral Flagellar System in Shewanella putrefaciens. Front Microbiol 2021; 12:668892. [PMID: 34140945 PMCID: PMC8203827 DOI: 10.3389/fmicb.2021.668892] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 04/19/2021] [Indexed: 11/13/2022] Open
Abstract
A number of bacterial species control the function of the flagellar motor in response to the levels of the secondary messenger c-di-GMP, which is often mediated by c-di-GMP-binding proteins that act as molecular brakes or clutches to slow the motor rotation. The gammaproteobacterium Shewanella putrefaciens possesses two distinct flagellar systems, the primary single polar flagellum and a secondary system with one to five lateral flagellar filaments. Here, we identified a protein, MotL, which specifically regulates the activity of the lateral, but not the polar, flagellar motors in response to the c-di-GMP levels. MotL only consists of a single PilZ domain binding c-di-GMP, which is crucial for its function. Deletion and overproduction analyses revealed that MotL slows down the lateral flagella at elevated levels of c-di-GMP, and may speed up the lateral flagellar-mediated movement at low c-di-GMP concentrations. In vitro interaction studies hint at an interaction of MotL with the C-ring of the lateral flagellar motors. This study shows a differential c-di-GMP-dependent regulation of the two flagellar systems in a single species, and implicates that PilZ domain-only proteins can also act as molecular regulators to control the flagella-mediated motility in bacteria.
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Affiliation(s)
- Anna Pecina
- Department of Microbiology and Molecular Biology, Justus-Liebig-Universität Gießen, Giessen, Germany
| | - Meike Schwan
- Department of Microbiology and Molecular Biology, Justus-Liebig-Universität Gießen, Giessen, Germany
| | - Vitan Blagotinsek
- Department of Chemistry, SYNMIKRO Research Center, Philipps-University Marburg, Marburg, Germany
| | - Tim Rick
- Department of Microbiology and Molecular Biology, Justus-Liebig-Universität Gießen, Giessen, Germany
| | - Patrick Klüber
- Department of Microbiology and Molecular Biology, Justus-Liebig-Universität Gießen, Giessen, Germany
| | - Tabea Leonhard
- Department of Microbiology and Molecular Biology, Justus-Liebig-Universität Gießen, Giessen, Germany
| | - Gert Bange
- Department of Chemistry, SYNMIKRO Research Center, Philipps-University Marburg, Marburg, Germany
| | - Kai M Thormann
- Department of Microbiology and Molecular Biology, Justus-Liebig-Universität Gießen, Giessen, Germany
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24
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Ren Z, Zhang R, Soon RH, Liu Z, Hu W, Onck PR, Sitti M. Soft-bodied adaptive multimodal locomotion strategies in fluid-filled confined spaces. SCIENCE ADVANCES 2021; 7:eabh2022. [PMID: 34193416 PMCID: PMC8245043 DOI: 10.1126/sciadv.abh2022] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 05/17/2021] [Indexed: 05/06/2023]
Abstract
Soft-bodied locomotion in fluid-filled confined spaces is critical for future wireless medical robots operating inside vessels, tubes, channels, and cavities of the human body, which are filled with stagnant or flowing biological fluids. However, the active soft-bodied locomotion is challenging to achieve when the robot size is comparable with the cross-sectional dimension of these confined spaces. Here, we propose various control and performance enhancement strategies to let the sheet-shaped soft millirobots achieve multimodal locomotion, including rolling, undulatory crawling, undulatory swimming, and helical surface crawling depending on different fluid-filled confined environments. With these locomotion modes, the sheet-shaped soft robot can navigate through straight or bent gaps with varying sizes, tortuous channels, and tubes with a flowing fluid inside. Such soft robot design along with its control and performance enhancement strategies are promising to be applied in future wireless soft medical robots inside various fluid-filled tight regions of the human body.
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Affiliation(s)
- Ziyu Ren
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569 Stuttgart, Germany
- Institute for Biomedical Engineering, ETH Zürich, 8092 Zürich, Switzerland
| | - Rongjing Zhang
- Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, Netherlands
| | - Ren Hao Soon
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569 Stuttgart, Germany
- Institute for Biomedical Engineering, ETH Zürich, 8092 Zürich, Switzerland
| | - Zemin Liu
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569 Stuttgart, Germany
- Institute for Biomedical Engineering, ETH Zürich, 8092 Zürich, Switzerland
| | - Wenqi Hu
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569 Stuttgart, Germany.
| | - Patrick R Onck
- Zernike Institute for Advanced Materials, University of Groningen, 9747 AG Groningen, Netherlands.
| | - Metin Sitti
- Physical Intelligence Department, Max Planck Institute for Intelligent Systems, 70569 Stuttgart, Germany.
- Institute for Biomedical Engineering, ETH Zürich, 8092 Zürich, Switzerland
- School of Medicine and College of Engineering, Koç University, 34450 Istanbul, Turkey
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25
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Grognot M, Taute KM. More than propellers: how flagella shape bacterial motility behaviors. Curr Opin Microbiol 2021; 61:73-81. [PMID: 33845324 DOI: 10.1016/j.mib.2021.02.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 02/05/2021] [Accepted: 02/14/2021] [Indexed: 12/22/2022]
Abstract
Bacteria use a wide variety of flagellar architectures to navigate their environment. While the iconic run-tumble motility strategy of the peritrichously flagellated Escherichia coli has been well studied, recent work has revealed a variety of new motility behaviors that can be achieved with different flagellar architectures, such as single, bundled, or opposing polar flagella. The recent discovery of various flagellar gymnastics such as flicking and flagellar wrapping is increasingly shifting the view from flagella as passive propellers to versatile appendages that can be used in a wide range of conformations. Here, we review recent observations of how flagella shape motility behaviors and summarize the nascent structure-function map linking flagellation and behavior.
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Affiliation(s)
- Marianne Grognot
- Rowland Institute at Harvard, 100 Edwin H Land Blvd, Cambridge, MA 02142, USA
| | - Katja M Taute
- Rowland Institute at Harvard, 100 Edwin H Land Blvd, Cambridge, MA 02142, USA.
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26
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Mohammadinejad S, Faivre D, Klumpp S. Stokesian dynamics simulations of a magnetotactic bacterium. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2021; 44:40. [PMID: 33759003 PMCID: PMC7987682 DOI: 10.1140/epje/s10189-021-00038-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 02/15/2021] [Indexed: 05/13/2023]
Abstract
The swimming of bacteria provides insight into propulsion and steering under the conditions of low-Reynolds number hydrodynamics. Here we address the magnetically steered swimming of magnetotactic bacteria. We use Stokesian dynamics simulations to study the swimming of single-flagellated magnetotactic bacteria (MTB) in an external magnetic field. Our model MTB consists of a spherical cell body equipped with a magnetic dipole moment and a helical flagellum rotated by a rotary motor. The elasticity of the flagellum as well as magnetic and hydrodynamic interactions is taken into account in this model. We characterized how the swimming velocity is dependent on parameters of the model. We then studied the U-turn motion after a field reversal and found two regimes for weak and strong fields and, correspondingly, two characteristic time scales. In the two regimes, the U-turn time is dominated by the turning of the cell body and its magnetic moment or the turning of the flagellum, respectively. In the regime for weak fields, where turning is dominated by the magnetic relaxation, the U-turn time is approximately in agreement with a theoretical model based on torque balance. In the strong-field regime, strong deformations of the flagellum are observed. We further simulated the swimming of a bacterium with a magnetic moment that is inclined relative to the flagellar axis. This scenario leads to intriguing double helical trajectories that we characterize as functions of the magnetic moment inclination and the magnetic field. For small inclination angles ([Formula: see text]) and typical field strengths, the inclination of the magnetic moment has only a minor effect on the swimming of MTB in an external magnetic field. Large inclination angles result in a strong reduction in the velocity in direction of the magnetic field, consistent with recent observations that bacteria with large inclination angles use a different propulsion mechanism.
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Affiliation(s)
- Sarah Mohammadinejad
- Institute for the Dynamics of Complex Systems, University of Göttingen, Friedrich-Hund-Platz 1, 37077, Göttingen, Germany.
- Department Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, 14424, Potsdam, Germany.
- Department of Biological Sciences, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, 45137-66731, Iran.
| | - Damien Faivre
- Department of Biomaterials, Max Planck Institute of Colloids and Interfaces, 14424, Potsdam, Germany
- Aix-Marseille Université, CEA, CNRS, BIAM, 13108, Saint-Paul-lez-Durance, France
| | - Stefan Klumpp
- Institute for the Dynamics of Complex Systems, University of Göttingen, Friedrich-Hund-Platz 1, 37077, Göttingen, Germany
- Department Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, 14424, Potsdam, Germany
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27
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Cambré A, Aertsen A. Bacterial Vivisection: How Fluorescence-Based Imaging Techniques Shed a Light on the Inner Workings of Bacteria. Microbiol Mol Biol Rev 2020; 84:e00008-20. [PMID: 33115939 PMCID: PMC7599038 DOI: 10.1128/mmbr.00008-20] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The rise in fluorescence-based imaging techniques over the past 3 decades has improved the ability of researchers to scrutinize live cell biology at increased spatial and temporal resolution. In microbiology, these real-time vivisections structurally changed the view on the bacterial cell away from the "watery bag of enzymes" paradigm toward the perspective that these organisms are as complex as their eukaryotic counterparts. Capitalizing on the enormous potential of (time-lapse) fluorescence microscopy and the ever-extending pallet of corresponding probes, initial breakthroughs were made in unraveling the localization of proteins and monitoring real-time gene expression. However, later it became clear that the potential of this technique extends much further, paving the way for a focus-shift from observing single events within bacterial cells or populations to obtaining a more global picture at the intra- and intercellular level. In this review, we outline the current state of the art in fluorescence-based vivisection of bacteria and provide an overview of important case studies to exemplify how to use or combine different strategies to gain detailed information on the cell's physiology. The manuscript therefore consists of two separate (but interconnected) parts that can be read and consulted individually. The first part focuses on the fluorescent probe pallet and provides a perspective on modern methodologies for microscopy using these tools. The second section of the review takes the reader on a tour through the bacterial cell from cytoplasm to outer shell, describing strategies and methods to highlight architectural features and overall dynamics within cells.
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Affiliation(s)
- Alexander Cambré
- KU Leuven, Department of Microbial and Molecular Systems, Faculty of Bioscience Engineering, Leuven, Belgium
| | - Abram Aertsen
- KU Leuven, Department of Microbial and Molecular Systems, Faculty of Bioscience Engineering, Leuven, Belgium
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28
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Stricker L, Guido I, Breithaupt T, Mazza MG, Vollmer J. Hybrid sideways/longitudinal swimming in the monoflagellate Shewanella oneidensis: from aerotactic band to biofilm. J R Soc Interface 2020; 17:20200559. [PMID: 33109020 PMCID: PMC7653395 DOI: 10.1098/rsif.2020.0559] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 10/06/2020] [Indexed: 11/12/2022] Open
Abstract
Shewanella oneidensis MR-1 are facultative aerobic electroactive bacteria with an appealing potential for sustainable energy production and bioremediation. They gather around air sources, forming aerotactic bands and biofilms. Here, we experimentally follow the evolution of the band around an air bubble, and we find good agreement with the numerical solutions of the pertinent transport equations. Video microscopy reveals a transition between motile and non-motile MR-1 upon oxygen depletion, preventing further development of the biofilm. We discover that MR-1 can alternate between longitudinal fast and sideways slow swimming. The resulting bimodal velocity distributions change in response to different oxygen concentrations and gradients, supporting the biological functions of aerotaxis and confinement.
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Affiliation(s)
- Laura Stricker
- ETH Zürich, Department of Materials, Polymer Physics, 8093 Zurich, Switzerland
| | - Isabella Guido
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), 37077 Göttingen, Germany
| | - Thomas Breithaupt
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), 37077 Göttingen, Germany
| | - Marco G. Mazza
- Max Planck Institute for Dynamics and Self-Organization (MPIDS), 37077 Göttingen, Germany
- Loughborough University, Interdisciplinary Centre for Mathematical Modelling and Department of Mathematical Sciences, Loughborough, Leicestershire LE11 3TU, UK
| | - Jürgen Vollmer
- University of Leipzig, Institute of Theoretical Physics, 04103 Leipzig, Germany
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Kinosita Y, Ishida T, Yoshida M, Ito R, Morimoto YV, Goto K, Berry RM, Nishizaka T, Sowa Y. Distinct chemotactic behavior in the original Escherichia coli K-12 depending on forward-and-backward swimming, not on run-tumble movements. Sci Rep 2020; 10:15887. [PMID: 32985511 PMCID: PMC7522084 DOI: 10.1038/s41598-020-72429-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 08/27/2020] [Indexed: 11/21/2022] Open
Abstract
Most motile bacteria are propelled by rigid, helical, flagellar filaments and display distinct swimming patterns to explore their favorable environments. Escherichia coli cells have a reversible rotary motor at the base of each filament. They exhibit a run-tumble swimming pattern, driven by switching of the rotational direction, which causes polymorphic flagellar transformation. Here we report a novel swimming mode in E. coli ATCC10798, which is one of the original K-12 clones. High-speed tracking of single ATCC10798 cells showed forward and backward swimming with an average turning angle of 150°. The flagellar helicity remained right-handed with a 1.3 μm pitch and 0.14 μm helix radius, which is consistent with the feature of a curly type, regardless of motor switching; the flagella of ATCC10798 did not show polymorphic transformation. The torque and rotational switching of the motor was almost identical to the E. coli W3110 strain, which is a derivative of K-12 and a wild-type for chemotaxis. The single point mutation of N87K in FliC, one of the filament subunits, is critical to the change in flagellar morphology and swimming pattern, and lack of flagellar polymorphism. E. coli cells expressing FliC(N87K) sensed ascending a chemotactic gradient in liquid but did not spread on a semi-solid surface. Based on these results, we concluded that a flagellar polymorphism is essential for spreading in structured environments.
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Affiliation(s)
- Yoshiaki Kinosita
- Department of Physics, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo, 171-8588, Japan.
- Department of Physics, University of Oxford, Park load, Oxford, OX1 3PU, UK.
- Molecular Physiology Laboratory, RIKEN, Wako, Japan.
| | - Tsubasa Ishida
- Department of Frontier Bioscience and Research Center for Micro-Nano Technology, Hosei University, Tokyo, 184-8584, Japan
| | - Myu Yoshida
- Department of Frontier Bioscience and Research Center for Micro-Nano Technology, Hosei University, Tokyo, 184-8584, Japan
| | - Rie Ito
- Department of Frontier Bioscience and Research Center for Micro-Nano Technology, Hosei University, Tokyo, 184-8584, Japan
| | - Yusuke V Morimoto
- Department of Physics and Information Technology, Faculty of Computer Science and Systems Engineering, Kyushu Institute of Technology, Iizuka, Fukuoka, Japan
| | - Kazuki Goto
- Department of Physics, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo, 171-8588, Japan
| | - Richard M Berry
- Department of Physics, University of Oxford, Park load, Oxford, OX1 3PU, UK
| | - Takayuki Nishizaka
- Department of Physics, Gakushuin University, 1-5-1 Mejiro, Toshima-ku, Tokyo, 171-8588, Japan
| | - Yoshiyuki Sowa
- Department of Frontier Bioscience and Research Center for Micro-Nano Technology, Hosei University, Tokyo, 184-8584, Japan.
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An ATP-dependent partner switch links flagellar C-ring assembly with gene expression. Proc Natl Acad Sci U S A 2020; 117:20826-20835. [PMID: 32788349 DOI: 10.1073/pnas.2006470117] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Bacterial flagella differ in their number and spatial arrangement. In many species, the MinD-type ATPase FlhG (also YlxH/FleN) is central to the numerical control of bacterial flagella, and its deletion in polarly flagellated bacteria typically leads to hyperflagellation. The molecular mechanism underlying this numerical control, however, remains enigmatic. Using the model species Shewanella putrefaciens, we show that FlhG links assembly of the flagellar C ring with the action of the master transcriptional regulator FlrA (named FleQ in other species). While FlrA and the flagellar C-ring protein FliM have an overlapping binding site on FlhG, their binding depends on the ATP-dependent dimerization state of FlhG. FliM interacts with FlhG independent of nucleotide binding, while FlrA exclusively interacts with the ATP-dependent FlhG dimer and stimulates FlhG ATPase activity. Our in vivo analysis of FlhG partner switching between FliM and FlrA reveals its mechanism in the numerical restriction of flagella, in which the transcriptional activity of FlrA is down-regulated through a negative feedback loop. Our study demonstrates another level of regulatory complexity underlying the spationumerical regulation of flagellar biogenesis and implies that flagellar assembly transcriptionally regulates the production of more initial building blocks.
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31
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Yang T, Sprinkle B, Guo Y, Qian J, Hua D, Donev A, Marr DWM, Wu N. Reconfigurable microbots folded from simple colloidal chains. Proc Natl Acad Sci U S A 2020; 117:18186-18193. [PMID: 32680965 PMCID: PMC7414297 DOI: 10.1073/pnas.2007255117] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
To overcome the reversible nature of low-Reynolds-number flow, a variety of biomimetic microrobotic propulsion schemes and devices capable of rapid transport have been developed. However, these approaches have been typically optimized for a specific function or environment and do not have the flexibility that many real organisms exhibit to thrive in complex microenvironments. Here, inspired by adaptable microbes and using a combination of experiment and simulation, we demonstrate that one-dimensional colloidal chains can fold into geometrically complex morphologies, including helices, plectonemes, lassos, and coils, and translate via multiple mechanisms that can be varied with applied magnetic field. With chains of multiblock asymmetry, the propulsion mode can be switched from bulk to surface-enabled, mimicking the swimming of microorganisms such as flagella-rotating bacteria and tail-whipping sperm and the surface-enabled motion of arching and stretching inchworms and sidewinding snakes. We also demonstrate that reconfigurability enables navigation through three-dimensional and narrow channels simulating capillary blood vessels. Our results show that flexible microdevices based on simple chains can transform both shape and motility under varying magnetic fields, a capability we expect will be particularly beneficial in complex in vivo microenvironments.
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Affiliation(s)
- Tao Yang
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, CO 80401
| | - Brennan Sprinkle
- Courant Institute of Mathematical Sciences, New York University, New York, NY 10012
| | - Yang Guo
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, CO 80401
| | - Jun Qian
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences, Soochow University, 215123 Suzhou, China
| | - Daoben Hua
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences, Soochow University, 215123 Suzhou, China
| | - Aleksandar Donev
- Courant Institute of Mathematical Sciences, New York University, New York, NY 10012
| | - David W M Marr
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, CO 80401;
| | - Ning Wu
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, CO 80401;
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32
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Cohen EJ, Nakane D, Kabata Y, Hendrixson DR, Nishizaka T, Beeby M. Campylobacter jejuni motility integrates specialized cell shape, flagellar filament, and motor, to coordinate action of its opposed flagella. PLoS Pathog 2020; 16:e1008620. [PMID: 32614919 PMCID: PMC7332011 DOI: 10.1371/journal.ppat.1008620] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 05/11/2020] [Indexed: 02/07/2023] Open
Abstract
Campylobacter jejuni rotates a flagellum at each pole to swim through the viscous mucosa of its hosts’ gastrointestinal tracts. Despite their importance for host colonization, however, how C. jejuni coordinates rotation of these two opposing flagella is unclear. As well as their polar placement, C. jejuni’s flagella deviate from the norm of Enterobacteriaceae in other ways: their flagellar motors produce much higher torque and their flagellar filament is made of two different zones of two different flagellins. To understand how C. jejuni’s opposed motors coordinate, and what contribution these factors play in C. jejuni motility, we developed strains with flagella that could be fluorescently labeled, and observed them by high-speed video microscopy. We found that C. jejuni coordinates its dual flagella by wrapping the leading filament around the cell body during swimming in high-viscosity media and that its differentiated flagellar filament and helical body have evolved to facilitate this wrapped-mode swimming. Campylobacter jejuni is a leading cause of gastroenteritis worldwide. This species uses its helical body and opposing flagella to drill its way through the viscous mucosa of host organisms’ gastrointestinal tracts. In this work, we show that C. jejuni coordinates its two opposing flagella by wrapping the leading flagellum around the cell body when swimming in viscous environments. We also provide evidence that the helical cell body of C. jejuni and its composite flagellar filament are important for wrapping and unwrapping of the flagellar filament during reversals of swimming direction.
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Affiliation(s)
- Eli J. Cohen
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Daisuke Nakane
- Department of Physics, Gakushuin University, Tokyo, Japan
| | - Yoshiki Kabata
- Department of Physics, Gakushuin University, Tokyo, Japan
| | - David R. Hendrixson
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | | | - Morgan Beeby
- Department of Life Sciences, Imperial College London, London, United Kingdom
- * E-mail:
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33
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Deng J, Molaei M, Chisholm NG, Stebe KJ. Motile Bacteria at Oil-Water Interfaces: Pseudomonas aeruginosa. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:6888-6902. [PMID: 32097012 DOI: 10.1021/acs.langmuir.9b03578] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Bacteria are important examples of active or self-propelled colloids. Because of their directed motion, they accumulate near interfaces. There, they can become trapped and swim adjacent to the interface via hydrodynamic interactions, or they can adsorb directly and swim in an adhered state with complex trajectories that differ from those in bulk in both form and spatiotemporal implications. We have adopted the monotrichous bacterium Pseudomonas aeruginosa PA01 as a model species and have studied its motion at oil-aqueous interfaces. We have identified conditions in which bacteria swim persistently without restructuring the interface, allowing detailed and prolonged study of their motion. In addition to characterizing the ensemble behavior of the bacteria, we have observed a gallery of distinct trajectories of individual swimmers on and near fluid interfaces. We attribute these diverse swimming behaviors to differing trapped states for the bacteria in the fluid interface. These trajectory types include Brownian diffusive paths for passive adsorbed bacteria, curvilinear trajectories including curly paths with radii of curvature larger than the cell body length, and rapid pirouette motions with radii of curvature comparable to the cell body length. Finally, we see interfacial visitors that come and go from the interfacial plane. We characterize these individual swimmer motions. This work may impact nutrient cycles for bacteria on or near interfaces in nature. This work will also have implications in microrobotics, as active colloids in general and bacteria in particular are used to carry cargo in this burgeoning field. Finally, these results have implications in engineering of active surfaces that exploit interfacially trapped self-propelled colloids.
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Affiliation(s)
- Jiayi Deng
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, United States
| | - Mehdi Molaei
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, United States
| | - Nicholas G Chisholm
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, United States
| | - Kathleen J Stebe
- Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, United States
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34
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Wu Z, He R, Zhang R, Yuan J. Swarming Motility Without Flagellar Motor Switching by Reversal of Swimming Direction in E. coli. Front Microbiol 2020; 11:1042. [PMID: 32670212 PMCID: PMC7326100 DOI: 10.3389/fmicb.2020.01042] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 04/27/2020] [Indexed: 01/08/2023] Open
Abstract
In a crowded environment such as a bacterial swarm, cells frequently got jammed and came to a stop, but were able to escape the traps by backing up in their moving course with a head-to-tail change (a reversal). Reversals are essential for the expansion of a bacterial swarm. Reversal for a wildtype cell usually involved polymorphic transformation of the flagellar filaments induced by directional switching of the flagellar motors. Here we discovered a new way of reversal in cells without motor switching and characterized its mechanisms. We further found that this type of reversal was not limited to swarmer cells, but also occurred for cells grown in a bulk solution. Therefore, reversal was a general way of escaping when cells got jammed in their natural complex habitats. The new way of reversal we discovered here offered a general strategy for cells to escape traps and explore their environment.
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Affiliation(s)
- Zhengyu Wu
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, University of Science and Technology of China, Hefei, China
| | - Rui He
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, University of Science and Technology of China, Hefei, China
| | - Rongjing Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, University of Science and Technology of China, Hefei, China
| | - Junhua Yuan
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, University of Science and Technology of China, Hefei, China
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35
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36
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Alirezaeizanjani Z, Großmann R, Pfeifer V, Hintsche M, Beta C. Chemotaxis strategies of bacteria with multiple run modes. SCIENCE ADVANCES 2020; 6:eaaz6153. [PMID: 32766440 PMCID: PMC7385427 DOI: 10.1126/sciadv.aaz6153] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 03/20/2020] [Indexed: 06/11/2023]
Abstract
Bacterial chemotaxis-a fundamental example of directional navigation in the living world-is key to many biological processes, including the spreading of bacterial infections. Many bacterial species were recently reported to exhibit several distinct swimming modes-the flagella may, for example, push the cell body or wrap around it. How do the different run modes shape the chemotaxis strategy of a multimode swimmer? Here, we investigate chemotactic motion of the soil bacterium Pseudomonas putida as a model organism. By simultaneously tracking the position of the cell body and the configuration of its flagella, we demonstrate that individual run modes show different chemotactic responses in nutrition gradients and, thus, constitute distinct behavioral states. On the basis of an active particle model, we demonstrate that switching between multiple run states that differ in their speed and responsiveness provides the basis for robust and efficient chemotaxis in complex natural habitats.
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Affiliation(s)
| | - Robert Großmann
- Institute of Physics and Astronomy, University of Potsdam, 14476 Potsdam, Germany
| | - Veronika Pfeifer
- Institute of Physics and Astronomy, University of Potsdam, 14476 Potsdam, Germany
| | - Marius Hintsche
- Institute of Physics and Astronomy, University of Potsdam, 14476 Potsdam, Germany
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37
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Toh W, Ang EYM, Ng TY, Lin R, Liu Z. Nanopumping of water via rotation of graphene nanoribbons. NANOTECHNOLOGY 2020; 31:175704. [PMID: 31931485 DOI: 10.1088/1361-6528/ab6ab6] [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
In this paper, we perform molecular dynamics simulations to propose a novel bio-inspired nanopumping mechanism that is achieved through the rotation of graphene nanoribbons. Due to the rotation and interaction with water, the graphene nanoribbons undergo morphological transformation. It is shown that with appropriate geometrical and spatial parameters, the resulting morphology is twisted ribbon, which is efficient in pumping of water through a channel. This mimics the propulsive behavior of bacterial flagella through continual rotation at the base and causing morphology of the geometry into twisted ribbons, thus driving flow. It was observed that the maximum flux rate decreases upon reaching the optimal configuration even with increasing rotational speed and graphene width. This is due to the development of cavitation near the region of the nanoribbon with tip velocities approaching the speed of sound in water. The simulation shows promising results where the flux rate of the driven flow outperforms various nanopump configurations that have been reported in recent literature by more than one order.
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Affiliation(s)
- William Toh
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
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38
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Hartmann R, Teeseling MCF, Thanbichler M, Drescher K. BacStalk: A comprehensive and interactive image analysis software tool for bacterial cell biology. Mol Microbiol 2020; 114:140-150. [DOI: 10.1111/mmi.14501] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 03/16/2020] [Indexed: 01/28/2023]
Affiliation(s)
- Raimo Hartmann
- Max Planck Institute for Terrestrial Microbiology Marburg Germany
| | | | - Martin Thanbichler
- Max Planck Institute for Terrestrial Microbiology Marburg Germany
- Department of Biology Philipps‐Universität Marburg Germany
- LOEWE Center for Synthetic Microbiology Marburg Germany
| | - Knut Drescher
- Max Planck Institute for Terrestrial Microbiology Marburg Germany
- LOEWE Center for Synthetic Microbiology Marburg Germany
- Department of Physics Philipps‐Universität Marburg Germany
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39
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Beeby M, Ferreira JL, Tripp P, Albers SV, Mitchell DR. Propulsive nanomachines: the convergent evolution of archaella, flagella and cilia. FEMS Microbiol Rev 2020; 44:253-304. [DOI: 10.1093/femsre/fuaa006] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 03/06/2020] [Indexed: 02/06/2023] Open
Abstract
ABSTRACT
Echoing the repeated convergent evolution of flight and vision in large eukaryotes, propulsive swimming motility has evolved independently in microbes in each of the three domains of life. Filamentous appendages – archaella in Archaea, flagella in Bacteria and cilia in Eukaryotes – wave, whip or rotate to propel microbes, overcoming diffusion and enabling colonization of new environments. The implementations of the three propulsive nanomachines are distinct, however: archaella and flagella rotate, while cilia beat or wave; flagella and cilia assemble at their tips, while archaella assemble at their base; archaella and cilia use ATP for motility, while flagella use ion-motive force. These underlying differences reflect the tinkering required to evolve a molecular machine, in which pre-existing machines in the appropriate contexts were iteratively co-opted for new functions and whose origins are reflected in their resultant mechanisms. Contemporary homologies suggest that archaella evolved from a non-rotary pilus, flagella from a non-rotary appendage or secretion system, and cilia from a passive sensory structure. Here, we review the structure, assembly, mechanism and homologies of the three distinct solutions as a foundation to better understand how propulsive nanomachines evolved three times independently and to highlight principles of molecular evolution.
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Affiliation(s)
- Morgan Beeby
- Department of Life Sciences, Frankland Road, Imperial College of London, London, SW7 2AZ, UK
| | - Josie L Ferreira
- Department of Life Sciences, Frankland Road, Imperial College of London, London, SW7 2AZ, UK
| | - Patrick Tripp
- Molecular Biology of Archaea, Institute of Biology, University of Freiburg, Schaenzlestrasse 1, 79211 Freiburg, Germany
| | - Sonja-Verena Albers
- Molecular Biology of Archaea, Institute of Biology, University of Freiburg, Schaenzlestrasse 1, 79211 Freiburg, Germany
| | - David R Mitchell
- Department of Cell and Developmental Biology, SUNY Upstate Medical University, 750 E. Adams St., Syracuse, NY 13210, USA
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Quantifying the Benefit of a Dedicated "Magnetoskeleton" in Bacterial Magnetotaxis by Live-Cell Motility Tracking and Soft Agar Swimming Assay. Appl Environ Microbiol 2020; 86:AEM.01976-19. [PMID: 31732570 DOI: 10.1128/aem.01976-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 11/08/2019] [Indexed: 12/20/2022] Open
Abstract
The alphaproteobacterium Magnetospirillum gryphiswaldense has the intriguing ability to navigate within magnetic fields, a behavior named magnetotaxis, governed by the formation of magnetosomes, intracellular membrane-enveloped crystals of magnetite. Magnetosomes are aligned in chains along the cell's motility axis by a dedicated multipart cytoskeleton ("magnetoskeleton"); however, precise estimates of its significance for magnetotaxis have not been reported. Here, we estimated the alignment of strains deficient in various magnetoskeletal constituents by live-cell motility tracking within defined magnetic fields ranging from 50 μT (reflecting the geomagnetic field) up to 400 μT. Motility tracking revealed that ΔmamY and ΔmamK strains (which assemble mispositioned and fragmented chains, respectively) are partially impaired in magnetotaxis, with approximately equal contributions of both proteins. This impairment was reflected by a required magnetic field strength of 200 μT to achieve a similar degree of alignment as for the wild-type strain in a 50-μT magnetic field. In contrast, the ΔmamJ strain, which predominantly forms clusters of magnetosomes, was only weakly aligned under any of the tested field conditions and could barely be distinguished from a nonmagnetic mutant. Most findings were corroborated by a soft agar swimming assay to analyze magnetotaxis based on the degree of distortion of swim halos formed in magnetic fields. Motility tracking further revealed that swimming speeds of M. gryphiswaldense are highest within the field strength equaling the geomagnetic field. In conclusion, magnetic properties and intracellular positioning of magnetosomes by a dedicated magnetoskeleton are required and optimized for bacterial magnetotaxis and most efficient locomotion within the geomagnetic field.IMPORTANCE In Magnetospirillum gryphiswaldense, magnetosomes are aligned in quasi-linear chains in a helical cell by a complex cytoskeletal network, including the actin-like MamK and adapter MamJ for magnetosome chain concatenation and segregation and MamY to position magnetosome chains along the shortest cellular axis of motility. Magnetosome chain positioning is assumed to be required for efficient magnetic navigation; however, the significance and contribution of all key constituents have not been quantified within defined and weak magnetic fields reflecting the geomagnetic field. Employing two different motility-based methods to consider the flagellum-mediated propulsion of cells, we depict individual benefits of all magnetoskeletal constituents for magnetotaxis. Whereas lack of mamJ resulted almost in an inability to align cells in weak magnetic fields, an approximately 4-fold-increased magnetic field strength was required to compensate for the loss of mamK or mamY In summary, the magnetoskeleton and optimal positioning of magnetosome chains are required for efficient magnetotaxis.
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41
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Mechanomicrobiology: how bacteria sense and respond to forces. Nat Rev Microbiol 2020; 18:227-240. [DOI: 10.1038/s41579-019-0314-2] [Citation(s) in RCA: 99] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/06/2019] [Indexed: 12/26/2022]
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Chae MK, Kim Y, Johner A, Lee NK. Adsorption of a Helical Filament Subject to Thermal Fluctuations. Polymers (Basel) 2020; 12:polym12010192. [PMID: 31936860 PMCID: PMC7023455 DOI: 10.3390/polym12010192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 01/02/2020] [Accepted: 01/05/2020] [Indexed: 02/06/2023] Open
Abstract
We consider semiflexible chains governed by preferred curvature and twist and their flexural and twist moduli. These filaments possess a helical rather than straight three-dimensional (3D) ground state and we call them helical filaments (H-filament). Depending on the moduli, the helical shape may be smeared by thermal fluctuations. Secondary superhelical structures are expected to form on top of the specific local structure of biofilaments, as is documented for vimentin. We study confinement and adsorption of helical filaments utilizing both a combination of numerical simulations and analytical theory. We investigate overall chain shapes, transverse chain fluctuations, loop and tail distributions, and energy distributions along the chain together with the mean square average height of the monomers 〈 z 2 〉 . The number fraction of adsorbed monomers serves as an order parameter for adsorption. Signatures of adsorbed helical polymers are the occurrence of 3D helical loops/tails and spiral or wavy quasi-flat shapes. None of these arise for the Worm-Like-Chain, whose straight ground state can be embedded in a plane.
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Affiliation(s)
- M.-K. Chae
- Department of Physics and Astronomy, Sejong University, Seoul 05006, Korea
| | - Y. Kim
- Department of Physics and Astronomy, Sejong University, Seoul 05006, Korea
| | - A. Johner
- Institute Charles Sadron, CNRS 23 Rue du Loess, 67034 Strasbourg CEDEX 2, France
- Correspondence: or (A.J.); (N.-K.L.)
| | - N.-K. Lee
- Department of Physics and Astronomy, Sejong University, Seoul 05006, Korea
- Institute Charles Sadron, CNRS 23 Rue du Loess, 67034 Strasbourg CEDEX 2, France
- Correspondence: or (A.J.); (N.-K.L.)
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43
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Abstract
Cells from all three domains of life on Earth utilize motile macromolecular devices that protrude from the cell surface to generate forces that allow them to swim through fluid media. Research carried out on archaea during the past decade or so has led to the recognition that, despite their common function, the motility devices of the three domains display fundamental differences in their properties and ancestry, reflecting a striking example of convergent evolution. Thus, the flagella of bacteria and the archaella of archaea employ rotary filaments that assemble from distinct subunits that do not share a common ancestor and generate torque using energy derived from distinct fuel sources, namely chemiosmotic ion gradients and FlaI motor-catalyzed ATP hydrolysis, respectively. The cilia of eukaryotes, however, assemble via kinesin-2-driven intraflagellar transport and utilize microtubules and ATP-hydrolyzing dynein motors to beat in a variety of waveforms via a sliding filament mechanism. Here, with reference to current structural and mechanistic information about these organelles, we briefly compare the evolutionary origins, assembly and tactic motility of archaella, flagella and cilia.
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Affiliation(s)
- Shahid Khan
- Molecular Biology Consortium, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
| | - Jonathan M Scholey
- Department of Molecular and Cell Biology, University of California @ Davis, CA 95616, USA.
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44
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Abstract
Mucus plays crucial roles in higher organisms, from aiding fertilization to protecting the female reproductive tract. Here, we investigate how anisotropic organization of mucus affects bacterial motility. We demonstrate by cryo electron micrographs and elongated tracer particles imaging, that mucus anisotropy and heterogeneity depend on how mechanical stress is applied. In shallow mucus films, we observe bacteria reversing their swimming direction without U-turns. During the forward motion, bacteria burrowed tunnels that last for several seconds and enable them to swim back faster, following the same track. We elucidate the physical mechanism of direction reversal by fluorescent visualization of the flagella: when the bacterial body is suddenly stopped by the mucus structure, the compression on the flagellar bundle causes buckling, disassembly and reorganization on the other side of the bacterium. Our results shed light into motility of bacteria in complex visco-elastic fluids and can provide clues in the propagation of bacteria-born diseases in mucus.
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Sathyamoorthy R, Maoz A, Pasternak Z, Im H, Huppert A, Kadouri D, Jurkevitch E. Bacterial predation under changing viscosities. Environ Microbiol 2019; 21:2997-3010. [DOI: 10.1111/1462-2920.14696] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Revised: 03/23/2019] [Accepted: 05/24/2019] [Indexed: 12/13/2022]
Affiliation(s)
- Rajesh Sathyamoorthy
- Department of Plant Pathology and Microbiology, Faculty of Agriculture, Food and Environment The Hebrew University of Jerusalem Rehovot Israel
| | - Anat Maoz
- Bio‐statistical Unit, The Gertner Institute for Epidemiology and Health Policy Research Chaim Sheba Medical Center Tel Hashomer Israel
| | - Zohar Pasternak
- Department of Plant Pathology and Microbiology, Faculty of Agriculture, Food and Environment The Hebrew University of Jerusalem Rehovot Israel
| | - Hansol Im
- School of Life Sciences Ulsan National Institute of Science & Technology 50 UNIST‐gil Ulju‐gun, Ulsan 44919 Republic of Korea
| | - Amit Huppert
- Bio‐statistical Unit, The Gertner Institute for Epidemiology and Health Policy Research Chaim Sheba Medical Center Tel Hashomer Israel
| | - Daniel Kadouri
- Department of Oral Biology Rutgers School of Dental Medicine Newark NJ USA
| | - Edouard Jurkevitch
- Department of Plant Pathology and Microbiology, Faculty of Agriculture, Food and Environment The Hebrew University of Jerusalem Rehovot Israel
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Lim S, Guo X, Boedicker JQ. Connecting single-cell properties to collective behavior in multiple wild isolates of the Enterobacter cloacae complex. PLoS One 2019; 14:e0214719. [PMID: 30947254 PMCID: PMC6448878 DOI: 10.1371/journal.pone.0214719] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 03/19/2019] [Indexed: 11/24/2022] Open
Abstract
Some strains of motile bacteria self-organize to form spatial patterns of high and low cell density over length scales that can be observed by eye. One such collective behavior is the formation in semisolid agar media of a high cell density swarm band. We isolated 7 wild strains of the Enterobacter cloacae complex capable of forming this band and found its propagation speed can vary 2.5 fold across strains. To connect such variability in collective motility to strain properties, each strain’s single-cell motility and exponential growth rates were measured. The band speed did not significantly correlate with any individual strain property; however, a multilinear analysis revealed that the band speed was set by a combination of the run speed and tumbling frequency. Comparison of variability in closely-related wild isolates has the potential to reveal how changes in single-cell properties influence the collective behavior of populations.
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Affiliation(s)
- Sean Lim
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California, United States of America
| | - Xiaokan Guo
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California, United States of America
| | - James Q. Boedicker
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California, United States of America
- Department of Biological Sciences, University of Southern California, Los Angeles, California, United States of America
- * E-mail:
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47
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Raina JB, Fernandez V, Lambert B, Stocker R, Seymour JR. The role of microbial motility and chemotaxis in symbiosis. Nat Rev Microbiol 2019; 17:284-294. [DOI: 10.1038/s41579-019-0182-9] [Citation(s) in RCA: 105] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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48
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Kaplan M, Ghosal D, Subramanian P, Oikonomou CM, Kjaer A, Pirbadian S, Ortega DR, Briegel A, El-Naggar MY, Jensen GJ. The presence and absence of periplasmic rings in bacterial flagellar motors correlates with stator type. eLife 2019; 8:43487. [PMID: 30648971 PMCID: PMC6375700 DOI: 10.7554/elife.43487] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 12/19/2018] [Indexed: 12/22/2022] Open
Abstract
The bacterial flagellar motor, a cell-envelope-embedded macromolecular machine that functions as a cellular propeller, exhibits significant structural variability between species. Different torque-generating stator modules allow motors to operate in different pH, salt or viscosity levels. How such diversity evolved is unknown. Here, we use electron cryo-tomography to determine the in situ macromolecular structures of three Gammaproteobacteria motors: Legionella pneumophila, Pseudomonas aeruginosa, and Shewanella oneidensis, providing the first views of intact motors with dual stator systems. Complementing our imaging with bioinformatics analysis, we find a correlation between the motor’s stator system and its structural elaboration. Motors with a single H+-driven stator have only the core periplasmic P- and L-rings; those with dual H+-driven stators have an elaborated P-ring; and motors with Na+ or Na+/H+-driven stators have both their P- and L-rings embellished. Our results suggest an evolution of structural elaboration that may have enabled pathogenic bacteria to colonize higher-viscosity environments in animal hosts. Bacteria are so small that for them, making their way through water is like swimming in roofing tar for us. In response, these organisms have evolved a molecular machine that helps them move in their environment. Named the bacterial flagellum, this complex assemblage of molecules is formed of three main parts: a motor that spans the inner and outer membranes of the cell, and then a ‘hook’ that connects to a long filament which extends outside the bacterium. More precisely, the motor is formed of the stator, an ion pump that stays still, and of a rotor that can spin. Different rings can also be present in the space between the inner and outer membranes (the periplasm) and surround these components. The stator uses ions to generate the energy that makes the rotor whirl. In turn, this movement sets the filament in motion, propelling the bacterium. Depending on where the bacteria live, the stator can use different types of ions. In addition, while many species have a single stator system per motor, some may have several stator systems for one motor: this may help the microorganisms move in different conditions. As microbes colonize environments with a different pH or viscosity, they constantly evolve new versions of the motor which are more suitable to their new surroundings. However, a part of the motor remains the same across species. Overall, it is still unclear how bacterial flagella evolve, but examining the structure of new motors can shed light upon this process. Here, Kaplan et al. combine a bioinformatics approach with an imaging technique known as electron cryo-tomography to dissect the structure of the flagellar motor of three species of bacteria with different stator systems, and compare these to known motors of the same class. The results reveal a correlation between the nature of the stator system and the presence of certain elements. Stators that use sodium ions, or both sodium and hydrogen ions, are associated with two periplasmic rings surrounding the conserved motor structure. These rings do not exist in motors with single hydrogen-driven stators. Motors with dual hydrogen-driven stators are, to some extent, an ‘intermediate state’, with only one of those rings present. As all the studied species currently exist, it is difficult to know which version of the motor is the most ancient, and which one has evolved more recently. Capturing the diversity of bacterial motors gives us insight into the evolutionary forces that shape complex molecular structures, which is essential to understand how life evolved on Earth. More practically, this knowledge may also help us design better nanomachines to power microscopic robots.
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Affiliation(s)
- Mohammed Kaplan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Debnath Ghosal
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Poorna Subramanian
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Catherine M Oikonomou
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Andreas Kjaer
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Sahand Pirbadian
- Department of Physics and Astronomy, Biological Sciences, and Chemistry, University of Southern California, Los Angeles, United States
| | - Davi R Ortega
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Ariane Briegel
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Mohamed Y El-Naggar
- Department of Physics and Astronomy, Biological Sciences, and Chemistry, University of Southern California, Los Angeles, United States
| | - Grant J Jensen
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States.,Howard Hughes Medical Institute, California Institute of Technology, Pasadena, United States
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49
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Huang HW, Uslu FE, Katsamba P, Lauga E, Sakar MS, Nelson BJ. Adaptive locomotion of artificial microswimmers. SCIENCE ADVANCES 2019; 5:eaau1532. [PMID: 30746446 PMCID: PMC6357760 DOI: 10.1126/sciadv.aau1532] [Citation(s) in RCA: 115] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 12/04/2018] [Indexed: 05/06/2023]
Abstract
Bacteria can exploit mechanics to display remarkable plasticity in response to locally changing physical and chemical conditions. Compliant structures play a notable role in their taxis behavior, specifically for navigation inside complex and structured environments. Bioinspired mechanisms with rationally designed architectures capable of large, nonlinear deformation present opportunities for introducing autonomy into engineered small-scale devices. This work analyzes the effect of hydrodynamic forces and rheology of local surroundings on swimming at low Reynolds number, identifies the challenges and benefits of using elastohydrodynamic coupling in locomotion, and further develops a suite of machinery for building untethered microrobots with self-regulated mobility. We demonstrate that coupling the structural and magnetic properties of artificial microswimmers with the dynamic properties of the fluid leads to adaptive locomotion in the absence of on-board sensors.
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Affiliation(s)
- H.-W. Huang
- Department of Mechanical Engineering, ETH Zurich, CH-8092 Zurich, Switzerland
| | - F. E. Uslu
- Institute of Mechanical Engineering, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - P. Katsamba
- Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge CB3 0WA, UK
| | - E. Lauga
- Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge CB3 0WA, UK
| | - M. S. Sakar
- Institute of Mechanical Engineering, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
| | - B. J. Nelson
- Department of Mechanical Engineering, ETH Zurich, CH-8092 Zurich, Switzerland
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50
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Kühn MJ, Schmidt FK, Farthing NE, Rossmann FM, Helm B, Wilson LG, Eckhardt B, Thormann KM. Spatial arrangement of several flagellins within bacterial flagella improves motility in different environments. Nat Commun 2018; 9:5369. [PMID: 30560868 PMCID: PMC6299084 DOI: 10.1038/s41467-018-07802-w] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 11/22/2018] [Indexed: 11/26/2022] Open
Abstract
Bacterial flagella are helical proteinaceous fibers, composed of the protein flagellin, that confer motility to many bacterial species. The genomes of about half of all flagellated species include more than one flagellin gene, for reasons mostly unknown. Here we show that two flagellins (FlaA and FlaB) are spatially arranged in the polar flagellum of Shewanella putrefaciens, with FlaA being more abundant close to the motor and FlaB in the remainder of the flagellar filament. Observations of swimming trajectories and numerical simulations demonstrate that this segmentation improves motility in a range of environmental conditions, compared to mutants with single-flagellin filaments. In particular, it facilitates screw-like motility, which enhances cellular spreading through obstructed environments. Similar mechanisms may apply to other bacterial species and may explain the maintenance of multiple flagellins to form the flagellar filament.
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Affiliation(s)
- Marco J Kühn
- Institut für Mikrobiologie und Molekularbiologie, Justus-Liebig-Universität Gießen, 35392, Gießen, Germany
| | - Felix K Schmidt
- Fachbereich Physik und LOEWE Zentrum für Synthetische Mikrobiologie, Philipps-Universität Marburg, 35032, Marburg, Germany
| | - Nicola E Farthing
- Department of Physics, University of York, Heslington, York, YO10 5DD, UK
- Department of Mathematics, University of York, Heslington, York, YO10 5DD, UK
| | - Florian M Rossmann
- Institut für Mikrobiologie und Molekularbiologie, Justus-Liebig-Universität Gießen, 35392, Gießen, Germany
| | - Bina Helm
- Institut für Mikrobiologie und Molekularbiologie, Justus-Liebig-Universität Gießen, 35392, Gießen, Germany
| | - Laurence G Wilson
- Department of Physics, University of York, Heslington, York, YO10 5DD, UK.
| | - Bruno Eckhardt
- Fachbereich Physik und LOEWE Zentrum für Synthetische Mikrobiologie, Philipps-Universität Marburg, 35032, Marburg, Germany.
| | - Kai M Thormann
- Institut für Mikrobiologie und Molekularbiologie, Justus-Liebig-Universität Gießen, 35392, Gießen, Germany.
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