1
|
Luz R, Cordeiro R, Gonçalves V, Vasconcelos V, Urbatzka R. Screening of Lipid-Reducing Activity and Cytotoxicity of the Exometabolome from Cyanobacteria. Mar Drugs 2024; 22:412. [PMID: 39330293 PMCID: PMC11433081 DOI: 10.3390/md22090412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2024] [Revised: 09/03/2024] [Accepted: 09/06/2024] [Indexed: 09/28/2024] Open
Abstract
Cyanobacteria are rich producers of secondary metabolites, excreting some of these to the culture media. However, the exometabolome of cyanobacteria has been poorly studied, and few studies have dwelled on its characterization and bioactivity assessment. In this work, exometabolomes of 56 cyanobacterial strains were characterized by HR-ESI-LC-MS/MS. Cytotoxicity was assessed on two carcinoma cell lines, HepG2 and HCT116, while the reduction in lipids was tested in zebrafish larvae and in a steatosis model with fatty acid-overloaded human liver cells. The exometabolome analysis using GNPS revealed many complex clusters of unique compounds in several strains, with no identifications in public databases. Three strains reduced viability in HCT116 cells, namely Tolypotrichaceae BACA0428 (30.45%), Aphanizomenonaceae BACA0025 (40.84%), and Microchaetaceae BACA0110 (46.61%). Lipid reduction in zebrafish larvae was only observed by exposure to Dulcicalothrix sp. BACA0344 (60%). The feature-based molecular network shows that this bioactivity was highly correlated with two flavanones, a compound class described in the literature to have lipid reduction activity. The exometabolome characterization of cyanobacteria strains revealed a high chemodiversity, which supports it as a source for novel bioactive compounds, despite most of the time being overlooked.
Collapse
Affiliation(s)
- Rúben Luz
- Faculdade de Ciências e Tecnologia, Universidade dos Açores, 9500-321 Ponta Delgada, Portugal
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, BIOPOLIS Program in Genomics, Biodiversity and Land Planning; UNESCO Chair-Land Within Sea: Biodiversity & Sustainability in Atlantic Islands, Universidade dos Açores, 9500-321 Ponta Delgada, Portugal
| | - Rita Cordeiro
- Faculdade de Ciências e Tecnologia, Universidade dos Açores, 9500-321 Ponta Delgada, Portugal
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, BIOPOLIS Program in Genomics, Biodiversity and Land Planning; UNESCO Chair-Land Within Sea: Biodiversity & Sustainability in Atlantic Islands, Universidade dos Açores, 9500-321 Ponta Delgada, Portugal
| | - Vítor Gonçalves
- Faculdade de Ciências e Tecnologia, Universidade dos Açores, 9500-321 Ponta Delgada, Portugal
- CIBIO, Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO Laboratório Associado, BIOPOLIS Program in Genomics, Biodiversity and Land Planning; UNESCO Chair-Land Within Sea: Biodiversity & Sustainability in Atlantic Islands, Universidade dos Açores, 9500-321 Ponta Delgada, Portugal
| | - Vitor Vasconcelos
- Interdisciplinary Centre of Marine and Environmental Research-CIIMAR/CIMAR, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal
- Department of Biology, Faculty of Sciences, University of Porto, 4069-007 Porto, Portugal
| | - Ralph Urbatzka
- Interdisciplinary Centre of Marine and Environmental Research-CIIMAR/CIMAR, University of Porto, Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal
| |
Collapse
|
2
|
Janović A, Maldener I, Menzel C, Parrett GA, Risser DD. The role of FraI in cell-cell communication and differentiation in the hormogonia-forming cyanobacterium Nostoc punctiforme. mSphere 2024; 9:e0051024. [PMID: 39037261 PMCID: PMC11351039 DOI: 10.1128/msphere.00510-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2024] [Accepted: 06/21/2024] [Indexed: 07/23/2024] Open
Abstract
Multicellular cyanobacteria, like Nostoc punctiforme, rely on septal junctions for cell-cell communication, which is crucial for coordinating various physiological processes including differentiation of N2-fixing heterocysts, spore-like akinetes, and hormogonia-short, motile filaments important for dispersal. In this study, we functionally characterize a protein, encoded by gene Npun_F4142, which in a random mutagenesis approach, initially showed a motility-related function. The reconstructed Npun_F4142 knockout mutant exhibits further distinct phenotypic traits, including altered hormogonia formation with significant reduced motility, inability to differentiate heterocysts and filament fragmentation. For that reason, we named the protein FraI (fragmentation phenotype). The mutant displays severely impaired cell-cell communication, due to almost complete absence of the nanopore array in the septal cell wall, which is an essential part of the septal junctions. Despite lack of communication, hormogonia in the ΔfraI mutant maintain motility and phototactic behavior, even though less pronounced than the wild type (WT). This suggests an alternative mechanism for coordinated movement beyond septal junctions. Our study underscores the significance of FraI in nanopore formation and cell differentiation, and provides additional evidence for the importance of septal junction formation and communication in various differentiation traits of cyanobacteria. The findings contribute to a deeper understanding of the regulatory networks governing multicellular cyanobacterial behavior, with implications for broader insights into microbial multicellularity. IMPORTANCE The filament-forming cyanobacterium Nostoc punctiforme serves as a valuable model for studying cell differentiation, including the formation of nitrogen-fixing heterocysts and hormogonia. Hormogonia filaments play a crucial role in dispersal and plant colonization, providing a nitrogen source through atmospheric nitrogen fixation, thus holding promise for fertilizer-free agriculture. The coordination among the hormogonia cells enabling uniform movement toward the positive signal remains poorly understood. This study investigates the role of septal junction-mediated communication in hormogonia differentiation and motility, by studying a ΔfraI mutant with significantly impaired communication. Surprisingly, impaired communication does not abolish synchronized filament movement, suggesting an alternative coordination mechanism. These findings deepen our understanding of cyanobacterial biology and have broader implications for multicellular behavior in prokaryotes.
Collapse
Affiliation(s)
- Ana Janović
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Organismic Interactions, University of Tübingen, Tübingen, Germany
| | - Iris Maldener
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Organismic Interactions, University of Tübingen, Tübingen, Germany
| | - Claudia Menzel
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen, Organismic Interactions, University of Tübingen, Tübingen, Germany
| | - Gabriel A. Parrett
- Department of Biology, University of Colorado, Colorado Springs, Colorado, USA
| | - Douglas D. Risser
- Department of Biology, University of Colorado, Colorado Springs, Colorado, USA
| |
Collapse
|
3
|
Beaud Benyahia B, Taib N, Beloin C, Gribaldo S. Terrabacteria: redefining bacterial envelope diversity, biogenesis and evolution. Nat Rev Microbiol 2024:10.1038/s41579-024-01088-0. [PMID: 39198708 DOI: 10.1038/s41579-024-01088-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/12/2024] [Indexed: 09/01/2024]
Abstract
The bacterial envelope is one of the oldest and most essential cellular components and has been traditionally divided into Gram-positive (monoderm) and Gram-negative (diderm). Recent landmark studies have challenged a major paradigm in microbiology by inferring that the last bacterial common ancestor had a diderm envelope and that the outer membrane (OM) was lost repeatedly in evolution to give rise to monoderms. Intriguingly, OM losses appear to have occurred exclusively in the Terrabacteria, one of the two major clades of bacteria. In this Review, we present current knowledge about the Terrabacteria. We describe their diversity and phylogeny and then highlight the vast phenotypic diversity of the Terrabacteria cell envelopes, which display large deviations from the textbook examples of diderms and monoderms, challenging the classical Gram-positive-Gram-negative divide. We highlight the striking differences in the systems involved in OM biogenesis in Terrabacteria with respect to the classical diderm experimental models and how they provide novel insights into the diversity and biogenesis of the bacterial cell envelope. We also discuss the potential evolutionary steps that might have led to the multiple losses of the OM and speculate on how the very first OM might have emerged before the last bacterial common ancestor.
Collapse
Affiliation(s)
- Basile Beaud Benyahia
- Evolutionary Biology of the Microbial Cell Laboratory, Institut Pasteur, Université Paris Cité, Paris, France
| | - Najwa Taib
- Evolutionary Biology of the Microbial Cell Laboratory, Institut Pasteur, Université Paris Cité, Paris, France
- Bioinformatics and Biostatistics Hub, Institut Pasteur, Université Paris Cité, Paris, France
| | - Christophe Beloin
- Genetics of Biofilms Laboratory, Institut Pasteur, Université Paris Cité, Paris, France
| | - Simonetta Gribaldo
- Evolutionary Biology of the Microbial Cell Laboratory, Institut Pasteur, Université Paris Cité, Paris, France.
| |
Collapse
|
4
|
Kurjahn M, Deka A, Girot A, Abbaspour L, Klumpp S, Lorenz M, Bäumchen O, Karpitschka S. Quantifying gliding forces of filamentous cyanobacteria by self-buckling. eLife 2024; 12:RP87450. [PMID: 38864737 PMCID: PMC11178357 DOI: 10.7554/elife.87450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2024] Open
Abstract
Filamentous cyanobacteria are one of the oldest and today still most abundant lifeforms on earth, with manifold implications in ecology and economics. Their flexible filaments, often several hundred cells long, exhibit gliding motility in contact with solid surfaces. The underlying force generating mechanism is not yet understood. Here, we demonstrate that propulsion forces and friction coefficients are strongly coupled in the gliding motility of filamentous cyanobacteria. We directly measure their bending moduli using micropipette force sensors, and quantify propulsion and friction forces by analyzing their self-buckling behavior, complemented with analytical theory and simulations. The results indicate that slime extrusion unlikely generates the gliding forces, but support adhesion-based hypotheses, similar to the better-studied single-celled myxobacteria. The critical self-buckling lengths align well with the peaks of natural length distributions, indicating the importance of self-buckling for the organization of their collective in natural and artificial settings.
Collapse
Affiliation(s)
- Maximilian Kurjahn
- Max Planck Institute for Dynamics and Self-Organization (MPI-DS)GöttingenGermany
| | - Antaran Deka
- Max Planck Institute for Dynamics and Self-Organization (MPI-DS)GöttingenGermany
| | - Antoine Girot
- Max Planck Institute for Dynamics and Self-Organization (MPI-DS)GöttingenGermany
- Experimental Physics V, University of BayreuthBayreuthGermany
| | - Leila Abbaspour
- Max Planck School Matter to Life, University of GöttingenGöttingenGermany
- Institute for Dynamics of Complex Systems, University of GöttingenGöttingenGermany
| | - Stefan Klumpp
- Max Planck School Matter to Life, University of GöttingenGöttingenGermany
- Institute for Dynamics of Complex Systems, University of GöttingenGöttingenGermany
| | - Maike Lorenz
- Department of Experimental Phycology and SAG Culture Collection of Algae Albrecht-von-Haller Institute for Plant Science, University of GöttingenGöttingenGermany
| | - Oliver Bäumchen
- Max Planck Institute for Dynamics and Self-Organization (MPI-DS)GöttingenGermany
- Experimental Physics V, University of BayreuthBayreuthGermany
| | - Stefan Karpitschka
- Max Planck Institute for Dynamics and Self-Organization (MPI-DS)GöttingenGermany
- Fachbereich Physik, University of KonstanzKonstanzGermany
| |
Collapse
|
5
|
An X, Zhong D, Wu W, Wang R, Yang L, Jiang Q, Zhou M, Xu X. Doxorubicin-Loaded Microalgal Delivery System for Combined Chemotherapy and Enhanced Photodynamic Therapy of Osteosarcoma. ACS APPLIED MATERIALS & INTERFACES 2024; 16:6868-6878. [PMID: 38294964 DOI: 10.1021/acsami.3c16995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2024]
Abstract
Osteosarcoma (OS) is considered the most frequent type of primary malignant bone tumor. Currently, radiotherapy, photodynamic (PDT), and other therapies for osteosarcoma are limited by tumor hypoxia and single efficacy and serve side-effects. Herein, we reported a microalgal drug delivery system (SpiD), doxorubicin (DOX)-loaded Spirulina platensis (Spi) for OS therapy. The specific surface of Spirulina platensis allowed for effective loading of DOX via surface channels and electrostatic interactions. Under 650 nm laser irradiation, SpiD enabled high oxygen production by photosynthesis and enhanced reactive oxygen species (ROS) generation via chlorophyll-assisted photosensitization, synergistically killing tumor cells with the released DOX. Combined chemotherapy and enhanced PDT mediated by SpiD exerted synergic antitumor effects and resulted in potent therapeutic efficacy in orthotopic osteosarcoma mice. Furthermore, SpiD could reduce the side-effects of chemotherapy, showing excellent blood and tissue safety. Taken together, this microalgal drug delivery system provided a natural, efficient, safe, and inexpensive strategy for OS treatment.
Collapse
Affiliation(s)
- Xueying An
- State Key Laboratory of Pharmaceutical Biotechnology, Division of Sports Medicine and Adult Reconstructive Surgery, Department of Orthopedic Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing 210093, China
| | - Danni Zhong
- Eye Center, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
- Institute of Translational Medicine, Zhejiang University, Hangzhou 310058, China
| | - Wenshu Wu
- State Key Laboratory of Pharmaceutical Biotechnology, Division of Sports Medicine and Adult Reconstructive Surgery, Department of Orthopedic Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing 210093, China
| | - Ruoxi Wang
- Institute of Translational Medicine, Zhejiang University, Hangzhou 310058, China
| | - Lin Yang
- State Key Laboratory of Pharmaceutical Biotechnology, Division of Sports Medicine and Adult Reconstructive Surgery, Department of Orthopedic Surgery, Nanjing Drum Tower Hospital, Clinical College of Nanjing Medical University, Nanjing 210093, China
| | - Qing Jiang
- State Key Laboratory of Pharmaceutical Biotechnology, Division of Sports Medicine and Adult Reconstructive Surgery, Department of Orthopedic Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing 210093, China
- Branch of National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, Nanjing 210008, China
| | - Min Zhou
- Eye Center, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
- State Key Laboratory of Modern Optical Instrumentations, Zhejiang University, Hangzhou 310058, China
- Zhejiang University-University of Edinburgh Institute (ZJU-UoE Institute), Zhejiang University School of Medicine, Haining 314400, China
| | - Xingquan Xu
- State Key Laboratory of Pharmaceutical Biotechnology, Division of Sports Medicine and Adult Reconstructive Surgery, Department of Orthopedic Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing 210093, China
- Branch of National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, Nanjing 210008, China
| |
Collapse
|
6
|
Toida K, Kushida W, Yamamoto H, Yamamoto K, Ishii K, Uesaka K, Kanaly RA, Kutsuna S, Ihara K, Fujita Y, Iwasaki H. The GGDEF protein Dgc2 suppresses both motility and biofilm formation in the filamentous cyanobacterium Leptolyngbya boryana. Microbiol Spectr 2023; 11:e0483722. [PMID: 37655901 PMCID: PMC10581220 DOI: 10.1128/spectrum.04837-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Accepted: 06/30/2023] [Indexed: 09/02/2023] Open
Abstract
Colony pattern formations of bacteria with motility manifest complicated morphological self-organization phenomena. Leptolyngbya boryana is a filamentous cyanobacterium, which has been used as a genetic model organism for studying metabolism including photosynthesis and nitrogen fixation. A widely used type strain [wild type (WT) in this article] of this species has not been reported to show any motile activity. However, we isolated a spontaneous mutant strain that shows active motility (gliding activity) to give rise to complicated colony patterns, including comet-like wandering clusters and disk-like rotating vortices on solid media. Whole-genome resequencing identified multiple mutations in the genome of the mutant strain. We confirmed that inactivation of the candidate gene dgc2 (LBDG_02920) in the WT background was sufficient to give rise to motility and morphologically complex colony patterns. This gene encodes a protein containing the GGDEF motif which is conserved at the catalytic domain of diguanylate cyclase (DGC). Although DGC has been reported to be involved in biofilm formation, the dgc2 mutant significantly facilitated biofilm formation, suggesting a role for the dgc2 gene in suppressing both gliding motility and biofilm formation. Thus, Leptolyngbya is expected to be an excellent genetic model for studying dynamic colony pattern formation and to provide novel insights into the role of DGC family genes in biofilm formation. IMPORTANCE Self-propelled bacteria often exhibit complex collective behaviors, such as formation of dense-moving clusters, which are exemplified by wandering comet-like and rotating disk-like colonies; however, the molecular details of how these structures are formed are scant. We found that a strain of the filamentous cyanobacterium Leptolyngbya deficient in the GGDEF protein gene dgc2 elicits motility and complex and dynamic colony pattern formation, including comet-like and disk-like clusters. Although c-di-GMP has been reported to activate biofilm formation in some bacterial species, disruption of dgc2 unexpectedly enhanced it, suggesting a novel role for this GGDEF protein for inhibiting both colony pattern formation and biofilm formation.
Collapse
Affiliation(s)
- Kazuma Toida
- Department of Electrical Engineering and Bioscience, Graduate School of Sciences and Engineering, TWIns, Waseda University, Tokyo, Japan
| | - Wakana Kushida
- Department of Electrical Engineering and Bioscience, Graduate School of Sciences and Engineering, TWIns, Waseda University, Tokyo, Japan
| | - Hiroki Yamamoto
- Department of Electrical Engineering and Bioscience, Graduate School of Sciences and Engineering, TWIns, Waseda University, Tokyo, Japan
| | - Kyoka Yamamoto
- Department of Electrical Engineering and Bioscience, Graduate School of Sciences and Engineering, TWIns, Waseda University, Tokyo, Japan
| | - Kaichi Ishii
- Department of Electrical Engineering and Bioscience, Graduate School of Sciences and Engineering, TWIns, Waseda University, Tokyo, Japan
| | - Kazuma Uesaka
- Center for Gene Research, Nagoya University, Nagoya, Japan
| | - Robert A. Kanaly
- Graduate School of Nanobioscience, Yokohama City University, Yokohama, Japan
| | - Shinsuke Kutsuna
- Graduate School of Nanobioscience, Yokohama City University, Yokohama, Japan
| | - Kunio Ihara
- Center for Gene Research, Nagoya University, Nagoya, Japan
| | - Yuichi Fujita
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Hideo Iwasaki
- Department of Electrical Engineering and Bioscience, Graduate School of Sciences and Engineering, TWIns, Waseda University, Tokyo, Japan
- metaPhorest, Bioaesthetics Platform, Waseda University, Tokyo, Japan
| |
Collapse
|
7
|
Risser DD. Hormogonium Development and Motility in Filamentous Cyanobacteria. Appl Environ Microbiol 2023; 89:e0039223. [PMID: 37199640 PMCID: PMC10304961 DOI: 10.1128/aem.00392-23] [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] [Indexed: 05/19/2023] Open
Abstract
Filamentous cyanobacteria exhibit some of the greatest developmental complexity observed in the prokaryotic domain. This includes the ability to differentiate nitrogen-fixing cells known as heterocysts, spore-like akinetes, and hormogonia, which are specialized motile filaments capable of gliding on solid surfaces. Hormogonia and motility play critical roles in several aspects of the biology of filamentous cyanobacteria, including dispersal, phototaxis, the formation of supracellular structures, and the establishment of nitrogen-fixing symbioses with plants. While heterocyst development has been investigated extensively at the molecular level, much less is known about akinete or hormogonium development and motility. This is due, in part, to the loss of developmental complexity during prolonged laboratory culture in commonly employed model filamentous cyanobacteria. In this review, recent progress in understanding the molecular level regulation of hormogonium development and motility in filamentous cyanobacteria is discussed, with a focus on experiments performed using the genetically tractable model filamentous cyanobacterium Nostoc punctiforme, which retains the developmental complexity of field isolates.
Collapse
Affiliation(s)
- Douglas D. Risser
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, Colorado, USA
| |
Collapse
|
8
|
Melkikh AV, Bondar VV. Mechanisms and models of movement of protocells and bacteria in the early stages of evolution. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2022; 175:3-13. [PMID: 35987420 DOI: 10.1016/j.pbiomolbio.2022.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 07/28/2022] [Accepted: 08/11/2022] [Indexed: 06/15/2023]
Abstract
A review of the physicochemical models of the movement of protocells and bacteria was performed. The mechanisms of gliding and movement based on flagella are considered. Based on the models, the average speed of movement of protocells and bacteria was calculated. A physicochemical model of bacterial gliding was constructed. The efficiency of the process of converting the energy of ATP into the energy of motion is estimated. A review of models of movement with the help of flagella was performed. A model has been constructed for converting ATP energy into proton and sodium motive forces, which, in turn, are converted into energy of rotor rotation. The problem of the accuracy of operation of nanomachines, on the basis of which the directed movement of bacteria occurs, is discussed. The considered models can be applied to create nanomotors for medical purposes.
Collapse
Affiliation(s)
- A V Melkikh
- Ural Federal University, Yekaterinburg, Russia.
| | - V V Bondar
- Ural Federal University, Yekaterinburg, Russia
| |
Collapse
|
9
|
Ibrahim HAH, Abou Elhassayeb HE, El-Sayed WMM. Potential functions and applications of diverse microbial exopolysaccharides in marine environments. J Genet Eng Biotechnol 2022; 20:151. [PMID: 36318392 PMCID: PMC9626724 DOI: 10.1186/s43141-022-00432-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 10/08/2022] [Indexed: 01/25/2023]
Abstract
Exopolysaccharides (EPSs) from microorganisms are essential harmless natural biopolymers used in applications including medications, nutraceuticals and functional foods, cosmetics, and insecticides. Several microbes can synthesize and excrete EPSs with chemical properties and structures that make them suitable for several important applications. Microbes secrete EPSs outside their cell walls, as slime or as a "jelly" into the extracellular medium. These EPS-producing microbes are ubiquitous and can be isolated from aquatic and terrestrial environments, such as freshwater, marine water, wastewater, and soils. They have also been isolated from extreme niches like hot springs, cold waters, halophilic environments, and salt marshes. Recently, microbial EPSs have attracted interest for their applications such as environmental bio-flocculants because they are degradable and nontoxic. However, further efforts are required for the cost-effective and industrial-scale commercial production of microbial EPSs. This review focuses on the exopolysaccharides obtained from several extremophilic microorganisms, their synthesis, and manufacturing optimization for better cost and productivity. We also explored their role and applications in interactions between several organisms.
Collapse
Affiliation(s)
- Hassan A. H. Ibrahim
- Marine Microbiology Department, National Institute of Oceanography and Fisheries (NIOF), Cairo, 11516 Egypt
| | - Hala E. Abou Elhassayeb
- Marine Microbiology Department, National Institute of Oceanography and Fisheries (NIOF), Cairo, 11516 Egypt
| | - Waleed M. M. El-Sayed
- Marine Microbiology Department, National Institute of Oceanography and Fisheries (NIOF), Cairo, 11516 Egypt
| |
Collapse
|
10
|
Faluweki MK, Goehring L. Structural mechanics of filamentous cyanobacteria. J R Soc Interface 2022; 19:20220268. [PMID: 35892203 PMCID: PMC9326267 DOI: 10.1098/rsif.2022.0268] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 07/05/2022] [Indexed: 06/15/2023] Open
Abstract
Filamentous cyanobacteria, forming long strands of connected cells, are one of the earliest and most successful forms of life on Earth. They exhibit self-organized behaviour, forming large-scale patterns in structures like biomats and stromatolites. The mechanical properties of these rigid structures have contributed to their biological success and are important to applications like algae-based biofuel production. For active polymers like these cyanobacteria, one of the most important mechanical properties is the bending modulus, or flexural rigidity. Here, we quantify the bending stiffness of three species of filamentous cyanobacteria, of order Oscillatoriales, using a microfluidic flow device where single filaments are deflected by fluid flow. This is complemented by measurements of Young's modulus of the cell wall, via nanoindentation, and the cell wall thickness. We find that the stiffness of the cyanobacteria is well-captured by a simple model of a flexible rod, with most stress carried by a rigid outer wall. Finally, we connect these results to the curved shapes that these cyanobacteria naturally take while gliding, and quantify the forces generated internally to maintain this shape. The measurements can be used to model interactions between cyanobacteria, or with their environment, and how their collective behaviour emerges from such interactions.
Collapse
Affiliation(s)
- Mixon K. Faluweki
- School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, UK
- Malawi Institute of Technology, Malawi University of Science and Technology, Limbe, Malawi
| | - Lucas Goehring
- School of Science and Technology, Nottingham Trent University, Nottingham NG11 8NS, UK
| |
Collapse
|
11
|
Microalgae-based oral microcarriers for gut microbiota homeostasis and intestinal protection in cancer radiotherapy. Nat Commun 2022; 13:1413. [PMID: 35301299 PMCID: PMC8931093 DOI: 10.1038/s41467-022-28744-4] [Citation(s) in RCA: 72] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 02/04/2022] [Indexed: 12/19/2022] Open
Abstract
Protecting the whole small intestine from radiation-induced intestinal injury during the radiotherapy of abdominal or pelvic solid tumors remains an unmet clinical need. Amifostine is a promising selective radioprotector for normal tissues. However, its oral application in intestinal radioprotection remains challenging. Herein, we use microalga Spirulina platensis as a microcarrier of Amifostine to construct an oral delivery system. The system shows comprehensive drug accumulation and effective radioprotection in the whole small intestine that is significantly superior to free drug and its enteric capsule, preventing the radiation-induced intestine injury and prolonging the survival without influencing the tumor regression. It also shows benefits on the gut microbiota homeostasis and long-term safety. Based on a readily available natural microcarrier, this work presents a convenient oral delivery system to achieve effective radioprotection for the whole small intestine, providing a competitive strategy with great clinical translation potential.
Collapse
|
12
|
Ji B. Towards environment-sustainable wastewater treatment and reclamation by the non-aerated microalgal-bacterial granular sludge process: Recent advances and future directions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:150707. [PMID: 34599950 DOI: 10.1016/j.scitotenv.2021.150707] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 09/23/2021] [Accepted: 09/27/2021] [Indexed: 06/13/2023]
Abstract
Currently, we are increasingly aware of the environmental unsustainability of the conventional wastewater treatment processes, e.g. extensive energy consumption and greenhouse gases emission. As such, the light-motivated non-aerated microalgal-bacterial granular sludge (MBGS) process has drawn extensive attention recently. This review aims to offer the important recent advances and future directions on the emerging non-aerated MBGS process for wastewater treatment and reclamation. The formation mechanism of MBGS from activated sludge is revealed to be the mobility under environmental stress such as shear force and nutrient deficiency. The key environmental factors affecting the non-aerated MBGS process are analyzed in terms with light, temperature, stirring and influent composition. Furthermore, sceneries of future outdoor processes by non-aerated MBGS are outlined. In turns out that the non-aerated MBGS offers a harmonious ecosystem to enrich the pollutants from wastewater to biomass, which can be potentially utilized as biofertilizer and feed for plant and animal, respectively. This review is expected to deepen our insights into the emerging non-aerated MBGS process for environment-sustainable wastewater treatment and reclamation.
Collapse
Affiliation(s)
- Bin Ji
- Department of Water and Wastewater Engineering, Wuhan University of Science and Technology, Wuhan 430065, China.
| |
Collapse
|
13
|
Yamamoto H, Fukasawa Y, Shoji Y, Hisamoto S, Kikuchi T, Takamatsu A, Iwasaki H. Scattered migrating colony formation in the filamentous cyanobacterium, Pseudanabaena sp. NIES-4403. BMC Microbiol 2021; 21:227. [PMID: 34399691 PMCID: PMC8365994 DOI: 10.1186/s12866-021-02183-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Accepted: 04/08/2021] [Indexed: 12/12/2022] Open
Abstract
Background Bacteria have been reported to exhibit complicated morphological colony patterns on solid media, depending on intracellular, and extracellular factors such as motility, cell propagation, and cell-cell interaction. We isolated the filamentous cyanobacterium, Pseudanabaena sp. NIES-4403 (Pseudanabaena, hereafter), that forms scattered (discrete) migrating colonies on solid media. While the scattered colony pattern has been observed in some bacterial species, the mechanism underlying such a pattern still remains obscure. Results We studied the morphology of Pseudanabaena migrating collectively and found that this species forms randomly scattered clusters varying in size and further consists of a mixture of comet-like wandering clusters and disk-like rotating clusters. Quantitative analysis of the formation of these wandering and rotating clusters showed that bacterial filaments tend to follow trajectories of previously migrating filaments at velocities that are dependent on filament length. Collisions between filaments occurred without crossing paths, which enhanced their nematic alignments, giving rise to bundle-like colonies. As cells increased and bundles aggregated, comet-like wandering clusters developed. The direction and velocity of the movement of cells in comet-like wandering clusters were highly coordinated. When the wandering clusters entered into a circular orbit, they turned into rotating clusters, maintaining a more stable location. Disk-like rotating clusters may rotate for days, and the speed of cells within a rotating cluster increases from the center to the outmost part of the cluster. Using a mathematical modeling with simplified assumption we reproduced some features of the scattered pattern including migrating clusters. Conclusion Based on these observations, we propose that Pseudanabaena forms scattered migrating colonies that undergo a series of transitions involving several morphological patterns. A simplified model is able to reproduce some features of the observed migrating clusters. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-021-02183-5.
Collapse
Affiliation(s)
- Hiroki Yamamoto
- Department of Electrical Engineering and Bioscience, Waseda University, Shinjuku, Tokyo, 162-8480, Japan
| | - Yuki Fukasawa
- Department of Electrical Engineering and Bioscience, Waseda University, Shinjuku, Tokyo, 162-8480, Japan
| | - Yu Shoji
- Department of Electrical Engineering and Bioscience, Waseda University, Shinjuku, Tokyo, 162-8480, Japan
| | - Shumpei Hisamoto
- Department of Electrical Engineering and Bioscience, Waseda University, Shinjuku, Tokyo, 162-8480, Japan
| | - Tomohiro Kikuchi
- Department of Electrical Engineering and Bioscience, Waseda University, Shinjuku, Tokyo, 162-8480, Japan
| | - Atsuko Takamatsu
- Department of Electrical Engineering and Bioscience, Waseda University, Shinjuku, Tokyo, 162-8480, Japan
| | - Hideo Iwasaki
- Department of Electrical Engineering and Bioscience, Waseda University, Shinjuku, Tokyo, 162-8480, Japan.
| |
Collapse
|
14
|
Heterocyst Septa Contain Large Nanopores That Are Influenced by the Fra Proteins in the Filamentous Cyanobacterium Anabaena sp. Strain PCC 7120. J Bacteriol 2021; 203:e0008121. [PMID: 33846119 DOI: 10.1128/jb.00081-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Multicellular heterocyst-forming cyanobacteria, such as Anabaena, grow as chains of cells forming filaments that, under diazotrophic conditions, contain two cell types: vegetative cells that perform oxygenic photosynthesis and N2-fixing heterocysts. Along the filament, the intercellular septa contain a thick peptidoglycan layer that forms septal disks. Proteinaceous septal junctions connect the cells in the filament traversing the septal disks through nanopores. The fraCDE operon encodes proteins needed to make long filaments in Anabaena. FraC and FraD, located at the intercellular septa, are involved in the formation of septal junctions. Using a superfolder-green fluorescent protein (GFP) fusion, we found in this study that FraE is mainly localized to the poles of the heterocysts, consistent with the requirement of FraE for constriction of the heterocyst poles to form the "heterocyst neck." A fraE insertional mutant was impaired by 22% to 38% in transfer of fluorescent calcein from vegetative cells to heterocysts. Septal disks were inspected in murein sacculi from heterocyst-enriched preparations. Unexpectedly, the diameter of the nanopores in heterocyst septa was about 1.5- to 2-fold larger than in vegetative cell septa. The number of these nanopores was 76% and 6% of the wild-type number in fraE and fraC fraD mutants, respectively. Our results show that FraE is mainly involved in heterocyst maturation, whereas FraC and FraD are needed for the formation of the large nanopores of heterocyst septa, as they are for vegetative cell nanopores. Additionally, arrays of small pores conceivably involved in polysaccharide export were observed close to the septal disks in the heterocyst murein sacculus preparations. IMPORTANCE Intercellular communication, an essential attribute of multicellularity, is required for diazotrophic growth in heterocyst-forming cyanobacteria such as Anabaena, in which the cells are connected by proteinaceous septal junctions that are structural analogs of metazoan connexons. The septal junctions allow molecular intercellular diffusion traversing the septal peptidoglycan through nanopores. In Anabaena the fraCDE operon encodes septal proteins involved in intercellular communication. FraC and FraD are components of the septal junctions along the filament, whereas here we show that FraE is mainly present at the heterocyst poles. We found that the intercellular septa in murein sacculi from heterocysts contain nanopores that are larger than those in vegetative cells, establishing a previously unknown difference between heterocyst and vegetative cell septa in Anabaena.
Collapse
|
15
|
Conradi FD, Mullineaux CW, Wilde A. The Role of the Cyanobacterial Type IV Pilus Machinery in Finding and Maintaining a Favourable Environment. Life (Basel) 2020; 10:life10110252. [PMID: 33114175 PMCID: PMC7690835 DOI: 10.3390/life10110252] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 10/18/2020] [Accepted: 10/21/2020] [Indexed: 12/11/2022] Open
Abstract
Type IV pili (T4P) are proteinaceous filaments found on the cell surface of many prokaryotic organisms and convey twitching motility through their extension/retraction cycles, moving cells across surfaces. In cyanobacteria, twitching motility is the sole mode of motility properly characterised to date and is the means by which cells perform phototaxis, the movement towards and away from directional light sources. The wavelength and intensity of the light source determine the direction of movement and, sometimes in concert with nutrient conditions, act as signals for some cyanobacteria to form mucoid multicellular assemblages. Formation of such aggregates or flocs represents an acclimation strategy to unfavourable environmental conditions and stresses, such as harmful light conditions or predation. T4P are also involved in natural transformation by exogenous DNA, secretion processes, and in cellular adaptation and survival strategies, further cementing the role of cell surface appendages. In this way, cyanobacteria are finely tuned by external stimuli to either escape unfavourable environmental conditions via phototaxis, exchange genetic material, and to modify their surroundings to fit their needs by forming multicellular assemblies.
Collapse
Affiliation(s)
- Fabian D. Conradi
- School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, UK; (F.D.C.); (C.W.M.)
| | - Conrad W. Mullineaux
- School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, UK; (F.D.C.); (C.W.M.)
| | - Annegret Wilde
- Institute of Biology III, University of Freiburg, Schänzlestr. 1, 79104 Freiburg; Germany
- Correspondence:
| |
Collapse
|
16
|
Igoshin OA, Chen J, Xing J, Liu J, Elston TC, Grabe M, Kim KS, Nirody JA, Rangamani P, Sun SX, Wang H, Wolgemuth C. Biophysics at the coffee shop: lessons learned working with George Oster. Mol Biol Cell 2019; 30:1882-1889. [PMID: 31322997 PMCID: PMC6727762 DOI: 10.1091/mbc.e19-02-0107] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Over the past 50 years, the use of mathematical models, derived from physical reasoning, to describe molecular and cellular systems has evolved from an art of the few to a cornerstone of biological inquiry. George Oster stood out as a pioneer of this paradigm shift from descriptive to quantitative biology not only through his numerous research accomplishments, but also through the many students and postdocs he mentored over his long career. Those of us fortunate enough to have worked with George agree that his sharp intellect, physical intuition, and passion for scientific inquiry not only inspired us as scientists but also greatly influenced the way we conduct research. We would like to share a few important lessons we learned from George in honor of his memory and with the hope that they may inspire future generations of scientists.
Collapse
Affiliation(s)
- Oleg A Igoshin
- Departments of Bioengineering, Biosciences, and Chemistry and Center for Theoretical Biological Physics, Rice University, Houston, TX 77005
| | - Jing Chen
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061
| | - Jianhua Xing
- Department of Computational and Systems Biology and UPMC-Hillman Cancer Center, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261
| | - Jian Liu
- Department of Cell Biology and Center for Cell Dynamics, School of Medicine, Johns Hopkins University, Baltimore, MD 21205
| | - Timothy C Elston
- Department of Pharmacology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Michael Grabe
- Cardiovascular Research Institute, School of Pharmacy, University of California, San Francisco, San Francisco, CA 94158
| | - Kenneth S Kim
- Lawrence Livermore National Laboratory, Livermore, CA 94550
| | - Jasmine A Nirody
- Center for Studies in Physics and Biology, Rockefeller University, New York, NY 10065
| | - Padmini Rangamani
- Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA 92093
| | - Sean X Sun
- Department of Mechanical Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD 21218
| | - Hongyun Wang
- Department of Applied Mathematics and Statistics, University of California, Santa Cruz, Santa Cruz, CA 95064
| | - Charles Wolgemuth
- Department of Physics and Department of Molecular and Cellular Biology, University of Arizona, Tucson, AZ 85721
| |
Collapse
|
17
|
Mikhailyuk T, Vinogradova O, Holzinger A, Glaser K, Samolov E, Karsten U. New record of the rare genus Crinalium Crow (Oscillatoriales, Cyanobacteria) from sand dunes of the Baltic Sea, Germany: epitypification and emendation of Crinalium magnum Fritsch et John based on an integrative approach. PHYTOTAXA 2019; 400:165-179. [PMID: 31501642 PMCID: PMC6733703 DOI: 10.11646/phytotaxa.400.3.4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Representatives of the Gomontiellaceae (Oscillatoriales) are rare and hence unstudied cyanobacteria with unusual morphology, distributed in terrestrial and aquatic habitats all over the world. Investigation of the group based on an integrative approach is only beginning, and to understand the actual biodiversity and ecology, a greater number of cultivated strains is necessary. However, some ecological traits of these cyanobacteria (e.g. low population densities, the absence of conspicuous growth in nature) led to methodological difficulties during isolation in culture. One species in the family Gomontiellaceae, Crinalium magnum Fritsch et John, is characterized by prominent wide and flattened trichomes, and represented by the non-authentic strain SAG 34.87. Detailed previous investigation of this strain clearly showed its morphological discrepancy with the original description of C. magnum and the genus Crinalium in general. The new isolate from maritime sand dunes of the Baltic Sea coast (Germany), however, revealed morphological characters completely corresponding with the diagnosis of C. magnum. Phylogenetic analysis based on 16S rRNA sequences indicated a position of the new strain inside Gomontiellaceae. Both morphology and ultrastructure of the strain are congruous with characters of the family. Epitypification and emendation of C. magnum are proposed since the ecology and habitat of the original strain are congruent with the type locality of this rare species (sand, Irish Sea coast, North Wales, UK). We expanded the description of C. magnum by details of the filament development and specified dimensional ranges for trichomes and cells, as well as by new data about the transversely striated structure of mucilaginous sheath.
Collapse
Affiliation(s)
- Tatiana Mikhailyuk
- M.G. Kholodny Institute of Botany, National Academy of Sciences of Ukraine, Tereschenkivska Str. 2, Kyiv 01004, Ukraine
- Department of Botany, Functional Plant Biology, University of Innsbruck, Sternwartestrasse 15, A-6020, Innsbruck, Austria
- University of Rostock, Institute of Biological Sciences, Department of Applied Ecology and Phycology, Albert-Einstein-Strasse 3, Rostock, D-18057, Germany
| | - Oksana Vinogradova
- M.G. Kholodny Institute of Botany, National Academy of Sciences of Ukraine, Tereschenkivska Str. 2, Kyiv 01004, Ukraine
| | - Andreas Holzinger
- Department of Botany, Functional Plant Biology, University of Innsbruck, Sternwartestrasse 15, A-6020, Innsbruck, Austria
| | - Karin Glaser
- University of Rostock, Institute of Biological Sciences, Department of Applied Ecology and Phycology, Albert-Einstein-Strasse 3, Rostock, D-18057, Germany
| | - Elena Samolov
- University of Rostock, Institute of Biological Sciences, Department of Applied Ecology and Phycology, Albert-Einstein-Strasse 3, Rostock, D-18057, Germany
| | - Ulf Karsten
- University of Rostock, Institute of Biological Sciences, Department of Applied Ecology and Phycology, Albert-Einstein-Strasse 3, Rostock, D-18057, Germany
| |
Collapse
|
18
|
Chaiyasitdhi A, Miphonpanyatawichok W, Riehle MO, Phatthanakun R, Surareungchai W, Kundhikanjana W, Kuntanawat P. The biomechanical role of overall-shape transformation in a primitive multicellular organism: A case study of dimorphism in the filamentous cyanobacterium Arthrospira platensis. PLoS One 2018; 13:e0196383. [PMID: 29746494 PMCID: PMC5945045 DOI: 10.1371/journal.pone.0196383] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 04/12/2018] [Indexed: 12/04/2022] Open
Abstract
Morphological transformations in primitive organisms have long been observed; however, its biomechanical roles are largely unexplored. In this study, we investigate the structural advantages of dimorphism in Arthrospira platensis, a filamentous multicellular cyanobacterium. We report that helical trichomes, the default shape, have a higher persistence length (Lp), indicating a higher resistance to bending or a large value of flexural rigidity (kf), the product of the local cell stiffness (E) and the moment of inertia of the trichomes’ cross-section (I). Through Atomic Force Microscopy (AFM), we determined that the E of straight and helical trichomes were the same. In contrast, our computational model shows that I is greatly dependent on helical radii, implying that trichome morphology is the major contributor to kf variation. According to our estimation, increasing the helical radii alone can increase kf by 2 orders of magnitude. We also observe that straight trichomes have improved gliding ability, due to its structure and lower kf. Our study shows that dimorphism provides mechanical adjustability to the organism and may allow it to thrive in different environmental conditions. The higher kf provides helical trichomes a better nutrient uptake through advection in aquatic environments. On the other hand, the lower kf improves the gliding ability of straight trichomes in aquatic environments, enabling it to chemotactically relocate to more favorable territories when it encounters certain environmental stresses. When more optimal conditions are encountered, straight trichomes can revert to their original helical form. Our study is one of the first to highlight the biomechanical role of an overall-shape transformation in cyanobacteria.
Collapse
Affiliation(s)
- Atitheb Chaiyasitdhi
- Biological Engineering Program, Faculty of Engineering, King Mongkut's University of Technology Thonburi, Bangkok, Thailand
| | - Wirat Miphonpanyatawichok
- Division of Biotechnology, School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok, Thailand
| | - Mathis Oliver Riehle
- Centre for Cell Engineering, Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | | | - Werasak Surareungchai
- Division of Biotechnology, School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok, Thailand
- Nanoscience & Nanotechnology Graduate Program, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok, Thailand
| | - Worasom Kundhikanjana
- School of Physics, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima, Thailand
| | - Panwong Kuntanawat
- Division of Biotechnology, School of Bioresources and Technology, King Mongkut's University of Technology Thonburi, Bangkok, Thailand
- Nanoscience & Nanotechnology Graduate Program, Faculty of Science, King Mongkut's University of Technology Thonburi, Bangkok, Thailand
- School of Biotechnology, Institute of Agricultural Technology, Suranaree University of Technology, Nakhon Ratchasima, Thailand
- * E-mail:
| |
Collapse
|
19
|
Bacterial Surface Spreading Is More Efficient on Nematically Aligned Polysaccharide Substrates. J Bacteriol 2018; 200:JB.00610-17. [PMID: 29311278 DOI: 10.1128/jb.00610-17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 12/18/2017] [Indexed: 01/07/2023] Open
Abstract
Biofilm-forming bacteria typically deposit layers of polysaccharides on the surfaces they inhabit; hence, polysaccharides are their immediate environment on such surfaces. Previously, we showed that many biofilm-forming bacteria preferentially spread in the direction of aligned and densely packed polysaccharide fibers in compressed substrates, a behavior we referred to as polymertropism. This arrangement of polysaccharide fibers is likely to be similar to that found in the "slime" trails deposited by many biofilm-forming bacteria and would explain previous observations that bacteria tend to follow these trails of polysaccharides. Here, we show that groups of cells or flares spread more rapidly on substrates containing aligned and densely packed polysaccharide fibers. Flares also persist longer, tend to hold their trajectories parallel to the long axes of polysaccharide fibers longer, and ultimately show an increase in displacement away from their origin. On the basis of these findings and others, we propose a model for polymertropism. Namely, we suggest that the packing of the aligned polymers increases the efficiency of surface spreading in the direction of the polymer's long axes; therefore, bacteria tend to spread more rapidly in this direction. Additional work suggests that bacteria can leverage polymertropism, and presumably more efficient surface spreading, for a survival advantage. In particular, when two bacterial species were placed in close proximity and in competition with each other, the ability of one species to move rapidly and directly away from the other by utilizing the aligned polymers of compressed agar substrates led to a clear survival benefit.IMPORTANCE The directed movement of bacteria on compressed substrates was first described in the 1940s and referred to as elasticotaxis (R. Y. Stanier, J Bacteriol 44:405-412, 1942). More recently, this behavior was referred to as polymertropism, as it seems to be a response to the nematic alignment and tight packing of polymers in the substrate (D. J. Lemon, X. Yang, P. Srivastava, Y. Y. Luk, A. G. Garza, Sci Rep 7:7643, 2017, https://doi.org/10.1038/s41598-017-07486-0). The data presented here suggest that bacteria are more efficient at surface spreading when the polymers in the substrate are arranged in this manner. These data also suggest that bacteria can leverage polymertropism, and presumably more efficient surface spreading, for a survival advantage. Namely, one bacterial species was able to use its strong polymertropism response to escape from and survive competition with another species that normally outcompetes it.
Collapse
|
20
|
Nishizuka H, Hashidoko Y. Comparison of Nostocean hormogonium induction and its motility on solid plates between agar and gellan gum at varying gel matrix concentrations. Biosci Biotechnol Biochem 2018; 82:525-531. [PMID: 29375025 DOI: 10.1080/09168451.2017.1420464] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
To establish a sensitive bioassay for Nostocean hormogonium induction, we compared the effectiveness of the morpho-differentiation induction on two gelled plates, agar and gellan gum, for anacardic acid C15:1-Δ8 decyl ester (1) (100 nmol/disc). On BG-110 (nitrogen-free) medium-based 0.6 and 0.8% agar plates, Nostoc sp. strain Yaku-1 isolated from a coralloid root of Cycas revoluta in Yakushima Island showed clear morpho-differentiation from filamentous aggregates into hormogonia, and the induced hormogonia dispersed within 24 h; however, similar hormogonium formation was not observed at agar concentrations of 1.0% or higher. Conversely, hormogonium induction was considerably more pronounced on gellan gum plates than those on agar plates through concentrations ranging from 0.6 to 1.6% even after 12 h of incubation, particularly active on the 0.8-1.0% gellan gum plates. Thus, gellan gum plates can achieve clear results within 12 h and are thus highly useful for primary screening for hormogonium-inducing factors (HIFs).
Collapse
Affiliation(s)
- Hiroaki Nishizuka
- a Graduate School of Agriculture , Hokkaido University , Sapporo , Japan
| | - Yasuyuki Hashidoko
- a Graduate School of Agriculture , Hokkaido University , Sapporo , Japan.,b Research Faculty of Agriculture , Hokkaido University , Sapporo , Japan
| |
Collapse
|
21
|
Cho YW, Gonzales A, Harwood TV, Huynh J, Hwang Y, Park JS, Trieu AQ, Italia P, Pallipuram VK, Risser DD. Dynamic localization of HmpF regulates type IV pilus activity and directional motility in the filamentous cyanobacterium Nostoc punctiforme. Mol Microbiol 2017; 106:252-265. [DOI: 10.1111/mmi.13761] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/03/2017] [Indexed: 01/14/2023]
Affiliation(s)
- Ye Won Cho
- Department of Biology; University of the Pacific; Stockton CA 95211 USA
| | - Alfonso Gonzales
- Department of Biology; University of the Pacific; Stockton CA 95211 USA
| | - Thomas V. Harwood
- Department of Biology; University of the Pacific; Stockton CA 95211 USA
| | - Jessica Huynh
- Department of Biology; University of the Pacific; Stockton CA 95211 USA
| | - Yeji Hwang
- Department of Biology; University of the Pacific; Stockton CA 95211 USA
| | - Jun Sang Park
- Department of Biology; University of the Pacific; Stockton CA 95211 USA
| | - Anthony Q. Trieu
- Department of Biology; University of the Pacific; Stockton CA 95211 USA
| | - Parth Italia
- Departments of Electrical and Computer Engineering; University of the Pacific; Stockton CA 95211 USA
| | - Vivek K. Pallipuram
- Departments of Electrical and Computer Engineering; University of the Pacific; Stockton CA 95211 USA
| | - Douglas D. Risser
- Department of Biology; University of the Pacific; Stockton CA 95211 USA
| |
Collapse
|
22
|
Lemon DJ, Yang X, Srivastava P, Luk YY, Garza AG. Polymertropism of rod-shaped bacteria: movement along aligned polysaccharide fibers. Sci Rep 2017; 7:7643. [PMID: 28801641 PMCID: PMC5554183 DOI: 10.1038/s41598-017-07486-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 06/16/2017] [Indexed: 01/11/2023] Open
Abstract
In nature, bacteria often live in surface-associated communities known as biofilms. Biofilm-forming bacteria typically deposit a layer of polysaccharide on the surfaces they inhabit; hence, polysaccharide is their immediate environment on many surfaces. In this study, we examined how the physical characteristics of polysaccharide substrates influence the behavior of the biofilm-forming bacterium Myxococcus xanthus. M. xanthus responds to the compression-induced deformation of polysaccharide substrates by preferentially spreading across the surface perpendicular to the axis of compression. Our results suggest that M. xanthus is not responding to the water that accumulates on the surface of the polysaccharide substrate after compression or to compression-induced changes in surface topography such as the formation of troughs. These directed surface movements do, however, consistently match the orientation of the long axes of aligned and tightly packed polysaccharide fibers in compressed substrates, as indicated by behavioral, birefringence and small angle X-ray scattering analyses. Therefore, we suggest that the directed movements are a response to the physical arrangement of the polymers in the substrate and refer to the directed movements as polymertropism. This behavior might be a common property of bacteria, as many biofilm-forming bacteria that are rod-shaped and motile on soft surfaces exhibit polymertropism.
Collapse
Affiliation(s)
- David J Lemon
- Department of Biology, Syracuse University, Syracuse, NY, 13244, United States
| | - Xingbo Yang
- Department of Physics, Syracuse University, Syracuse, NY, 13244, United States.,Department of Physics and Astronomy, Northwestern University, Evanston, IL, 60208, United States
| | - Pragya Srivastava
- Department of Physics, Syracuse University, Syracuse, NY, 13244, United States.,The Francis Crick Institute, London, NW1 1BF, United Kingdom
| | - Yan-Yeung Luk
- Department of Chemistry, Syracuse University, Syracuse, NY, 13244, United States.
| | - Anthony G Garza
- Department of Biology, Syracuse University, Syracuse, NY, 13244, United States.
| |
Collapse
|
23
|
Schuergers N, Mullineaux CW, Wilde A. Cyanobacteria in motion. CURRENT OPINION IN PLANT BIOLOGY 2017; 37:109-115. [PMID: 28472718 DOI: 10.1016/j.pbi.2017.03.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 03/21/2017] [Accepted: 03/24/2017] [Indexed: 05/17/2023]
Abstract
Cyanobacteria are able to move directly towards or away from a light source, a process called phototaxis. Recent studies have revealed that the spherical unicellular cyanobacterium Synechocystis sp. PCC 6803 exhibits a cell polarity in response to unidirectional illumination and that micro-optic properties of cyanobacterial cells are the basis of their directional light sensing. Further functional and physiological studies highlight a very complex control of cyanobacterial phototaxis by sensory proteins, histidine kinases and response regulators. Notably, PATAN domain response regulators appear to participate in directional control of phototaxis in the cyanobacterium Synechocystis sp. PCC 6803. In this review we explain the problem of directional light sensing at the small scale of bacteria and discuss our current understanding of signal transduction in cyanobacterial phototaxis.
Collapse
Affiliation(s)
- Nils Schuergers
- Laboratory of Nanobiotechnology, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Conrad W Mullineaux
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
| | - Annegret Wilde
- Institute of Biology III, University of Freiburg, D79104 Freiburg, Germany; BIOSS Centre of Biological Signalling Studies, University of Freiburg, 79106 Freiburg, Germany.
| |
Collapse
|
24
|
Fukushima SI, Morohoshi S, Hanada S, Matsuura K, Haruta S. Gliding motility driven by individual cell-surface movements in a multicellular filamentous bacterium Chloroflexus aggregans. FEMS Microbiol Lett 2016; 363:fnw056. [PMID: 26946537 DOI: 10.1093/femsle/fnw056] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/23/2016] [Indexed: 11/14/2022] Open
Abstract
Chloroflexus aggregans is an unbranched multicellular filamentous bacterium having the ability of gliding motility. The filament moves straightforward at a constant rate, ∼3 μm sec(-1) on solid surface and occasionally reverses the moving direction. In this study, we successfully detected movements of glass beads on the cell-surface along long axis of the filament indicating that the cell-surface movement was the direct force for gliding. Microscopic analyses found that the cell-surface movements were confined to a cell of the filament, and each cell independently moved and reversed the direction. To understand how the cellular movements determine the moving direction of the filament, we proposed a discrete-time stochastic model; sum of the directions of the cellular movements determines the moving direction of the filament only when the filament pauses, and after moving, the filament keeps the same directional movement until all the cells pause and/or move in the opposite direction. Monte Carlo simulation of this model showed that reversal frequency of longer filaments was relatively fixed to be low, but the frequency of shorter filaments varied widely. This simulation result appropriately explained the experimental observations. This study proposed the relevant mechanism adequately describing the motility of the multicellular filament in C. aggregans.
Collapse
Affiliation(s)
- Shun-Ichi Fukushima
- Department of Biological Sciences, Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
| | - Sho Morohoshi
- Department of Biological Sciences, Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
| | - Satoshi Hanada
- Department of Biological Sciences, Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
| | - Katsumi Matsuura
- Department of Biological Sciences, Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
| | - Shin Haruta
- Department of Biological Sciences, Graduate School of Science and Engineering, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397, Japan
| |
Collapse
|
25
|
|
26
|
Bohunická M, Mareš J, Hrouzek P, Urajová P, Lukeš M, Šmarda J, Komárek J, Gaysina LA, Strunecký O. A combined morphological, ultrastructural, molecular, and biochemical study of the peculiar family Gomontiellaceae (Oscillatoriales) reveals a new cylindrospermopsin-producing clade of cyanobacteria. JOURNAL OF PHYCOLOGY 2015; 51:1040-54. [PMID: 26987000 DOI: 10.1111/jpy.12354] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Accepted: 09/12/2015] [Indexed: 05/11/2023]
Abstract
Members of the morphologically unusual cyanobacterial family Gomontiellaceae were studied using a polyphasic approach. Cultured strains of Hormoscilla pringsheimii, Starria zimbabweënsis, Crinalium magnum, and Crinalium epipsammum were thoroughly examined, and the type specimen of the family, Gomontiella subtubulosa, was investigated. The results of morphological observations using both light microscopy and transmission electron microscopy were consistent with previous reports and provided evidence for the unique morphological and ultrastructural traits of this family. Analysis of the 16S rRNA gene confirmed the monophyletic origin of non-marine repre-sentatives of genera traditionally classified into this family. The family was phylogenetically placed among other groups of filamentous cyanobacterial taxa. The presence of cellulose in the cell wall was analyzed and confirmed in all cultured Gomontiellaceae members using Fourier transform infrared spectroscopy and fluorescence microscopy. Evaluation of toxins produced by the studied strains revealed the hepatotoxin cylindrospermopsin (CYN) in available strains of the genus Hormoscilla. Production of this compound in both Hormoscilla strains was detected using high-performance liquid chromatography in tandem with high resolution mass spectrometry and confirmed by positive PCR amplification of the cyrJ gene from the CYN biosynthetic cluster. To our knowledge, this is the first report of CYN production by soil cyanobacteria, establishing a previously unreported CYN-producing lineage. This study indicates that cyanobacteria of the family Gomontiellaceae form a separate but coherent cluster defined by numerous intriguing morphological, ultrastructural, and biochemical features, and exhibiting a toxic potential worthy of further investigation.
Collapse
Affiliation(s)
- Markéta Bohunická
- Faculty of Science, University of South Bohemia, Branišovská 1760, České Budějovice, CZ-370 05, Czech Republic
- Centre for Phycology, Institute of Botany of the CAS, v.v.i., Dukelská 135, Třeboň, CZ-379 82, Czech Republic
| | - Jan Mareš
- Faculty of Science, University of South Bohemia, Branišovská 1760, České Budějovice, CZ-370 05, Czech Republic
- Centre for Phycology, Institute of Botany of the CAS, v.v.i., Dukelská 135, Třeboň, CZ-379 82, Czech Republic
- Institute of Hydrobiology, Biology Centre of the CAS, v.v.i., Na Sádkách 7, České Budějovice, CZ-370 05, Czech Republic
| | - Pavel Hrouzek
- Center Algatech, Institute of Microbiology of the CAS, v.v.i., Opatovický mlýn, Třeboň, CZ-379 81, Czech Republic
| | - Petra Urajová
- Center Algatech, Institute of Microbiology of the CAS, v.v.i., Opatovický mlýn, Třeboň, CZ-379 81, Czech Republic
| | - Martin Lukeš
- Center Algatech, Institute of Microbiology of the CAS, v.v.i., Opatovický mlýn, Třeboň, CZ-379 81, Czech Republic
| | - Jan Šmarda
- Department of Biology, Faculty of Medicine, Masaryk University, Kamenice 5, Brno-Bohunice, CZ-625 00, Czech Republic
| | - Jiří Komárek
- Centre for Phycology, Institute of Botany of the CAS, v.v.i., Dukelská 135, Třeboň, CZ-379 82, Czech Republic
| | - Lira A Gaysina
- Department of Bioecology and Biological Education, M. Akmullah Bashkir State Pedagogical University, 450000 Ufa, Okt'yabrskoi revolucii 3a, Republic of Bashkortostan, Russian Federation
| | - Otakar Strunecký
- Centre for Phycology, Institute of Botany of the CAS, v.v.i., Dukelská 135, Třeboň, CZ-379 82, Czech Republic
| |
Collapse
|
27
|
Kato S, Ohkuma M, Powell DH, Krepski ST, Oshima K, Hattori M, Shapiro N, Woyke T, Chan CS. Comparative Genomic Insights into Ecophysiology of Neutrophilic, Microaerophilic Iron Oxidizing Bacteria. Front Microbiol 2015; 6:1265. [PMID: 26617599 PMCID: PMC4643136 DOI: 10.3389/fmicb.2015.01265] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 10/30/2015] [Indexed: 11/13/2022] Open
Abstract
Neutrophilic microaerophilic iron-oxidizing bacteria (FeOB) are thought to play a significant role in cycling of carbon, iron and associated elements in both freshwater and marine iron-rich environments. However, the roles of the neutrophilic microaerophilic FeOB are still poorly understood due largely to the difficulty of cultivation and lack of functional gene markers. Here, we analyze the genomes of two freshwater neutrophilic microaerophilic stalk-forming FeOB, Ferriphaselus amnicola OYT1 and Ferriphaselus strain R-1. Phylogenetic analyses confirm that these are distinct species within Betaproteobacteria; we describe strain R-1 and propose the name F. globulitus. We compare the genomes to those of two freshwater Betaproteobacterial and three marine Zetaproteobacterial FeOB isolates in order to look for mechanisms common to all FeOB, or just stalk-forming FeOB. The OYT1 and R-1 genomes both contain homologs to cyc2, which encodes a protein that has been shown to oxidize Fe in the acidophilic FeOB, Acidithiobacillus ferrooxidans. This c-type cytochrome common to all seven microaerophilic FeOB isolates, strengthening the case for its common utility in the Fe oxidation pathway. In contrast, the OYT1 and R-1 genomes lack mto genes found in other freshwater FeOB. OYT1 and R-1 both have genes that suggest they can oxidize sulfur species. Both have the genes necessary to fix carbon by the Calvin–Benson–Basshom pathway, while only OYT1 has the genes necessary to fix nitrogen. The stalk-forming FeOB share xag genes that may help form the polysaccharide structure of stalks. Both OYT1 and R-1 make a novel biomineralization structure, short rod-shaped Fe oxyhydroxides much smaller than their stalks; these oxides are constantly shed, and may be a vector for C, P, and metal transport to downstream environments. Our results show that while different FeOB are adapted to particular niches, freshwater and marine FeOB likely share common mechanisms for Fe oxidation electron transport and biomineralization pathways.
Collapse
Affiliation(s)
- Shingo Kato
- Department of Geological Sciences, University of Delaware, Newark DE, USA ; Japan Collection of Microorganisms, RIKEN BioResource Center Tsukuba, Japan
| | - Moriya Ohkuma
- Japan Collection of Microorganisms, RIKEN BioResource Center Tsukuba, Japan
| | - Deborah H Powell
- Delaware Biotechnology Institute, University of Delaware, Newark DE, USA
| | - Sean T Krepski
- Department of Geological Sciences, University of Delaware, Newark DE, USA
| | - Kenshiro Oshima
- Center for Omics and Bioinformatics, Graduate School of Frontier Sciences, University of Tokyo Kashiwa, Japan
| | - Masahira Hattori
- Center for Omics and Bioinformatics, Graduate School of Frontier Sciences, University of Tokyo Kashiwa, Japan
| | - Nicole Shapiro
- Department of Energy Joint Genome Institute, Walnut Creek CA, USA
| | - Tanja Woyke
- Department of Energy Joint Genome Institute, Walnut Creek CA, USA
| | - Clara S Chan
- Department of Geological Sciences, University of Delaware, Newark DE, USA
| |
Collapse
|
28
|
Wilde A, Mullineaux CW. Motility in cyanobacteria: polysaccharide tracks and Type IV pilus motors. Mol Microbiol 2015; 98:998-1001. [PMID: 26447922 DOI: 10.1111/mmi.13242] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/30/2015] [Indexed: 01/09/2023]
Abstract
Motility in cyanobacteria is useful for purposes that range from seeking out favourable light environments to establishing symbioses with plants and fungi. No known cyanobacterium is equipped with flagella, but a diverse range of species is able to 'glide' or 'twitch' across surfaces. Cyanobacteria with this capacity range from unicellular species to complex filamentous forms, including species such as Nostoc punctiforme, which can generate specialised motile filaments called hormogonia. Recent work on the model unicellular cyanobacterium Synechocystis sp. PCC 6803 has shown that its means of propulsion has much in common with the twitching motility of heterotrophs such as Pseudomonas and Myxococcus. Movement depends on Type IV pili, which are extended, adhere to the substrate and then retract to pull the cell across the surface. Previous work on filamentous cyanobacteria suggested a very different mechanism, with movement powered by the directional extrusion of polysaccharide from pores close to the cell junctions. Now a new report by Khayatan and colleagues in this issue of Molecular Microbiology suggests that the motility of Nostoc hormogonia has much more in common with Synechocystis than was previously thought. In both cases, polysaccharide secretion is important for preparing the surface, but the directional motive force comes from Type IV pili.
Collapse
Affiliation(s)
- Annegret Wilde
- Institute of Biology III, University of Freiburg, D79104, Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Conrad W Mullineaux
- School of Biological and Chemical Sciences, Queen Mary University of London, London, E1 4NS, UK
| |
Collapse
|
29
|
Khayatan B, Meeks JC, Risser DD. Evidence that a modified type IV pilus-like system powers gliding motility and polysaccharide secretion in filamentous cyanobacteria. Mol Microbiol 2015; 98:1021-36. [PMID: 26331359 DOI: 10.1111/mmi.13205] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/03/2015] [Indexed: 01/20/2023]
Abstract
In filamentous cyanobacteria, the mechanism of gliding motility is undefined but posited to be driven by a polysaccharide secretion system known as the junctional pore complex (JPC). Recent evidence implies that the JPC is a modified type IV pilus-like structure encoded for in part by genes in the hps locus. To test this hypothesis, we conducted genetic, cytological and comparative genomics studies on hps and pil genes in Nostoc punctiforme, a species in which motility is restricted to transiently differentiated filaments called hormogonia. Inactivation of most hps and pil genes abolished motility and abolished or drastically reduced secretion of hormogonium polysaccharide, and the subcellular localization of several Pil proteins in motile hormogonia corresponds to the site of the junctional pore complex. The non-motile ΔhpsE-G strain, which lacks three glycosyltransferases that synthesize hormogonium polysaccharide, could be complemented to motility by the addition of medium conditioned by wild-type hormogonia. Based on this result, we speculate that secretion of hormogonium polysaccharide facilitates but does not provide the motive force for gliding. Both the Hps and Pil homologs characterized in this study are almost universally conserved among filamentous cyanobacteria, with the Hps homologs rarely found in unicellular strains. These results support the theory that Hps and Pil proteins compose the JPC, a type IV pilus-like nanomotor that drives motility and polysaccharide secretion in filamentous cyanobacteria.
Collapse
Affiliation(s)
- Behzad Khayatan
- Department of Biology, University of the Pacific, Stockton, CA, 95211, USA
| | - John C Meeks
- Department of Microbiology, University of California, Davis, CA, 95616, USA
| | - Douglas D Risser
- Department of Biology, University of the Pacific, Stockton, CA, 95211, USA
| |
Collapse
|
30
|
Abstract
Chemotaxis affords motile cells the ability to rapidly respond to environmental challenges by navigating cells to niches favoring growth. Such a property results from the activities of dedicated signal transduction systems on the motility apparatus, such as flagella, type IV pili, and gliding machineries. Once cells have reached a niche with favorable conditions, they often stop moving and aggregate into complex communities termed biofilms. An intermediate and reversible stage that precedes commitment to permanent adhesion often includes transient cell-cell contacts between motile cells. Chemotaxis signaling has been implicated in modulating the transient aggregation of motile cells. Evidence further indicates that chemotaxis-dependent transient cell aggregation events are behavioral responses to changes in metabolic cues that temporarily prohibit permanent attachment by maintaining motility and chemotaxis. This minireview discusses a few examples illustrating the role of chemotaxis signaling in the initiation of cell-cell contacts in bacteria moving via flagella, pili, or gliding.
Collapse
|
31
|
Role of cyanobacterial exopolysaccharides in phototrophic biofilms and in complex microbial mats. Life (Basel) 2015; 5:1218-38. [PMID: 25837843 PMCID: PMC4500136 DOI: 10.3390/life5021218] [Citation(s) in RCA: 132] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 03/21/2015] [Accepted: 03/26/2015] [Indexed: 11/17/2022] Open
Abstract
Exopolysaccharides (EPSs) are an important class of biopolymers with great ecological importance. In natural environments, they are a common feature of microbial biofilms, where they play key protective and structural roles. As the primary colonizers of constrained environments, such as desert soils and lithic and exposed substrates, cyanobacteria are the first contributors to the synthesis of the EPSs constituting the extracellular polymeric matrix that favors the formation of microbial associations with varying levels of complexity called biofilms. Cyanobacterial colonization represents the first step for the formation of biofilms with different levels of complexity. In all of the possible systems in which cyanobacteria are involved, the synthesis of EPSs contributes a structurally-stable and hydrated microenvironment, as well as chemical/physical protection against biotic and abiotic stress factors. Notwithstanding the important roles of cyanobacterial EPSs, many aspects related to their roles and the relative elicited biotic and abiotic factors have still to be clarified. The aim of this survey is to outline the state-of-the-art of the importance of the cyanobacterial EPS excretion, both for the producing cells and for the microbial associations in which cyanobacteria are a key component.
Collapse
|
32
|
Schuergers N, Wilde A. Appendages of the cyanobacterial cell. Life (Basel) 2015; 5:700-15. [PMID: 25749611 PMCID: PMC4390875 DOI: 10.3390/life5010700] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2015] [Revised: 02/12/2015] [Accepted: 02/25/2015] [Indexed: 12/29/2022] Open
Abstract
Extracellular non-flagellar appendages, called pili or fimbriae, are widespread in gram-negative bacteria. They are involved in many different functions, including motility, adhesion, biofilm formation, and uptake of DNA. Sequencing data for a large number of cyanobacterial genomes revealed that most of them contain genes for pili synthesis. However, only for a very few cyanobacteria structure and function of these appendages have been analyzed. Here, we review the structure and function of type IV pili in Synechocystis sp. PCC 6803 and analyze the distribution of type IV pili associated genes in other cyanobacteria. Further, we discuss the role of the RNA-chaperone Hfq in pilus function and the presence of genes for the chaperone-usher pathway of pilus assembly in cyanobacteria.
Collapse
Affiliation(s)
- Nils Schuergers
- University of Freiburg, Institute of Biology III, Schänzlestr. 1, 79104 Freiburg, Germany.
| | - Annegret Wilde
- University of Freiburg, Institute of Biology III, Schänzlestr. 1, 79104 Freiburg, Germany.
| |
Collapse
|
33
|
Genetic analysis reveals the identity of the photoreceptor for phototaxis in hormogonium filaments of Nostoc punctiforme. J Bacteriol 2014; 197:782-91. [PMID: 25488296 DOI: 10.1128/jb.02374-14] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
In cyanobacterial Nostoc species, substratum-dependent gliding motility is confined to specialized nongrowing filaments called hormogonia, which differentiate from vegetative filaments as part of a conditional life cycle and function as dispersal units. Here we confirm that Nostoc punctiforme hormogonia are positively phototactic to white light over a wide range of intensities. N. punctiforme contains two gene clusters (clusters 2 and 2i), each of which encodes modular cyanobacteriochrome-methyl-accepting chemotaxis proteins (MCPs) and other proteins that putatively constitute a basic chemotaxis-like signal transduction complex. Transcriptional analysis established that all genes in clusters 2 and 2i, plus two additional clusters (clusters 1 and 3) with genes encoding MCPs lacking cyanobacteriochrome sensory domains, are upregulated during the differentiation of hormogonia. Mutational analysis determined that only genes in cluster 2i are essential for positive phototaxis in N. punctiforme hormogonia; here these genes are designated ptx (for phototaxis) genes. The cluster is unusual in containing complete or partial duplicates of genes encoding proteins homologous to the well-described chemotaxis elements CheY, CheW, MCP, and CheA. The cyanobacteriochrome-MCP gene (ptxD) lacks transmembrane domains and has 7 potential binding sites for bilins. The transcriptional start site of the ptx genes does not resemble a sigma 70 consensus recognition sequence; moreover, it is upstream of two genes encoding gas vesicle proteins (gvpA and gvpC), which also are expressed only in the hormogonium filaments of N. punctiforme.
Collapse
|
34
|
Virga EG. Dissipative shocks behind bacteria gliding. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2014; 372:rsta.2013.0360. [PMID: 25332385 DOI: 10.1098/rsta.2013.0360] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Gliding is a means of locomotion on rigid substrates used by a number of bacteria, including myxobacteria and cyanobacteria. One of the hypotheses advanced to explain this motility mechanism hinges on the role played by the slime filaments continuously extruded from gliding bacteria. This paper solves, in full, a non-linear mechanical theory that treats as dissipative shocks both the point where the extruded slime filament comes into contact with the substrate, called the filament's foot, and the pore on the bacterium outer surface from where the filament is ejected. I prove that kinematic compatibility for shock propagation requires that the bacterium uniform gliding velocity (relative to the substrate) and the slime ejecting velocity (relative to the bacterium) must be equal, a coincidence that seems to have already been observed.
Collapse
Affiliation(s)
- Epifanio G Virga
- Dipartimento di Matematica, Università di Pavia, Via Ferrata 5, 27100 Pavia, Italy
| |
Collapse
|
35
|
Cellular Dynamics Drives the Emergence of Supracellular Structure in the Cyanobacterium, Phormidium sp. KS. Life (Basel) 2014; 4:819-36. [PMID: 25460162 PMCID: PMC4284469 DOI: 10.3390/life4040819] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 11/12/2014] [Accepted: 11/19/2014] [Indexed: 11/23/2022] Open
Abstract
Motile filamentous cyanobacteria, such as Oscillatoria, Phormidium and Arthrospira, are ubiquitous in terrestrial and aquatic environments. As noted by Nägeli in 1860, many of them form complex three-dimensional or two-dimensional structures, such as biofilm, weed-like thalli, bundles of filaments and spirals, which we call supracellular structures. In all of these structures, individual filaments incessantly move back and forth. The structures are, therefore, macroscopic, dynamic structures that are continuously changing their microscopic arrangement of filaments. In the present study, we analyzed quantitatively the movement of individual filaments of Phormidium sp. KS grown on agar plates. Junctional pores, which have been proposed to drive cell movement by mucilage/slime secretion, were found to align on both sides of each septum. The velocity of movement was highest just after the reversal of direction and, then, attenuated exponentially to a final value before the next reversal of direction. This kinetics is compatible with the “slime gun” model. A higher agar concentration restricts the movement more severely and, thus, resulted in more spiral formation. The spiral is a robust form compatible with non-homogeneous movements of different parts of a long filament. We propose a model of spiral formation based on the microscopic movement of filaments.
Collapse
|
36
|
A model of filamentous cyanobacteria leading to reticulate pattern formation. Life (Basel) 2014; 4:433-56. [PMID: 25370380 PMCID: PMC4206854 DOI: 10.3390/life4030433] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Revised: 08/09/2014] [Accepted: 08/14/2014] [Indexed: 12/03/2022] Open
Abstract
The filamentous cyanobacterium, Pseudanabaena, has been shown to produce reticulate patterns that are thought to be the result of its gliding motility. Similar fossilized structures found in the geological record constitute some of the earliest signs of life on Earth. It is difficult to tie these fossils, which are billions of years old, directly to the specific microorganisms that built them. Identifying the physicochemical conditions and microorganism properties that lead microbial mats to form macroscopic structures can lead to a better understanding of the conditions on Earth at the dawn of life. In this article, a cell-based model is used to simulate the formation of reticulate patterns in cultures of Pseudanabaena. A minimal system of long and flexible trichomes capable of gliding motility is shown to be sufficient to produce stable patterns consisting of a network of streams. Varying model parameters indicate that systems with little to no cohesion, high trichome density and persistent movement are conducive to reticulate pattern formation, in conformance with experimental observations.
Collapse
|
37
|
Fiałkowska E, Pajdak-Stós A. Chemical and mechanical signals in inducingPhormidium(Cyanobacteria) defence against their grazers. FEMS Microbiol Ecol 2014; 89:659-69. [DOI: 10.1111/1574-6941.12367] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 05/30/2014] [Accepted: 06/05/2014] [Indexed: 11/29/2022] Open
Affiliation(s)
- Edyta Fiałkowska
- Institute of Environmental Sciences; Jagiellonian University; Kraków Poland
| | | |
Collapse
|
38
|
Risser DD, Chew WG, Meeks JC. Genetic characterization of thehmplocus, a chemotaxis-like gene cluster that regulates hormogonium development and motility inNostoc punctiforme. Mol Microbiol 2014; 92:222-33. [DOI: 10.1111/mmi.12552] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Douglas D. Risser
- Department of Biology; University of the Pacific; Stockton CA 95211 USA
| | - William G. Chew
- Department of Microbiology and Molecular Genetics; University of California; Davis CA 95616 USA
| | - John C. Meeks
- Department of Microbiology and Molecular Genetics; University of California; Davis CA 95616 USA
| |
Collapse
|
39
|
Baran R, Ivanova NN, Jose N, Garcia-Pichel F, Kyrpides NC, Gugger M, Northen TR. Functional genomics of novel secondary metabolites from diverse cyanobacteria using untargeted metabolomics. Mar Drugs 2013; 11:3617-31. [PMID: 24084783 PMCID: PMC3826126 DOI: 10.3390/md11103617] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Revised: 08/21/2013] [Accepted: 09/09/2013] [Indexed: 12/22/2022] Open
Abstract
Mass spectrometry-based metabolomics has become a powerful tool for the detection of metabolites in complex biological systems and for the identification of novel metabolites. We previously identified a number of unexpected metabolites in the cyanobacterium Synechococcus sp. PCC 7002, such as histidine betaine, its derivatives and several unusual oligosaccharides. To test for the presence of these compounds and to assess the diversity of small polar metabolites in other cyanobacteria, we profiled cell extracts of nine strains representing much of the morphological and evolutionary diversification of this phylum. Spectral features in raw metabolite profiles obtained by normal phase liquid chromatography coupled to mass spectrometry (MS) were manually curated so that chemical formulae of metabolites could be assigned. For putative identification, retention times and MS/MS spectra were cross-referenced with those of standards or available sprectral library records. Overall, we detected 264 distinct metabolites. These included indeed different betaines, oligosaccharides as well as additional unidentified metabolites with chemical formulae not present in databases of metabolism. Some of these metabolites were detected only in a single strain, but some were present in more than one. Genomic interrogation of the strains revealed that generally, presence of a given metabolite corresponded well with the presence of its biosynthetic genes, if known. Our results show the potential of combining metabolite profiling and genomics for the identification of novel biosynthetic genes.
Collapse
Affiliation(s)
- Richard Baran
- Life Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, MS977R0181A, Berkeley, CA 94720, USA; E-Mails: (R.B.); (N.J.)
| | - Natalia N. Ivanova
- DOE Joint Genome Institute, Walnut Creek, CA 94598, USA; E-Mails: (N.N.I.); (N.C.K.)
| | - Nick Jose
- Life Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, MS977R0181A, Berkeley, CA 94720, USA; E-Mails: (R.B.); (N.J.)
| | - Ferran Garcia-Pichel
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA; E-Mail:
| | - Nikos C. Kyrpides
- DOE Joint Genome Institute, Walnut Creek, CA 94598, USA; E-Mails: (N.N.I.); (N.C.K.)
| | - Muriel Gugger
- Institute Pasteur, Collection of Cyanobacteria, Paris Cedex 15 75724, France; E-Mail:
| | - Trent R. Northen
- Life Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, MS977R0181A, Berkeley, CA 94720, USA; E-Mails: (R.B.); (N.J.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-510-486-5240; Fax: +1-510-486-4545
| |
Collapse
|
40
|
Dhahri S, Ramonda M, Marlière C. In-situ determination of the mechanical properties of gliding or non-motile bacteria by atomic force microscopy under physiological conditions without immobilization. PLoS One 2013; 8:e61663. [PMID: 23593493 PMCID: PMC3625152 DOI: 10.1371/journal.pone.0061663] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Accepted: 03/12/2013] [Indexed: 11/19/2022] Open
Abstract
We present a study about AFM imaging of living, moving or self-immobilized bacteria in their genuine physiological liquid medium. No external immobilization protocol, neither chemical nor mechanical, was needed. For the first time, the native gliding movements of Gram-negative Nostoc cyanobacteria upon the surface, at speeds up to 900 µm/h, were studied by AFM. This was possible thanks to an improved combination of a gentle sample preparation process and an AFM procedure based on fast and complete force-distance curves made at every pixel, drastically reducing lateral forces. No limitation in spatial resolution or imaging rate was detected. Gram-positive and non-motile Rhodococcus wratislaviensis bacteria were studied as well. From the approach curves, Young modulus and turgor pressure were measured for both strains at different gliding speeds and are ranging from 20±3 to 105±5 MPa and 40±5 to 310±30 kPa depending on the bacterium and the gliding speed. For Nostoc, spatially limited zones with higher values of stiffness were observed. The related spatial period is much higher than the mean length of Nostoc nodules. This was explained by an inhomogeneous mechanical activation of nodules in the cyanobacterium. We also observed the presence of a soft extra cellular matrix (ECM) around the Nostoc bacterium. Both strains left a track of polymeric slime with variable thicknesses. For Rhodococcus, it is equal to few hundreds of nanometers, likely to promote its adhesion to the sample. While gliding, the Nostoc secretes a slime layer the thickness of which is in the nanometer range and increases with the gliding speed. This result reinforces the hypothesis of a propulsion mechanism based, for Nostoc cyanobacteria, on ejection of slime. These results open a large window on new studies of both dynamical phenomena of practical and fundamental interests such as the formation of biofilms and dynamic properties of bacteria in real physiological conditions.
Collapse
Affiliation(s)
- Samia Dhahri
- Géosciences Montpellier, University Montpellier 2, CNRS, Montpellier, France
| | - Michel Ramonda
- Centrale de Technologie en Micro et nanoélectronique, Laboratoire de Microscopie en Champ Proche, University Montpellier 2, Montpellier, France
| | - Christian Marlière
- Géosciences Montpellier, University Montpellier 2, CNRS, Montpellier, France
- Institut des Sciences Moléculaires d'Orsay, University Paris-Sud, CNRS, Orsay, France
- * E-mail:
| |
Collapse
|
41
|
Risser DD, Meeks JC. Comparative transcriptomics with a motility-deficient mutant leads to identification of a novel polysaccharide secretion system inNostoc punctiforme. Mol Microbiol 2013; 87:884-93. [DOI: 10.1111/mmi.12138] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/18/2012] [Indexed: 11/30/2022]
Affiliation(s)
- Douglas D. Risser
- Department of Microbiology; University of California; Davis; CA; 95616; USA
| | - John C. Meeks
- Department of Microbiology; University of California; Davis; CA; 95616; USA
| |
Collapse
|
42
|
Wet-surface-enhanced ellipsometric contrast microscopy identifies slime as a major adhesion factor during bacterial surface motility. Proc Natl Acad Sci U S A 2012; 109:10036-41. [PMID: 22665761 DOI: 10.1073/pnas.1120979109] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
In biology, the extracellular matrix (ECM) promotes both cell adhesion and specific recognition, which is essential for central developmental processes in both eukaryotes and prokaryotes. However, live studies of the dynamic interactions between cells and the ECM, for example during motility, have been greatly impaired by imaging limitations: mostly the ability to observe the ECM at high resolution in absence of specific staining by live microscopy. To solve this problem, we developed a unique technique, wet-surface enhanced ellipsometry contrast (Wet-SEEC), which magnifies the contrast of transparent organic materials deposited on a substrate (called Wet-surf) with exquisite sensitivity. We show that Wet-SEEC allows both the observation of unprocessed nanofilms as low as 0.2 nm thick and their accurate 3D topographic reconstructions, directly by standard light microscopy. We next used Wet-SEEC to image slime secretion, a poorly defined property of many prokaryotic and eukaryotic organisms that move across solid surfaces in absence of obvious extracellular appendages (gliding). Using combined Wet-SEEC and fluorescent-staining experiments, we observed slime deposition by gliding Myxococcus xanthus cells at unprecedented resolution. Altogether, the results revealed that in this bacterium, slime associates preferentially with the outermost components of the motility machinery and promotes its adhesion to the substrate on the ventral side of the cell. Strikingly, analogous roles have been proposed for the extracellular proteoglycans of gliding diatoms and apicomplexa, suggesting that slime deposition is a general means for gliding organisms to adhere and move over surfaces.
Collapse
|
43
|
Abstract
Bacterial gliding motility is the smooth movement of cells on solid surfaces unaided by flagella or pili. Many diverse groups of bacteria exhibit gliding, but the mechanism of gliding motility has remained a mystery since it was first observed more than a century ago. Recent studies on the motility of Myxococcus xanthus, a soil myxobacterium, suggest a likely mechanism for gliding in this organism. About forty M. xanthus genes were shown to be involved in gliding motility, and some of their protein products were labeled and localized within cells. These studies suggest that gliding motility in M. xanthus involves large multiprotein structural complexes, regulatory proteins, and cytoskeletal filaments. In this review, we summarize recent experiments that provide the basis for this emerging view of M. xanthus motility. We also discuss alternative models for gliding.
Collapse
Affiliation(s)
- Beiyan Nan
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, California 94720, USA.
| | | |
Collapse
|
44
|
Wu Y, Jiang Y, Kaiser AD, Alber M. Self-organization in bacterial swarming: lessons from myxobacteria. Phys Biol 2011; 8:055003. [PMID: 21832807 DOI: 10.1088/1478-3975/8/5/055003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
When colonizing surfaces, many bacteria are able to self-organize into an actively expanding biofilm, in which millions of cells move smoothly and orderly at high densities. This phenomenon is known as bacterial swarming. Despite the apparent resemblance to patterns seen in liquid crystals, the dynamics of bacterial swarming cannot be explained by theories derived from equilibrium statistical mechanics. To understand how bacteria swarm, a central question is how order emerges in dense and initially disorganized populations of bacterial cells. Here we briefly review recent efforts, with integrated computational and experimental approaches, in addressing this question.
Collapse
Affiliation(s)
- Yilin Wu
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | | | | | | |
Collapse
|
45
|
Tamulonis C, Postma M, Kaandorp J. Modeling filamentous cyanobacteria reveals the advantages of long and fast trichomes for optimizing light exposure. PLoS One 2011; 6:e22084. [PMID: 21789215 PMCID: PMC3138769 DOI: 10.1371/journal.pone.0022084] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Accepted: 06/14/2011] [Indexed: 11/18/2022] Open
Abstract
Cyanobacteria form a very large and diverse phylum of prokaryotes that perform oxygenic photosynthesis. Many species of cyanobacteria live colonially in long trichomes of hundreds to thousands of cells. Of the filamentous species, many are also motile, gliding along their long axis, and display photomovement, by which a trichome modulates its gliding according to the incident light. The latter has been found to play an important role in guiding the trichomes to optimal lighting conditions, which can either inhibit the cells if the incident light is too weak, or damage the cells if too strong. We have developed a computational model for gliding filamentous photophobic cyanobacteria that allows us to perform simulations on the scale of a Petri dish using over 10(5) individual trichomes. Using the model, we quantify the effectiveness of one commonly observed photomovement strategy--photophobic responses--in distributing large populations of trichomes optimally over a light field. The model predicts that the typical observed length and gliding speeds of filamentous cyanobacteria are optimal for the photophobic strategy. Therefore, our results suggest that not just photomovement but also the trichome shape itself improves the ability of the cyanobacteria to optimize their light exposure.
Collapse
Affiliation(s)
- Carlos Tamulonis
- Informatics Institute, University of Amsterdam, Amsterdam, The Netherlands.
| | | | | |
Collapse
|
46
|
Kupriyanova EV, Sinetova MA, Markelova AG, Allakhverdiev SI, Los DA, Pronina NA. Extracellular β-class carbonic anhydrase of the alkaliphilic cyanobacterium Microcoleus chthonoplastes. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2011; 103:78-86. [DOI: 10.1016/j.jphotobiol.2011.01.021] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Revised: 01/21/2011] [Accepted: 01/24/2011] [Indexed: 11/16/2022]
|
47
|
Gliding motility revisited: how do the myxobacteria move without flagella? Microbiol Mol Biol Rev 2010; 74:229-49. [PMID: 20508248 DOI: 10.1128/mmbr.00043-09] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In bacteria, motility is important for a wide variety of biological functions such as virulence, fruiting body formation, and biofilm formation. While most bacteria move by using specialized appendages, usually external or periplasmic flagella, some bacteria use other mechanisms for their movements that are less well characterized. These mechanisms do not always exhibit obvious motility structures. Myxococcus xanthus is a motile bacterium that does not produce flagella but glides slowly over solid surfaces. How M. xanthus moves has remained a puzzle that has challenged microbiologists for over 50 years. Fortunately, recent advances in the analysis of motility mutants, bioinformatics, and protein localization have revealed likely mechanisms for the two M. xanthus motility systems. These results are summarized in this review.
Collapse
|
48
|
Dunker R, Røy H, Jørgensen BB. Temperature regulation of gliding motility in filamentous sulfur bacteria, Beggiatoa spp. FEMS Microbiol Ecol 2010; 73:234-42. [DOI: 10.1111/j.1574-6941.2010.00887.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
|
49
|
Kurk T, Adams DG, Connell SD, Thomson NH. Three-channel false colour AFM images for improved interpretation of complex surfaces: a study of filamentous cyanobacteria. Ultramicroscopy 2010; 110:718-22. [PMID: 20303215 DOI: 10.1016/j.ultramic.2010.02.038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Imaging signals derived from the atomic force microscope (AFM) are typically presented as separate adjacent images with greyscale or pseudo-colour palettes. We propose that information-rich false-colour composites are a useful means of presenting three-channel AFM image data. This method can aid the interpretation of complex surfaces and facilitate the perception of information that is convoluted across data channels. We illustrate this approach with images of filamentous cyanobacteria imaged in air and under aqueous buffer, using both deflection-modulation (contact) mode and amplitude-modulation (tapping) mode. Topography-dependent contrast in the error and tertiary signals aids the interpretation of the topography signal by contributing additional data, resulting in a more detailed image, and by showing variations in the probe-surface interaction. Moreover, topography-independent contrast and topography-dependent contrast in the tertiary data image (phase or friction) can be distinguished more easily as a consequence of the three dimensional colour-space.
Collapse
Affiliation(s)
- Toby Kurk
- School of Physics & Astronomy, University of Leeds, Leeds, West Yorkshire, United Kingdom.
| | | | | | | |
Collapse
|
50
|
Abstract
We have developed a simple chemical system capable of self-movement in order to study the physicochemical origins of movement. We propose how this system may be useful in the study of minimal perception and cognition. The system consists simply of an oil droplet in an aqueous environment. A chemical reaction within the oil droplet induces an instability, the symmetry of the oil droplet breaks, and the droplet begins to move through the aqueous phase. The complement of physical phenomena that is then generated indicates the presence of feedback cycles that, as will be argued, form the basis for self-regulation, homeostasis, and perhaps an extended form of autopoiesis. We discuss the result that simple chemical systems are capable of sensory-motor coupling and possess a homeodynamic state from which cognitive processes may emerge.
Collapse
Affiliation(s)
- Martin M Hanczyc
- University of Southern Denmark, Institute of Physics and Chemistry, Odense M, Denmark.
| | | |
Collapse
|