New magnet‐sensitive structures in bacterial and archaeal cells

Vainshtein, Mikhail; Suzina, N. E.; Kudryashova, E. B.; Ariskina, Elena V.

doi:10.1016/s0248-4900(02)01179-6

Cited by 43 publications

(37 citation statements)

References 24 publications

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“…Vainshtein et al (57) identified magnet-sensitive particles in Ectothiorhodospira shaposhnikovii which were rich in Fe but did not contain sulfur. In a separate study, Vainshtein et al (56) found magnet-sensitive inclusions of various types in prokaryotic cells of diverse phylogenies when they were grown in medium containing 1 mM iron, suggesting some kind of detoxification function. The inclusions were not ordered crystals and incorporated various other unspecified organic compounds.…”

Section: Discussionmentioning

confidence: 98%

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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Section: Discussionmentioning

confidence: 98%

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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“…[4][5][6][7]9,[32][33][34][35][36][37][38][39][40] However, as already mentioned, for the first time BMNPs have been revealed in MTB that are characterized by the ability to "taxi" or navigate under a geomagnetic field. That is why historically the idea of magnetotaxis was transformed into an 59 dolphins, whales, 60 and humans.…”

Section: Physicochemical Properties Of Bmnps Bmnps In Mtb Magnetosomesmentioning

confidence: 99%

“…As a rule, BMNPs in multicellular organisms vary in shape, size, and other properties, and are not enclosed in magnetosome vesicles. 39,68 In archaea, in which the surroundings of BMNPs have been adequately investigated, magnet-sensitive inclusions have been found, which are surrounded by a homogeneous matrix with organic (mainly protein) components. 39 The absence of vesicles or a similar organic matrix consisting of protein filaments around magnetite BMNPs 68 has also been observed in human cells.…”

Section: Physicochemical Properties Of Bmnps Bmnps In Mtb Magnetosomesmentioning

confidence: 99%

“…23,115 That is why it is possible that the favorable chemical surroundings for BMNP growth are provided inside the organic matrix or another type of organic material (Figure 6), as is observed in non-MTB with BMNPs. 39 Not all nonmagnetotactic organisms have a homologue of the MamK protein. 116 This is consistent with the experimental observation of BMNPs not arranged in chains.…”

mentioning

confidence: 99%

“…116 This is consistent with the experimental observation of BMNPs not arranged in chains. 39 However, BMNP chains can form even without MamK. Biogenic and artificial magnetite NPs can arrange in chains also as a result of magnetic dipole-dipole interaction ( Figure 7).…”

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confidence: 99%

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Physiological origin of biogenic magnetic nanoparticles in health and disease: from bacteria to humans

Gorobets¹,

Gorobets²,

Koralewski³

2017

IJN

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The discovery of biogenic magnetic nanoparticles (BMNPs) in the human brain gives a strong impulse to study and understand their origin. Although knowledge of the subject is increasing continuously, much remains to be done for further development to help our society fight a number of pathologies related to BMNPs. This review provides an insight into the puzzle of the physiological origin of BMNPs in organisms of all three domains of life: prokaryotes, archaea, and eukaryotes, including humans. Predictions based on comparative genomic studies are presented along with experimental data obtained by physical methods. State-of-the-art understanding of the genetic control of biomineralization of BMNPs and their properties are discussed in detail. We present data on the differences in BMNP levels in health and disease (cancer, neurodegenerative disorders, and atherosclerosis), and discuss the existing hypotheses on the biological functions of BMNPs, with special attention paid to the role of the ferritin core and apoferritin.

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Archaeal Cells

Klingl

Flechsler

Heimerl

et al. 2013

Encyclopedia of Life Sciences

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At a first glance, Archaea are structurally seen quite similar to Bacteria, and for a long time they were named ‘Archaebacteria’. They can form cocci, rods, spirals or irregular shaped cells and are equally sized as Bacteria. Together they are referred to as ‘Prokaryotes’ because neither Archaea nor Bacteria have a nucleus. Although this term indeed might be helpful in habitual language use, it does not refer to a phylogenetic group. In fact, transcription and translation machineries of Archaea have much more in common with eukaryotic cells than with Bacteria. In addition, there are many features that remain characteristic for Archaea, given by the fact that many representatives live and thrive under extreme environmental conditions. In the review, the authors give a comprehensive overview about the stunning diversity of structural features in archaeal cell envelopes, membranes and cell appendages. Key Concepts: By application of recently developed PCR techniques, Archaea can be found in almost every habitat and sometimes are even more abundant than bacteria. Archaea show special adaptations to their sometimes extreme environments, like caldarchaeols, which are more stable at high temperatures. Like Bacteria, Archaea are also surrounded by a lipid bilayer, but in the latter case the lipid moiety consists of C 5 ‐isoprenoid units that are coupled to glycerol via ether bonds at (sn)‐2,3 positions of the glycerol. Cell walls can be as simple as a proteinaceous surface layer or as complicated as in some methanogens with multiple layers, additional sheats enclosing several cells and even more complex cell wall compounds. Archaea exhibit a broad variety in cell appendages that are different to bacterial ones in fine structure, composition, biosynthesis and anchorage in the cell.

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New magnet‐sensitive structures in bacterial and archaeal cells

Cited by 43 publications

References 24 publications

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

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

Physiological origin of biogenic magnetic nanoparticles in health and disease: from bacteria to humans

Archaeal Cells

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