Phylogenetic analysis of a novel sulfate-reducing magnetic bacterium, RS-1, demonstrates its membership of the Î´-Proteobacteria

Kawaguchi, Ryuji; Burgess, J. Grant; Sakaguchi, Toshifumi; Takeyama, Haruko; Thornhill, Richard; Matsunaga, Tadashi

doi:10.1111/j.1574-6968.1995.tb07430.x

Cited by 31 publications

(26 citation statements)

References 29 publications

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“…Desulfovibrio magneticus RS-1 (figure 1b)-a dissimilatory sulphate-reducing bacterium belonging to the d-Proteobacteria class-produces unique irregular bullet-shaped BacMPs (figure 1d; Sakaguchi et al 1993Sakaguchi et al , 2002Kawaguchi et al 1995). The production of BacMPs within the RS-1 strain is substrate dependent, whereby RS-1 cells produced an average of six BacMPs per individual cell when fumarate was used as an electron acceptor, while almost no BacMPs were produced when sulphate was used.…”

Section: Diversity Of Magnetotactic Bacteriamentioning

confidence: 99%

“…This strategy allows isolation of non-motile and non-responsive or weakly responding magnetotactic bacteria, which cannot be isolated by magnetic force. Furthermore, systematic characterization of the RS-1 strain has also been examined (Sakaguchi et al 2002), whereby phylogenetic analysis based on 16S rDNA gene sequences revealed that RS-1 is a member of the genus Desulfovibrio (Kawaguchi et al 1995; figure 2). The RS-1 strain contains desulphoviridin, c-type cytochromes and, unlike other Desulfovibrio spp., possesses menaquinone MK-7(H 2 ) instead of MK-6 or MK-6(H 2 ).…”

Section: Diversity Of Magnetotactic Bacteriamentioning

confidence: 99%

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Formation of magnetite by bacteria and its application

Arakaki

Nakazawa

Nemoto

et al. 2008

J. R. Soc. Interface.

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220

176

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Magnetic particles offer high technological potential since they can be conveniently collected with an external magnetic field. Magnetotactic bacteria synthesize bacterial magnetic particles (BacMPs) with well-controlled size and morphology. BacMPs are individually covered with thin organic membrane, which confers high and even dispersion in aqueous solutions compared with artificial magnetites, making them ideal biotechnological materials. Recent molecular studies including genome sequence, mutagenesis, gene expression and proteome analyses indicated a number of genes and proteins which play important roles for BacMP biomineralization. Some of the genes and proteins identified from these studies have allowed us to express functional proteins efficiently onto BacMPs, through genetic engineering, permitting the preservation of the protein activity, leading to a simple preparation of functional protein-magnetic particle complexes. They were applicable to high-sensitivity immunoassay, drug screening and cell separation. Furthermore, fully automated single nucleotide polymorphism discrimination and DNA recovery systems have been developed to use these functionalized BacMPs. The nano-sized fine magnetic particles offer vast potential in new nano-techniques.

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Section: Diversity Of Magnetotactic Bacteriamentioning

confidence: 99%

Section: Diversity Of Magnetotactic Bacteriamentioning

confidence: 99%

Formation of magnetite by bacteria and its application

Arakaki

Nakazawa

Nemoto

et al. 2008

J. R. Soc. Interface.

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220

176

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“…Molecular analysis has shown that freshwater MMB are generally affiliated with the ␣-Proteobacteria (48)(49)(50). Exceptions are Desulfovibrio magneticus of the ␦-Proteobacteria (22) and M. bavaricum in the Nitrospira phylum (52). The phylogeny of GMB is unknown, with the exception of one uncultivated packet-forming GMB called the many-celled magnetotactic prokaryote (MMP), which has been identified as one of the ␦-Proteobacteria by fluorescent in situ hybridization (FISH) (13).…”

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confidence: 99%

Spatiotemporal Distribution of Marine Magnetotactic Bacteria in a Seasonally Stratified Coastal Salt Pond

Simmons

Sievert²,

Frankel

et al. 2004

Appl Environ Microbiol

182

219

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The occurrence and distribution of magnetotactic bacteria (MB) were studied as a function of the physical and chemical conditions in meromictic Salt Pond, Falmouth, Mass., throughout summer 2002. Three dominant MB morphotypes were observed to occur within the chemocline. Small microaerophilic magnetite-producing cocci were present at the top of the chemocline, while a greigite-producing packet-forming bacterium occurred at the base of the chemocline. The distributions of these groups displayed sharp changes in abundance over small length scales within the water column as well as strong seasonal fluctuations in population abundance. We identified a novel, greigite-producing rod in the sulfidic hypolimnion that was present in relatively constant abundance over the course of the season. This rod is the first MB that appears to belong to the ␥-Proteobacteria, which may suggest an iron-rather than sulfur-based respiratory metabolism. Its distribution and phylogenetic identity suggest that an alternative model for the ecological and physiological role of magnetotaxis is needed for greigite-producing MB.Magnetotactic bacteria (MB) are motile gram-negative bacteria whose directional swimming behavior is affected by the Earth's geomagnetic and external magnetic fields. They contain highly ordered intracellular chains of magnetic iron minerals, either magnetite (Fe 3 O 4 ), greigite (Fe 3 S 4 ) (33), or in one case, both (7). Magnetite MB (MMB) are found in both freshwater and marine environments, while greigite MB (GMB) appear to be unique to marine systems. Both MMB and GMB are present in salt marsh sediments, stratified salt ponds, estuarine basins in the Eastern coastal United States (5-7, 32, 33, 51), coastal marshes along the California coast (E. F. DeLong, personal communication), and other similar habitats worldwide, as well as deep-sea sediments (43). This widespread distribution of marine MB suggests that they are globally more abundant than freshwater MB.All known MB share the following characteristics: motility by means of flagella, negative tactic responses to atmospheric concentrations of oxygen, optimal growth under microaerophilic or anaerobic conditions, and a respiratory metabolism (51). MB are typically found at or below the oxycline in sediments and water columns and can reach significant population densities: the freshwater MMB "Magnetotacticum bavaricum" (proposed name) can reach 7 ϫ 10 5 cells per cm 3 at the oxycline in freshwater sediments (48). Many, if not most, groups of MB that have been observed in the environment have not been grown in pure culture in the laboratory. Fewer than 10 strains are available in pure culture, and most of those are magnetiteproducing ␣-Proteobacteria of the genus Magnetospirillum from freshwater environments. A few strains of marine MMB are available in culture (3,45,51). These strains are all microaerophiles when growing on O 2 , and some can grow anaerobically on N 2 O (3). All are capable of oxidizing but not reducing inorganic sulfur compounds, with the exceptio...

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“…RS-1 (RS-1) is an ideal system to investigate the range of magnetite biomineralization mechanisms used by MB, because it is the only axenically cultured magnetotactic bacterium outside of the α-Proteobacteria and forms crystals that are irregular or bullet-shaped (11)(12)(13). Recently, the genome of RS-1 was sequenced and found to contain a region resembling a highly edited version of the MAI (14,15).…”

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confidence: 99%

Desulfovibrio magneticus RS-1 contains an iron- and phosphorus-rich organelle distinct from its bullet-shaped magnetosomes

Byrne

Ball²,

Guerquin‐Kern³

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

107

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Intracellular magnetite crystal formation by magnetotactic bacteria has emerged as a powerful model for investigating the cellular and molecular mechanisms of biomineralization, a process common to all branches of life. Although magnetotactic bacteria are phylogenetically diverse and their crystals morphologically diverse, studies to date have focused on a few, closely related species with similar crystal habits. Here, we investigate the process of magnetite biomineralization in Desulfovibrio magneticus sp. RS-1, the only reported species of cultured magnetotactic bacteria that is outside of the α-Proteobacteria and that forms bulletshaped crystals. Using a variety of high-resolution imaging and analytical tools, we show that RS-1 cells form amorphous, noncrystalline granules containing iron and phosphorus before forming magnetite crystals. Using NanoSIMS (dynamic secondary ion mass spectroscopy), we show that the iron-phosphorus granules and the magnetite crystals are likely formed through separate cellular processes. Analysis of the cellular ultrastructure of RS-1 using cryo-ultramicrotomy, cryo-electron tomography, and tomography of ultrathin sections reveals that the magnetite crystals are not surrounded by membranes but that the iron-phosphorus granules are surrounded by membranous compartments. The varied cellular paths for the formation of these two minerals lead us to suggest that the iron-phosphorus granules constitute a distinct bacterial organelle.bacterial organelle | biomineralization | magnetotactic bacteria | dynamic secondary ion mass spectroscopy | magnetite B iomineralization, the biologically controlled transformation of inorganic compounds into highly-ordered structures, is performed by organisms in all branches of life, from bacteria to humans. Because biogenic minerals often have superior properties to their chemically synthesized counterparts, understanding biomineralization is important to fields as diverse as inorganic materials synthesis and medicine (1, 2). Among the numerous organisms capable of biomineralization, magnetotactic bacteria (MB), a group of microbes that form intracellular chains of magnetic minerals including magnetite and greigite, have become powerful models for studying biomineralization because of their relatively fast growth rate and genetic tractability (3).Investigation of the cellular ultrastructure of MB has shown that the magnetite crystals are formed within membranous intracellular compartments called magnetosomes, which are present before the formation of magnetite (4, 5). Other studies have shown that when magnetite formation is induced by decreasing oxygen levels or adding iron to iron-deprived cells, multiple crystals in the chain nucleate simultaneously (5, 6). These insights into the kinetics of magnetite biomineralization have been complemented by molecular studies. A genomic island called the magnetosome island (MAI) has been found in all MB studied to date. Loss of the MAI results in an absence of magnetosome membranes and magnetite crystals, and gene...

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Phylogenetic analysis of a novel sulfate-reducing magnetic bacterium, RS-1, demonstrates its membership of the Î´-Proteobacteria

Cited by 31 publications

References 29 publications

Formation of magnetite by bacteria and its application

Formation of magnetite by bacteria and its application

Spatiotemporal Distribution of Marine Magnetotactic Bacteria in a Seasonally Stratified Coastal Salt Pond

Desulfovibrio magneticus RS-1 contains an iron- and phosphorus-rich organelle distinct from its bullet-shaped magnetosomes

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