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Zeytuni N, Cronin S, Lefèvre CT, Arnoux P, Baran D, Shtein Z, Davidov G, Zarivach R. MamA as a Model Protein for Structure-Based Insight into the Evolutionary Origins of Magnetotactic Bacteria. PLoS One 2015; 10:e0130394. [PMID: 26114501 PMCID: PMC4482739 DOI: 10.1371/journal.pone.0130394] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 05/20/2015] [Indexed: 02/01/2023] Open
Abstract
MamA is a highly conserved protein found in magnetotactic bacteria (MTB), a diverse group of prokaryotes capable of navigating according to magnetic fields – an ability known as magnetotaxis. Questions surround the acquisition of this magnetic navigation ability; namely, whether it arose through horizontal or vertical gene transfer. Though its exact function is unknown, MamA surrounds the magnetosome, the magnetic organelle embedding a biomineralised nanoparticle and responsible for magnetotaxis. Several structures for MamA from a variety of species have been determined and show a high degree of structural similarity. By determining the structure of MamA from Desulfovibrio magneticus RS-1 using X-ray crystallography, we have opened up the structure-sequence landscape. As such, this allows us to perform structural- and phylogenetic-based analyses using a variety of previously determined MamA from a diverse range of MTB species across various phylogenetic groups. We found that MamA has remained remarkably constant throughout evolution with minimal change between different taxa despite sequence variations. These findings, coupled with the generation of phylogenetic trees using both amino acid sequences and 16S rRNA, indicate that magnetotaxis likely did not spread via horizontal gene transfer and instead has a significantly earlier, primordial origin.
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Affiliation(s)
- Natalie Zeytuni
- Department of Life Sciences and The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Samuel Cronin
- Department of Life Sciences and The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Christopher T. Lefèvre
- CEA/CNRS/Aix-Marseille Université, UMR 7265 Biologie Végétale et Microbiologie Environnementales, Laboratoire de Bioénergétique Cellulaire, Saint Paul les Durance, France
| | - Pascal Arnoux
- CEA/CNRS/Aix-Marseille Université, UMR 7265 Biologie Végétale et Microbiologie Environnementales, Laboratoire de Bioénergétique Cellulaire, Saint Paul les Durance, France
| | - Dror Baran
- Department of Life Sciences and The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Zvi Shtein
- Department of Life Sciences and The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Geula Davidov
- Department of Life Sciences and The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Raz Zarivach
- Department of Life Sciences and The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer Sheva, Israel
- * E-mail:
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202
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Mériaux S, Boucher M, Marty B, Lalatonne Y, Prévéral S, Motte L, Lefèvre CT, Geffroy F, Lethimonnier F, Péan M, Garcia D, Adryanczyk-Perrier G, Pignol D, Ginet N. Magnetosomes, biogenic magnetic nanomaterials for brain molecular imaging with 17.2 T MRI scanner. Adv Healthc Mater 2015; 4:1076-83. [PMID: 25676134 DOI: 10.1002/adhm.201400756] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 01/13/2015] [Indexed: 12/28/2022]
Abstract
The fast development of sensitive molecular diagnostic tools is currently paving the way for a personalized medicine. A new class of ultrasensitive magnetic resonance imaging (MRI) T₂-contrast agents based on magnetosomes, magnetite nanocrystals biomineralized by magnetotactic bacteria, is proposed here. The contrast agents can be injected into the blood circulation and detected in the picomolar range. Purified magnetosomes are water-dispersible and stable within physiological conditions and exhibit at 17.2 T a transverse relaxivity r₂ four times higher than commercial ferumoxide. The subsequent gain in sensitivity by T₂(*) -weighted imaging at 17.2 T of the mouse brain vasculature is evidenced in vivo after tail vein injection of magnetosomes representing a low dose of iron (20 μmoliron kg(-1)), whereas no such phenomenon with the same dose of ferumoxide is observed. Preclinical studies of human pathologies in animal models will benefit from the combination of high magnetic field MRI with sensitive, low dose, easy-to-produce biocompatible contrast agents derived from bacterial magnetosomes.
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Affiliation(s)
- Sébastien Mériaux
- CEA/DSV/I BM/NeuroSpin/UNIRS; CEA Saclay; 91191 Gif-sur-Yvette Cedex France
| | - Marianne Boucher
- CEA/DSV/I BM/NeuroSpin/UNIRS; CEA Saclay; 91191 Gif-sur-Yvette Cedex France
| | - Benjamin Marty
- Institute of Myology (NMR Laboratory); CEA/DSV/I BM/MIRCen (IdM NMR Laboratory); UPMC Paris 6 University; 75013 Paris France
| | - Yoann Lalatonne
- Paris 13 University/Sorbonne Paris Cité/CSPBAT/CNRS (UMR7244); 93017 Bobigny Cedex France
| | - Sandra Prévéral
- CEA/Aix-Marseille University/CNRS (UMR7265); DSV/IBEB/SBVME/LBC; CEA Cadarache; 13108 Saint-Paul-lez-Durance Cedex France
| | - Laurence Motte
- Paris 13 University/Sorbonne Paris Cité/CSPBAT/CNRS (UMR7244); 93017 Bobigny Cedex France
| | - Christopher T. Lefèvre
- CEA/Aix-Marseille University/CNRS (UMR7265); DSV/IBEB/SBVME/LBC; CEA Cadarache; 13108 Saint-Paul-lez-Durance Cedex France
| | - Françoise Geffroy
- CEA/DSV/I BM/NeuroSpin/UNIRS; CEA Saclay; 91191 Gif-sur-Yvette Cedex France
| | | | - Michel Péan
- CEA/Aix-Marseille University/CNRS (UMR7265); DSV/IBEB/SBVME/LBC; CEA Cadarache; 13108 Saint-Paul-lez-Durance Cedex France
| | - Daniel Garcia
- CEA/Aix-Marseille University/CNRS (UMR7265); DSV/IBEB/SBVME/LBC; CEA Cadarache; 13108 Saint-Paul-lez-Durance Cedex France
| | - Géraldine Adryanczyk-Perrier
- CEA/Aix-Marseille University/CNRS (UMR7265); DSV/IBEB/SBVME/LBC; CEA Cadarache; 13108 Saint-Paul-lez-Durance Cedex France
| | - David Pignol
- CEA/Aix-Marseille University/CNRS (UMR7265); DSV/IBEB/SBVME/LBC; CEA Cadarache; 13108 Saint-Paul-lez-Durance Cedex France
| | - Nicolas Ginet
- CEA/Aix-Marseille University/CNRS (UMR7265); DSV/IBEB/SBVME/LBC; CEA Cadarache; 13108 Saint-Paul-lez-Durance Cedex France
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203
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Faivre D, Godec TU. Bakterien und Weichtiere: Prinzipien der Biomineralisation von Eisenoxid-Materialien. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201408900] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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204
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Lin W, Pan Y. A putative greigite-type magnetosome gene cluster from the candidate phylum Latescibacteria. ENVIRONMENTAL MICROBIOLOGY REPORTS 2015; 7:237-242. [PMID: 25382584 DOI: 10.1111/1758-2229.12234] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 10/28/2014] [Indexed: 06/04/2023]
Abstract
The intracellular biomineralization of magnetite and/or greigite magnetosomes in magnetotactic bacteria (MTB) is strictly controlled by a group of conserved genes, termed magnetosome genes, which are organized as clusters (or islands) in MTB genomes. So far, all reported MTB are affiliated within the Proteobacteria phylum, the Nitrospirae phylum and the candidate division OP3. Here, we report the discovery of a putative magnetosome gene cluster structure from the draft genome of an uncultivated bacterium belonging to the candidate phylum Latescibacteria (formerly candidate division WS3) recently recovered by Rinke and colleagues, which contains 10 genes with homology to magnetosome mam genes of magnetotactic Proteobacteria and Nitrospirae. Moreover, these genes are phylogenetically closely related to greigite-type magnetosome genes that were only found from the Deltaproteobacteria MTB before, suggesting that the greigite genes may originate earlier than previously imagined. These findings indicate that some members of Latescibacteria may be capable of forming greigite magnetosomes, and thus may play previously unrecognized roles in environmental iron and sulfur cycles. The conserved genomic structure of magnetosome gene cluster in Latescibacteria phylum supports the hypothesis of horizontal transfer of these genes among distantly related bacterial groups in nature.
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Affiliation(s)
- Wei Lin
- Biogeomagnetism Group, Paleomagnetism and Geochronology Laboratory, Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China; France-China Bio-Mineralization and Nano-Structures Laboratory, Chinese Academy of Sciences, Beijing, 100029, China
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205
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Aliaga Goltsman DS, Comolli LR, Thomas BC, Banfield JF. Community transcriptomics reveals unexpected high microbial diversity in acidophilic biofilm communities. THE ISME JOURNAL 2015; 9:1014-23. [PMID: 25361394 PMCID: PMC4817702 DOI: 10.1038/ismej.2014.200] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 09/08/2014] [Accepted: 09/16/2014] [Indexed: 12/21/2022]
Abstract
A fundamental question in microbial ecology relates to community structure, and how this varies across environment types. It is widely believed that some environments, such as those at very low pH, host simple communities based on the low number of taxa, possibly due to the extreme environmental conditions. However, most analyses of species richness have relied on methods that provide relatively low ribosomal RNA (rRNA) sampling depth. Here we used community transcriptomics to analyze the microbial diversity of natural acid mine drainage biofilms from the Richmond Mine at Iron Mountain, California. Our analyses target deep pools of rRNA gene transcripts recovered from both natural and laboratory-grown biofilms across varying developmental stages. In all, 91.8% of the ∼ 254 million Illumina reads mapped to rRNA genes represented in the SILVA database. Up to 159 different taxa, including Bacteria, Archaea and Eukaryotes, were identified. Diversity measures, ordination and hierarchical clustering separate environmental from laboratory-grown biofilms. In part, this is due to the much larger number of rare members in the environmental biofilms. Although Leptospirillum bacteria generally dominate biofilms, we detect a wide variety of other Nitrospira organisms present at very low abundance. Bacteria from the Chloroflexi phylum were also detected. The results indicate that the primary characteristic that has enabled prior extensive cultivation-independent 'omic' analyses is not simplicity but rather the high dominance by a few taxa. We conclude that a much larger variety of organisms than previously thought have adapted to this extreme environment, although only few are selected for at any one time.
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Affiliation(s)
| | - Luis R Comolli
- Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Brian C Thomas
- Environmental Science, Policy, and Management, University of California, Berkeley, CA, USA
| | - Jillian F Banfield
- Environmental Science, Policy, and Management, University of California, Berkeley, CA, USA
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206
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Li K, Chen C, Chen C, Wang Y, Wei Z, Pan W, Song T. Magnetosomes extracted from Magnetospirillum magneticum strain AMB-1 showed enhanced peroxidase-like activity under visible-light irradiation. Enzyme Microb Technol 2015; 72:72-8. [PMID: 25837510 DOI: 10.1016/j.enzmictec.2015.02.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Revised: 02/26/2015] [Accepted: 02/27/2015] [Indexed: 11/15/2022]
Abstract
Magnetosomes are intracellular structures produced by magnetotactic bacteria and are magnetic nanoparticles surrounded by a lipid bilayer membrane. Magnetosomes reportedly possess intrinsic enzyme mimetic activity similar to that found in horseradish peroxidase (HRP) and can scavenge reactive oxygen species depending on peroxidase activity. Our previous study has demonstrated the phototaxis characteristics of Magnetospirillum magneticum strain AMB-1 cells, but the mechanism is not well understood. Therefore, we studied the relationship between visible-light irradiation and peroxidase-like activity of magnetosomes extracted from M. magneticum strain AMB-1. We then compared this characteristic with that of HRP, iron ions, and naked magnetosomes using 3,3',5,5'-tetramethylbenzidine as a peroxidase substrate in the presence of H2O2. Results showed that HRP and iron ions had different activities from those of magnetosomes and naked magnetosomes when exposed to visible-light irradiation. Magnetosomes and naked magnetosomes had enhanced peroxidase-like activities under visible-light irradiation, but magnetosomes showed less affinity toward substrates than naked magnetosomes under visible-light irradiation. These results suggested that the peroxidase-like activity of magnetosomes may follow an ordered ternary mechanism rather than a ping-pong mechanism. This finding may provide new insight into the function of magnetosomes in the phototaxis in magnetotactic bacteria.
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Affiliation(s)
- Kefeng Li
- Beijing Key Laboratory of Bioelectromagnetism, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China; Shandong Sport University, Jinan 250102, China
| | - Chuanfang Chen
- Beijing Key Laboratory of Bioelectromagnetism, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China; France-China Bio-Mineralization and Nano-Structures Laboratory, Beijing 100193, China
| | - Changyou Chen
- Beijing Key Laboratory of Bioelectromagnetism, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yuzhan Wang
- Beijing Key Laboratory of Bioelectromagnetism, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China
| | - Zhao Wei
- Beijing Key Laboratory of Bioelectromagnetism, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Weidong Pan
- Beijing Key Laboratory of Bioelectromagnetism, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China; France-China Bio-Mineralization and Nano-Structures Laboratory, Beijing 100193, China
| | - Tao Song
- Beijing Key Laboratory of Bioelectromagnetism, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China; France-China Bio-Mineralization and Nano-Structures Laboratory, Beijing 100193, China.
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207
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Positioning the flagellum at the center of a dividing cell to combine bacterial division with magnetic polarity. mBio 2015; 6:e02286. [PMID: 25714711 PMCID: PMC4358019 DOI: 10.1128/mbio.02286-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Faithful replication of all structural features is a sine qua non condition for the success of bacterial reproduction by binary fission. For some species, a key challenge is to replicate and organize structures with multiple polarities. Polarly flagellated magnetotactic bacteria are the prime example of organisms dealing with such a dichotomy; they have the challenge of bequeathing two types of polarities to their daughter cells: magnetic and flagellar polarities. Indeed, these microorganisms align and move in the Earth’s magnetic field using an intracellular chain of nano-magnets that imparts a magnetic dipole to the cell. The paradox is that, after division occurs in cells, if the new flagellum is positioned opposite to the old pole devoid of a flagellum during cell division, the two daughter cells will have opposite magnetic polarities with respect to the positions of their flagella. Here we show that magnetotactic bacteria of the class Gammaproteobacteria pragmatically solve this problem by synthesizing a new flagellum at the division site. In addition, we model this particular structural inheritance during cell division. This finding opens up new questions regarding the molecular aspects of the new division mechanism, the way other polarly flagellated magnetotactic bacteria control the rotational direction of their flagella, and the positioning of organelles. Magnetotactic bacteria produce chains of magnetic nanoparticles that endow the cells with a magnetic dipole, a “compass” used for navigation. This feature, however, also drastically complicates cellular division in the case of polarly flagellated bacteria. In this case, the bacteria have to pass on to their daughter cells two types of cellular polarities simultaneously, their magnetic polarity and the polarity of their motility apparatus. We show here that magnetotactic bacteria of the Gammaproteobacteria class pragmatically solve this problem by synthesizing the new flagellum at the division site, a division scheme never observed so far in bacteria. Even though the molecular mechanisms behind this scheme cannot be resolved at the moment due to the lack of genetic tools, this discovery provides a new window into the organizational complexity of simple organisms.
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208
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Magnetotactic bacteria as potential sources of bioproducts. Mar Drugs 2015; 13:389-430. [PMID: 25603340 PMCID: PMC4306944 DOI: 10.3390/md13010389] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 12/17/2014] [Indexed: 11/16/2022] Open
Abstract
Magnetotactic bacteria (MTB) produce intracellular organelles called magnetosomes which are magnetic nanoparticles composed of magnetite (Fe3O4) or greigite (Fe3S4) enveloped by a lipid bilayer. The synthesis of a magnetosome is through a genetically controlled process in which the bacterium has control over the composition, direction of crystal growth, and the size and shape of the mineral crystal. As a result of this control, magnetosomes have narrow and uniform size ranges, relatively specific magnetic and crystalline properties, and an enveloping biological membrane. These features are not observed in magnetic particles produced abiotically and thus magnetosomes are of great interest in biotechnology. Most currently described MTB have been isolated from saline or brackish environments and the availability of their genomes has contributed to a better understanding and culturing of these fastidious microorganisms. Moreover, genome sequences have allowed researchers to study genes related to magnetosome production for the synthesis of magnetic particles for use in future commercial and medical applications. Here, we review the current information on the biology of MTB and apply, for the first time, a genome mining strategy on these microorganisms to search for secondary metabolite synthesis genes. More specifically, we discovered that the genome of the cultured MTB Magnetovibrio blakemorei, among other MTB, contains several metabolic pathways for the synthesis of secondary metabolites and other compounds, thereby raising the possibility of the co-production of new bioactive molecules along with magnetosomes by this species.
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209
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Rahn-Lee L, Byrne ME, Zhang M, Le Sage D, Glenn DR, Milbourne T, Walsworth RL, Vali H, Komeili A. A genetic strategy for probing the functional diversity of magnetosome formation. PLoS Genet 2015; 11:e1004811. [PMID: 25569806 PMCID: PMC4287615 DOI: 10.1371/journal.pgen.1004811] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 10/07/2014] [Indexed: 11/18/2022] Open
Abstract
Model genetic systems are invaluable, but limit us to understanding only a few organisms in detail, missing the variations in biological processes that are performed by related organisms. One such diverse process is the formation of magnetosome organelles by magnetotactic bacteria. Studies of model magnetotactic α-proteobacteria have demonstrated that magnetosomes are cubo-octahedral magnetite crystals that are synthesized within pre-existing membrane compartments derived from the inner membrane and orchestrated by a specific set of genes encoded within a genomic island. However, this model cannot explain all magnetosome formation, which is phenotypically and genetically diverse. For example, Desulfovibrio magneticus RS-1, a δ-proteobacterium for which we lack genetic tools, produces tooth-shaped magnetite crystals that may or may not be encased by a membrane with a magnetosome gene island that diverges significantly from those of the α-proteobacteria. To probe the functional diversity of magnetosome formation, we used modern sequencing technology to identify hits in RS-1 mutated with UV or chemical mutagens. We isolated and characterized mutant alleles of 10 magnetosome genes in RS-1, 7 of which are not found in the α-proteobacterial models. These findings have implications for our understanding of magnetosome formation in general and demonstrate the feasibility of applying a modern genetic approach to an organism for which classic genetic tools are not available.
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Affiliation(s)
- Lilah Rahn-Lee
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, California, United States of America
| | - Meghan E. Byrne
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, California, United States of America
| | - Manjing Zhang
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, California, United States of America
| | - David Le Sage
- Department of Physics, Harvard University, Cambridge, Massachusetts, United States of America
- Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, United States of America
| | - David R. Glenn
- Department of Physics, Harvard University, Cambridge, Massachusetts, United States of America
- Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, United States of America
- Center for Brain Science, Harvard University, Cambridge, Massachusetts, United States of America
| | - Timothy Milbourne
- Department of Physics, Harvard University, Cambridge, Massachusetts, United States of America
| | - Ronald L. Walsworth
- Department of Physics, Harvard University, Cambridge, Massachusetts, United States of America
- Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, United States of America
- Center for Brain Science, Harvard University, Cambridge, Massachusetts, United States of America
| | - Hojatollah Vali
- Facility for Electron Microscopy Research, McGill University, Montreal, Quebec, Canada
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada
- Department of Earth and Planetary Sciences, McGill University, Montreal, Quebec, Canada
| | - Arash Komeili
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, California, United States of America
- * E-mail:
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210
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Taoka A, Kondo J, Oestreicher Z, Fukumori Y. Characterization of uncultured giant rod-shaped magnetotactic Gammaproteobacteria from a freshwater pond in Kanazawa, Japan. Microbiology (Reading) 2014; 160:2226-2234. [DOI: 10.1099/mic.0.078717-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Magnetotactic bacteria (MTB) are widespread aquatic bacteria, and are a phylogenetically, physiologically and morphologically heterogeneous group, but they all have the ability to orientate and move along the geomagnetic field using intracellular magnetic organelles called magnetosomes. Isolation and cultivation of novel MTB are necessary for a comprehensive understanding of magnetosome formation and function in divergent MTB. In this study, we enriched a giant rod-shaped magnetotactic bacterium (strain GRS-1) from a freshwater pond in Kanazawa, Japan. Cells of strain GRS-1 were unusually large (~13×~8 µm). They swam in a helical trajectory towards the south pole of a bar magnet by means of a polar bundle of flagella. Another striking feature of GRS-1 was the presence of two distinct intracellular biomineralized structures: large electron-dense granules composed of calcium and long chains of magnetosomes that surround the large calcium granules. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that this strain belongs to the Gammaproteobacteria and represents a new genus of MTB.
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Affiliation(s)
- Azuma Taoka
- Bio-AFM Frontier Research Center, College of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa, Japan
- School of Natural System, College of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa, Japan
| | - Junya Kondo
- Department of Life Science, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma-machi, Kanazawa, Japan
| | - Zachery Oestreicher
- School of Natural System, College of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa, Japan
| | - Yoshihiro Fukumori
- Bio-AFM Frontier Research Center, College of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa, Japan
- School of Natural System, College of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa, Japan
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211
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Kolinko S, Richter M, Glöckner FO, Brachmann A, Schüler D. Single-cell genomics reveals potential for magnetite and greigite biomineralization in an uncultivated multicellular magnetotactic prokaryote. ENVIRONMENTAL MICROBIOLOGY REPORTS 2014; 6:524-531. [PMID: 25079475 DOI: 10.1111/1758-2229.12198] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 07/25/2014] [Indexed: 06/03/2023]
Abstract
For magnetic orientation, magnetotactic bacteria biosynthesize magnetosomes, which consist of membrane-enveloped magnetic nanocrystals of either magnetite (Fe3 O4 ) or greigite (Fe3 S4 ). While magnetite formation is increasingly well understood, much less is known about the genetic control of greigite biomineralization. Recently, two related yet distinct sets of magnetosome genes were discovered in a cultivated magnetotactic deltaproteobacterium capable of synthesizing either magnetite or greigite, or both minerals. This led to the conclusion that greigite and magnetite magnetosomes are synthesized by separate biomineralization pathways. Although magnetosomes of both mineral types co-occurred in uncultured multicellular magnetotactic prokaryotes (MMPs), so far only one type of magnetosome genes could be identified in the available genome data. The MMP Candidatus Magnetomorum strain HK-1 from coastal tidal sand flats of the North Sea (Germany) was analysed by a targeted single-cell approach. The draft genome assembly resulted in a size of 14.3 Mb and an estimated completeness of 95%. In addition to genomic features consistent with a sulfate-reducing lifestyle, we identified numerous genes putatively involved in magnetosome biosynthesis. Remarkably, most mam orthologues were present in two paralogous copies with highest similarity to either magnetite or greigite type magnetosome genes, supporting the ability to synthesize magnetite and greigite magnetosomes.
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Affiliation(s)
- Sebastian Kolinko
- Ludwig-Maximilians-Universität Munich, Microbiology, Großhaderner Str. 2-4, 82152, Planegg-Martinsried, Germany
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212
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Magnetic properties of uncultivated magnetotactic bacteria and their contribution to a stratified estuary iron cycle. Nat Commun 2014; 5:4797. [DOI: 10.1038/ncomms5797] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 07/25/2014] [Indexed: 11/08/2022] Open
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213
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Stanley S. Biological nanoparticles and their influence on organisms. Curr Opin Biotechnol 2014; 28:69-74. [DOI: 10.1016/j.copbio.2013.11.014] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 11/16/2013] [Accepted: 11/30/2013] [Indexed: 12/31/2022]
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214
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Ragon M, Benzerara K, Moreira D, Tavera R, López-García P. 16S rDNA-based analysis reveals cosmopolitan occurrence but limited diversity of two cyanobacterial lineages with contrasted patterns of intracellular carbonate mineralization. Front Microbiol 2014; 5:331. [PMID: 25071744 PMCID: PMC4085569 DOI: 10.3389/fmicb.2014.00331] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Accepted: 06/16/2014] [Indexed: 11/13/2022] Open
Abstract
Cyanobacteria are mainly thought to induce carbonate precipitation extracellularly via their photosynthetic activity combined with the nucleation potential of exopolymeric substances. The discovery in microbialites of the alkaline lake Alchichica (Mexico) of Candidatus Gloeomargarita lithophora, a cyanobacterium forming large amounts of intracellular Mg-Ca-Sr-Ba carbonate spherules, showed that intracellular biomineralization in cyanobacteria is also possible. A second cyanobacterium isolated from the same environment, Candidatus Synechococcus calcipolaris G9, has been recently shown to also form intracellular calcium carbonates at the cell poles, a capability shared by all cultured species of the Thermosynechococcus clade, to which it belongs. To explore the diversity of these two distant cyanobacterial lineages representing two different patterns of intracellular calcification, we designed specific primers against their 16S rRNA genes and looked for their occurrence in a wide variety of samples. We identified the presence of members of the Gloeomargarita and Thermosynechococcus/S. calcipolaris lineages in microbialites collected from Lake Alchichica and three other neighboring Mexican lakes. The two clades also occurred in karstic areas and in some thermophilic or hypersaline microbial mats collected in South America and/or Southern Europe. Surprisingly, the within-group diversity in the two clades was low, especially within the S. calcipolaris clade, with all 16S rRNA gene sequences retrieved sharing more than 97% identity. This suggests that these clades are composed of a limited number of operational taxonomic units (OTUs) with cosmopolitan distribution. Moreover, scanning electron microscopy coupled with energy dispersive x-ray spectrometry showed the presence of intracellularly calcifying Gloeomargarita-like cyanobacteria in fresh samples where this clade was relatively abundant, suggesting that these cyanobacteria do precipitate carbonates intracellularly under natural conditions.
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Affiliation(s)
- Marie Ragon
- Institut de Minéralogie, de Physique des Matériaux, et de Cosmochimie, Sorbonne Universités - UPMC Univ Paris 06, CNRS UMR 7590, MNHN, IRD UMR 206 Paris, France ; Unité d'Ecologie, Systématique et Evolution, Centre National de la Recherche Scientifique CNRS UMR8079, Université Paris-Sud Orsay, France
| | - Karim Benzerara
- Institut de Minéralogie, de Physique des Matériaux, et de Cosmochimie, Sorbonne Universités - UPMC Univ Paris 06, CNRS UMR 7590, MNHN, IRD UMR 206 Paris, France
| | - David Moreira
- Unité d'Ecologie, Systématique et Evolution, Centre National de la Recherche Scientifique CNRS UMR8079, Université Paris-Sud Orsay, France
| | - Rosaluz Tavera
- Departamento de Ecología y Recursos Naturales, Universidad Nacional Autónoma de México DF Mexico, Mexico
| | - Purificación López-García
- Unité d'Ecologie, Systématique et Evolution, Centre National de la Recherche Scientifique CNRS UMR8079, Université Paris-Sud Orsay, France
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215
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Körnig A, Winklhofer M, Baumgartner J, Gonzalez TP, Fratzl P, Faivre D. Magnetite Crystal Orientation in Magnetosome Chains. ADVANCED FUNCTIONAL MATERIALS 2014; 24:3926-3932. [PMID: 25866495 PMCID: PMC4384753 DOI: 10.1002/adfm.201303737] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 01/22/2014] [Indexed: 05/20/2023]
Abstract
One-dimensional magnetic nanostructures have magnetic properties superior to non-organized materials due to strong uniaxial shape anisotropy. Magnetosome chains in magnetotactic bacteria represent a biological paradigm of such magnet, where magnetite crystals synthesized in organelles called magnetosomes are arranged into linear chains. Two-dimensional synchrotron X-ray diffraction (XRD) is applied to cells of magnetotactic bacteria that are pre-aligned with a magnetic field to determine the crystallographic orientation of magnetosomes relative to the chain axis. The obtained pole figure patterns reveal a [111] fiber texture along the chain direction for magnetospirilla strains MSR-1 and AMB-1, whereas a [100] fiber texture is measured for Desulfovibrio magneticus strain RS-1. The [100] axis appears energetically unfavorable because it represents a magnetic hard axis in magnetite, but can be turned into an effective easy axis by particle elongation along [100] for aspect ratios higher than 1.25, consistent with aspect ratios in RS-1 magnetosomes determined earlier. The pronounced fiber textures can be explained either by a strain-specific biological control on crystal orientation at the chain level or by physical alignment effects due to intra-chain magnetic interactions. In this case, biological control of the axis of elongation would be sufficient to influence the crystallographic texture of the magnetosome chain.
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Affiliation(s)
- André Körnig
- Department of Biomaterials, Max Planck Institute of Colloids and InterfacesScience Park Golm, 14424, Potsdam, Germany
| | - Michael Winklhofer
- Department of Earth and Environmental Sciences, Ludwig-Maximilians-University MunichTheresienstr. 41, 80333, Munich, Germany
| | - Jens Baumgartner
- Department of Biomaterials, Max Planck Institute of Colloids and InterfacesScience Park Golm, 14424, Potsdam, Germany
| | - Teresa Perez Gonzalez
- Department of Biomaterials, Max Planck Institute of Colloids and InterfacesScience Park Golm, 14424, Potsdam, Germany
| | - Peter Fratzl
- Department of Biomaterials, Max Planck Institute of Colloids and InterfacesScience Park Golm, 14424, Potsdam, Germany
| | - Damien Faivre
- Department of Biomaterials, Max Planck Institute of Colloids and InterfacesScience Park Golm, 14424, Potsdam, Germany
- E-mail:
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216
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Genomic insights into the uncultured genus 'Candidatus Magnetobacterium' in the phylum Nitrospirae. ISME JOURNAL 2014; 8:2463-77. [PMID: 24914800 DOI: 10.1038/ismej.2014.94] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Revised: 04/27/2014] [Accepted: 05/08/2014] [Indexed: 11/09/2022]
Abstract
Magnetotactic bacteria (MTB) of the genus 'Candidatus Magnetobacterium' in phylum Nitrospirae are of great interest because of the formation of hundreds of bullet-shaped magnetite magnetosomes in multiple bundles of chains per cell. These bacteria are worldwide distributed in aquatic environments and have important roles in the biogeochemical cycles of iron and sulfur. However, except for a few short genomic fragments, no genome data are available for this ecologically important genus, and little is known about their metabolic capacity owing to the lack of pure cultures. Here we report the first draft genome sequence of 3.42 Mb from an uncultivated strain tentatively named 'Ca. Magnetobacterium casensis' isolated from Lake Miyun, China. The genome sequence indicates an autotrophic lifestyle using the Wood-Ljungdahl pathway for CO2 fixation, which has not been described in any previously known MTB or Nitrospirae organisms. Pathways involved in the denitrification, sulfur oxidation and sulfate reduction have been predicted, indicating its considerable capacity for adaptation to variable geochemical conditions and roles in local biogeochemical cycles. Moreover, we have identified a complete magnetosome gene island containing mam, mad and a set of novel genes (named as man genes) putatively responsible for the formation of bullet-shaped magnetite magnetosomes and the arrangement of multiple magnetosome chains. This first comprehensive genomic analysis sheds light on the physiology, ecology and biomineralization of the poorly understood 'Ca. Magnetobacterium' genus.
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217
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Dufour SC, Laurich JR, Batstone RT, McCuaig B, Elliott A, Poduska KM. Magnetosome-containing bacteria living as symbionts of bivalves. ISME JOURNAL 2014; 8:2453-62. [PMID: 24914799 DOI: 10.1038/ismej.2014.93] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 05/06/2014] [Accepted: 05/08/2014] [Indexed: 11/10/2022]
Abstract
Bacteria containing magnetosomes (protein-bound nanoparticles of magnetite or greigite) are common to many sedimentary habitats, but have never been found before to live within another organism. Here, we show that octahedral inclusions in the extracellular symbionts of the marine bivalve Thyasira cf. gouldi contain iron, can exhibit magnetic contrast and are most likely magnetosomes. Based on 16S rRNA sequence analysis, T. cf. gouldi symbionts group with symbiotic and free-living sulfur-oxidizing, chemolithoautotrophic gammaproteobacteria, including the symbionts of other thyasirids. T. cf. gouldi symbionts occur both among the microvilli of gill epithelial cells and in sediments surrounding the bivalves, and are therefore facultative. We propose that free-living T. cf. gouldi symbionts use magnetotaxis as a means of locating the oxic-anoxic interface, an optimal microhabitat for chemolithoautotrophy. T. cf. gouldi could acquire their symbionts from near-burrow sediments (where oxic-anoxic interfaces likely develop due to the host's bioirrigating behavior) using their superextensile feet, which could transfer symbionts to gill surfaces upon retraction into the mantle cavity. Once associated with their host, however, symbionts need not maintain structures for magnetotaxis as the host makes oxygen and reduced sulfur available via bioirrigation and sulfur-mining behaviors. Indeed, we show that within the host, symbionts lose the integrity of their magnetosome chain (and possibly their flagellum). Symbionts are eventually endocytosed and digested in host epithelial cells, and magnetosomes accumulate in host cytoplasm. Both host and symbiont behaviors appear important to symbiosis establishment in thyasirids.
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Affiliation(s)
- Suzanne C Dufour
- Department of Biology, Memorial University of Newfoundland, St John's, Newfoundland A1B 3X9, Canada
| | - Jason R Laurich
- Department of Biology, Memorial University of Newfoundland, St John's, Newfoundland A1B 3X9, Canada
| | - Rebecca T Batstone
- Department of Biology, Memorial University of Newfoundland, St John's, Newfoundland A1B 3X9, Canada
| | - Bonita McCuaig
- Department of Biology, Memorial University of Newfoundland, St John's, Newfoundland A1B 3X9, Canada
| | - Alexander Elliott
- Department of Biology, Memorial University of Newfoundland, St John's, Newfoundland A1B 3X9, Canada
| | - Kristin M Poduska
- Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St John's, Newfoundland A1B 3X7, Canada
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218
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Arnoux P, Siponen MI, Lefèvre CT, Ginet N, Pignol D. Structure and evolution of the magnetochrome domains: no longer alone. Front Microbiol 2014; 5:117. [PMID: 24723915 PMCID: PMC3971196 DOI: 10.3389/fmicb.2014.00117] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 03/08/2014] [Indexed: 11/13/2022] Open
Abstract
Magnetotactic bacteria (MTB) can swim along Earth's magnetic field lines, thanks to the alignment of dedicated cytoplasmic organelles. These organelles, termed magnetosomes, are proteolipidic vesicles filled by a 35–120 nm crystal of either magnetite or greigite. The formation and alignment of magnetosomes are mediated by a group of specific genes, the mam genes, encoding the magnetosome-associated proteins. The whole process of magnetosome biogenesis can be divided into four sequential steps; (i) cytoplasmic membrane invagination, (ii) magnetosomes alignment, (iii) iron crystal nucleation and (iv) species-dependent mineral size and shape control. Since both magnetite and greigite are a mix of iron (III) and iron (II), iron redox state management within the magnetosome vesicle is a key issue. Recently, studies have started pointing out the importance of a MTB-specific c-type cytochrome domain found in several magnetosome-associated proteins (MamE, P, T, and X). This magnetochrome (MCR) domain is almost always found in tandem, and this tandem is either found alone (MamT), in combination with a PDZ domain (MamP), a domain of unknown function (MamX) or with a trypsin combined to one or two PDZ domains (MamE). By taking advantage of new genomic data available on MTB and a recent structural study of MamP, which helped define the MCR domain boundaries, we attempt to retrace the evolutionary history within and between the different MCR-containing proteins. We propose that the observed tandem repeat of MCR is the result of a convergent evolution and attempt to explain why this domain is rarely found alone.
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Affiliation(s)
- Pascal Arnoux
- Commissariat à l'énergie Atomique, DSV, IBEB, Lab Bioenerget Cellulaire Saint-Paul-lez-Durance, France ; Centre National de la Recherche Scientifique, UMR Biol Veget and Microbiol Environ Saint-Paul-lez-Durance, France ; Aix-Marseille Université Saint-Paul-lez-Durance, France
| | - Marina I Siponen
- Commissariat à l'énergie Atomique, DSV, IBEB, Lab Bioenerget Cellulaire Saint-Paul-lez-Durance, France ; Centre National de la Recherche Scientifique, UMR Biol Veget and Microbiol Environ Saint-Paul-lez-Durance, France ; Aix-Marseille Université Saint-Paul-lez-Durance, France
| | - Christopher T Lefèvre
- Commissariat à l'énergie Atomique, DSV, IBEB, Lab Bioenerget Cellulaire Saint-Paul-lez-Durance, France ; Centre National de la Recherche Scientifique, UMR Biol Veget and Microbiol Environ Saint-Paul-lez-Durance, France ; Aix-Marseille Université Saint-Paul-lez-Durance, France
| | - Nicolas Ginet
- Commissariat à l'énergie Atomique, DSV, IBEB, Lab Bioenerget Cellulaire Saint-Paul-lez-Durance, France ; Centre National de la Recherche Scientifique, UMR Biol Veget and Microbiol Environ Saint-Paul-lez-Durance, France ; Aix-Marseille Université Saint-Paul-lez-Durance, France
| | - David Pignol
- Commissariat à l'énergie Atomique, DSV, IBEB, Lab Bioenerget Cellulaire Saint-Paul-lez-Durance, France ; Centre National de la Recherche Scientifique, UMR Biol Veget and Microbiol Environ Saint-Paul-lez-Durance, France ; Aix-Marseille Université Saint-Paul-lez-Durance, France
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219
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Morillo V, Abreu F, Araujo AC, de Almeida LGP, Enrich-Prast A, Farina M, de Vasconcelos ATR, Bazylinski DA, Lins U. Isolation, cultivation and genomic analysis of magnetosome biomineralization genes of a new genus of South-seeking magnetotactic cocci within the Alphaproteobacteria. Front Microbiol 2014; 5:72. [PMID: 24616719 PMCID: PMC3934378 DOI: 10.3389/fmicb.2014.00072] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Accepted: 02/10/2014] [Indexed: 12/13/2022] Open
Abstract
Although magnetotactic bacteria (MTB) are ubiquitous in aquatic habitats, they are still considered fastidious microorganisms with regard to growth and cultivation with only a relatively low number of axenic cultures available to date. Here, we report the first axenic culture of an MTB isolated in the Southern Hemisphere (Itaipu Lagoon in Rio de Janeiro, Brazil). Cells of this new isolate are coccoid to ovoid in morphology and grow microaerophilically in semi-solid medium containing an oxygen concentration ([O2]) gradient either under chemoorganoheterotrophic or chemolithoautotrophic conditions. Each cell contains a single chain of approximately 10 elongated cuboctahedral magnetite (Fe3O4) magnetosomes. Phylogenetic analysis based on the 16S rRNA gene sequence shows that the coccoid MTB isolated in this study represents a new genus in the Alphaproteobacteria; the name Magnetofaba australis strain IT-1 is proposed. Preliminary genomic data obtained by pyrosequencing shows that M. australis strain IT-1 contains a genomic region with genes involved in biomineralization similar to those found in the most closely related magnetotactic cocci Magnetococcus marinus strain MC-1. However, organization of the magnetosome genes differs from M. marinus.
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Affiliation(s)
- Viviana Morillo
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil
| | - Fernanda Abreu
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil
| | - Ana C Araujo
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil
| | - Luiz G P de Almeida
- Laboratório Nacional de Computação Científica, Departamento de Matemática Aplicada e Computacional Petrópolis, Brazil
| | - Alex Enrich-Prast
- Instituto de Biologia, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil
| | - Marcos Farina
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil
| | - Ana T R de Vasconcelos
- Laboratório Nacional de Computação Científica, Departamento de Matemática Aplicada e Computacional Petrópolis, Brazil
| | - Dennis A Bazylinski
- School of Life Sciences, University of Nevada at Las Vegas Las Vegas, NV, USA
| | - Ulysses Lins
- Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil
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220
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Moisescu C, Ardelean II, Benning LG. The effect and role of environmental conditions on magnetosome synthesis. Front Microbiol 2014; 5:49. [PMID: 24575087 PMCID: PMC3920197 DOI: 10.3389/fmicb.2014.00049] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 01/23/2014] [Indexed: 12/14/2022] Open
Abstract
Magnetotactic bacteria (MTB) are considered the model species for the controlled biomineralization of magnetic Fe oxide (magnetite, Fe3O4) or Fe sulfide (greigite, Fe3S4) nanocrystals in living organisms. In MTB, magnetic minerals form as membrane-bound, single-magnetic domain crystals known as magnetosomes and the synthesis of magnetosomes by MTB is a highly controlled process at the genetic level. Magnetosome crystals reveal highest purity and highest quality magnetic properties and are therefore increasingly sought after as novel nanoparticulate biomaterials for industrial and medical applications. In addition, "magnetofossils," have been used as both past terrestrial and potential Martian life biosignature. However, until recently, the general belief was that the morphology of mature magnetite crystals formed by MTB was largely unaffected by environmental conditions. Here we review a series of studies that showed how changes in environmental factors such as temperature, pH, external Fe concentration, external magnetic fields, static or dynamic fluid conditions, and nutrient availability or concentrations can all affect the biomineralization of magnetite magnetosomes in MTB. The resulting variations in magnetic nanocrystals characteristics can have consequence both for their commercial value but also for their use as indicators for ancient life. In this paper we will review the recent findings regarding the influence of variable chemical and physical environmental control factors on the synthesis of magnetosome by MTB, and address the role of MTB in the global biogeochemical cycling of iron.
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Affiliation(s)
- Cristina Moisescu
- Department of Microbiology, Institute of Biology BucharestBucharest, Romania
| | - Ioan I. Ardelean
- Department of Microbiology, Institute of Biology BucharestBucharest, Romania
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221
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Pósfai M, Lefèvre CT, Trubitsyn D, Bazylinski DA, Frankel RB. Phylogenetic significance of composition and crystal morphology of magnetosome minerals. Front Microbiol 2013; 4:344. [PMID: 24324461 PMCID: PMC3840360 DOI: 10.3389/fmicb.2013.00344] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2013] [Accepted: 10/30/2013] [Indexed: 11/17/2022] Open
Abstract
Magnetotactic bacteria (MTB) biomineralize magnetosomes, nano-scale crystals of magnetite or greigite in membrane enclosures that comprise a permanent magnetic dipole in each cell. MTB control the mineral composition, habit, size, and crystallographic orientation of the magnetosomes, as well as their arrangement within the cell. Studies involving magnetosomes that contain mineral and biological phases require multidisciplinary efforts. Here we use crystallographic, genomic and phylogenetic perspectives to review the correlations between magnetosome mineral habits and the phylogenetic affiliations of MTB, and show that these correlations have important implications for the evolution of magnetosome synthesis, and thus magnetotaxis.
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Affiliation(s)
- Mihály Pósfai
- Department of Earth and Environmental Sciences, University of Pannonia Veszprém, Hungary
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222
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Lin W, Bazylinski DA, Xiao T, Wu LF, Pan Y. Life with compass: diversity and biogeography of magnetotactic bacteria. Environ Microbiol 2013; 16:2646-58. [PMID: 24148107 DOI: 10.1111/1462-2920.12313] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 10/12/2013] [Indexed: 11/29/2022]
Abstract
Magnetotactic bacteria (MTB) are unique in their ability to synthesize intracellular nano-sized minerals of magnetite and/or greigite magnetosomes for magnetic orientation. Thus, they provide an excellent model system to investigate mechanisms of biomineralization. MTB play important roles in bulk sedimentary magnetism and have numerous versatile applications in paleoenvironmental reconstructions, and biotechnological and biomedical fields. Significant progress has been made in recent years in describing the composition of MTB communities and distribution through innovative cultivation-dependent and -independent techniques. In this review, the most recent contributions to the field of diversity and biogeography of MTB are summarized and reviewed. Emphasis is on the novel insights into various factors/processes potentially affecting MTB community distribution. An understanding of the present-day biogeography of MTB, and the ruling parameters of their spatial distribution, will eventually help us predict MTB community shifts with environmental changes and assess their roles in global iron cycling.
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Affiliation(s)
- Wei Lin
- Biogeomagnetism Group, Paleomagnetism and Geochronology Laboratory, Key Laboratory of the Earth's Deep Interior, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, 100029, China; France-China Bio-Mineralization and Nano-Structures Laboratory, Chinese Academy of Sciences, Beijing, 100029, China
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