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Microbiological Research Oct 2017Bacterial magnetosome, synthetized by magnetosome-producing microorganisms including magnetotactic bacteria (MTB) and some non-magnetotactic bacteria (Non-MTB), is a new... (Review)
Review
Bacterial magnetosome, synthetized by magnetosome-producing microorganisms including magnetotactic bacteria (MTB) and some non-magnetotactic bacteria (Non-MTB), is a new type of material comprising magnetic nanocrystals surrounded by a phospholipid bilayer. Because of the special properties such as single magnetic domain, excellent biocompatibility and surface modification, bacterial magnetosome has become an increasingly attractive for researchers in biology, medicine, paleomagnetism, geology and environmental science. This review briefly describes the general feature of magnetosome-producing microorganisms. This article also highlights recent advances in the understanding of the biochemical and magnetic characteristics of bacterial magnetosome, as well as the magnetosome formation mechanism including iron ions uptake, magnetosome membrane formation, biomineralization and magnetosome chain assembly. Finally, this review presents the potential applications of bacterial magnetosome in biomedicine, wastewater treatment, and the significance of mineralization of magnetosome in biology and geology.
Topics: Cell Membrane; Ferrosoferric Oxide; Iron; Magnetic Fields; Magnetosomes; Magnetospirillum; Sulfides
PubMed: 28754204
DOI: 10.1016/j.micres.2017.06.005 -
Nature Communications Sep 2019Spin wave logic circuits using quantum oscillations of spins (magnons) as carriers of information have been proposed for next generation computing with reduced energy...
Spin wave logic circuits using quantum oscillations of spins (magnons) as carriers of information have been proposed for next generation computing with reduced energy demands and the benefit of easy parallelization. Current realizations of magnonic devices have micrometer sized patterns. Here we demonstrate the feasibility of biogenic nanoparticle chains as the first step to truly nanoscale magnonics at room temperature. Our measurements on magnetosome chains (ca 12 magnetite crystals with 35 nm particle size each), combined with micromagnetic simulations, show that the topology of the magnon bands, namely anisotropy, band deformation, and band gaps are determined by local arrangement and orientation of particles, which in turn depends on the genotype of the bacteria. Our biomagnonic approach offers the exciting prospect of genetically engineering magnonic quantum states in nanoconfined geometries. By connecting mutants of magnetotactic bacteria with different arrangements of magnetite crystals, novel architectures for magnonic computing may be (self-) assembled.
Topics: Anisotropy; Computer Simulation; Crystallization; Genotype; Magnetics; Magnetosomes; Magnetospirillum; Mutation; Nanoparticles; Particle Size; Quantum Theory; Spin Labels
PubMed: 31554798
DOI: 10.1038/s41467-019-12219-0 -
Marine Drugs Jan 2015Magnetotactic bacteria (MTB) produce intracellular organelles called magnetosomes which are magnetic nanoparticles composed of magnetite (Fe3O4) or greigite (Fe3S4)... (Review)
Review
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.
Topics: Biological Products; Magnetic Phenomena; Magnetosomes; Rhodospirillaceae
PubMed: 25603340
DOI: 10.3390/md13010389 -
Microbiological Reviews Jun 1978
Review
Topics: Bacteriochlorophylls; Bacteriocins; Bacteriophages; Biological Evolution; Conjugation, Genetic; DNA, Bacterial; Electron Transport; Mutation; Plasmids; Rhodospirillaceae; Species Specificity; Transformation, Bacterial
PubMed: 353480
DOI: 10.1128/mr.42.2.357-384.1978 -
BMC Genomics May 2019Magnetotactic bacteria (MTB) are ubiquitous in natural aquatic environments. MTB can produce intracellular magnetic particles, navigate along geomagnetic field, and...
BACKGROUND
Magnetotactic bacteria (MTB) are ubiquitous in natural aquatic environments. MTB can produce intracellular magnetic particles, navigate along geomagnetic field, and respond to light. However, the potential mechanism by which MTB respond to illumination and their evolutionary relationship with photosynthetic bacteria remain elusive.
RESULTS
We utilized genomes of the well-sequenced genus Magnetospirillum, including the newly sequenced MTB strain Magnetospirillum sp. XM-1 to perform a comprehensive genomic comparison with phototrophic bacteria within the family Rhodospirillaceae regarding the illumination response mechanism. First, photoreceptor genes were identified in the genomes of both MTB and phototrophic bacteria in the Rhodospirillaceae family, but no photosynthesis genes were found in the MTB genomes. Most of the photoreceptor genes in the MTB genomes from this family encode phytochrome-domain photoreceptors that likely induce red/far-red light phototaxis. Second, illumination also causes damage within the cell, and in Rhodospirillaceae, both MTB and phototrophic bacteria possess complex but similar sets of response and repair genes, such as oxidative stress response, iron homeostasis and DNA repair system genes. Lastly, phylogenomic analysis showed that MTB cluster closely with phototrophic bacteria in this family. One photoheterotrophic genus, Phaeospirillum, clustered within and displays high genomic similarity with Magnetospirillum. Moreover, the phylogenetic tree topologies of magnetosome synthesis genes in MTB and photosynthesis genes in phototrophic bacteria from the Rhodospirillaceae family were reasonably congruent with the phylogenomic tree, suggesting that these two traits were most likely vertically transferred during the evolution of their lineages.
CONCLUSION
Our new genomic data indicate that MTB and phototrophic bacteria within the family Rhodospirillaceae possess diversified photoreceptors that may be responsible for phototaxis. Their genomes also contain comprehensive stress response genes to mediate the negative effects caused by illumination. Based on phylogenetic studies, most of MTB and phototrophic bacteria in the Rhodospirillaceae family evolved vertically with magnetosome synthesis and photosynthesis genes. The ancestor of Rhodospirillaceae was likely a magnetotactic phototrophic bacteria, however, gain or loss of magnetotaxis and phototrophic abilities might have occurred during the evolution of ancestral Rhodospirillaceae lineages.
Topics: Bacterial Proteins; Biological Evolution; Genome, Bacterial; Genomics; Light; Magnetosomes; Phylogeny; Rhodospirillaceae
PubMed: 31117953
DOI: 10.1186/s12864-019-5751-9 -
ACS Applied Materials & Interfaces May 2022Biocatalysis in flow reactor systems is of increasing importance for the transformation of the chemical industry. However, the necessary immobilization of biocatalysts...
Biocatalysis in flow reactor systems is of increasing importance for the transformation of the chemical industry. However, the necessary immobilization of biocatalysts remains a challenge. We here demonstrate that biogenic magnetic nanoparticles, so-called magnetosomes, represent an attractive alternative for the development of nanoscale particle formulations to enable high and stable conversion rates in biocatalytic flow processes. In addition to their intriguing material characteristics, such as high crystallinity, stable magnetic moments, and narrow particle size distribution, magnetosomes offer the unbeatable advantage over chemically synthesized nanoparticles that foreign protein "cargo" can be immobilized on the enveloping membrane via genetic engineering and thus, stably presented on the particle surface. To exploit these advantages, we develop a modular connector system in which abundant magnetosome membrane anchors are genetically fused with SpyCatcher coupling groups, allowing efficient covalent coupling with complementary SpyTag-functionalized proteins. The versatility of this approach is demonstrated by immobilizing a dimeric phenolic acid decarboxylase to SpyCatcher magnetosomes. The functionalized magnetosomes outperform similarly functionalized commercial particles by exhibiting stable substrate conversion during a 60 h period, with an average space-time yield of 49.2 mmol L h. Overall, our results demonstrate that SpyCatcher magnetosomes significantly expand the genetic toolbox for particle surface functionalization and increase their application potential as nano-biocatalysts.
Topics: Biocatalysis; Genetic Engineering; Magnetosomes; Magnetospirillum; Nanoparticles
PubMed: 35508355
DOI: 10.1021/acsami.2c03337 -
Emerging Infectious Diseases Oct 2022We isolated Haematospirillum jordaniae from a positive blood culture from a 57-year-old man in Slovenia who had bacteremia and bullous cellulitis of lower extremities....
We isolated Haematospirillum jordaniae from a positive blood culture from a 57-year-old man in Slovenia who had bacteremia and bullous cellulitis of lower extremities. The infection was successfully treated with ciprofloxacin. Our findings signal the need for increased awareness about the clinical course of H. jordaniae and its potential effects as a human pathogen.
Topics: Bacteremia; Cellulitis; Ciprofloxacin; Humans; Male; Middle Aged; Rhodospirillaceae
PubMed: 36148990
DOI: 10.3201/eid2810.220326 -
The Journal of Physical Chemistry. B Apr 2022Defining chemical properties of intracellular organelles is necessary to determine their function(s) as well as understand and mimic the reactions they host. However,...
Defining chemical properties of intracellular organelles is necessary to determine their function(s) as well as understand and mimic the reactions they host. However, the small size of bacterial and archaeal microorganisms often prevents defining local intracellular chemical conditions in a similar way to what has been established for eukaryotic organelles. This work proposes to use magnetite (FeO) nanocrystals contained in magnetosome organelles of magnetotactic bacteria as reporters of elemental composition, pH, and redox potential of a hypothetical environment at the site of formation of intracellular magnetite. This methodology requires combining recent single-cell mass spectrometry measurements together with elemental composition of magnetite in trace and minor elements. It enables a quantitative characterization of chemical disequilibria of 30 chemical elements between the intracellular and external media of magnetotactic bacteria, revealing strong transfers of elements with active influx or efflux processes that translate into elemental accumulation (Mo, Se, and Sn) or depletion (Sr and Bi) in the bacterial internal medium of up to seven orders of magnitude relative to the extracellular medium. Using this concept, we show that chemical conditions in magnetosomes are compatible with a pH of 7.5-9.5 and a redox potential of -0.25 to -0.6 V.
Topics: Bacteria; Ferrosoferric Oxide; Gram-Negative Bacteria; Magnetosomes; Magnetospirillum
PubMed: 35362974
DOI: 10.1021/acs.jpcb.2c00752 -
Infection and Immunity May 1977The lipopolysaccharides and free lipid A from several strains of Rhodospirillaceae were assayed comparatively with those of Enterobacteriaceae in a number of biological...
The lipopolysaccharides and free lipid A from several strains of Rhodospirillaceae were assayed comparatively with those of Enterobacteriaceae in a number of biological tests. Free lipid A's from Rhodopseudomonas gelatinosa and Rhodospirillum tenue exhibited strong serological cross-reactions with each other and with free lipid A from Salmonella. Lipid A's from Rhodopseudomonas viridis and Rhodopseudomonas palustris, although cross-reacting with each other, did not do so with either the lipid A of R. gelatinosa or R. tenue or with that of Salmonella. The presence or absence of the above cross-reactions agreed with corresponding similarities or differences in the chemical structure of the lipid A preparations. The lipopolysaccharide of R. gelatinosa was highly toxic for adrenalectomized mice and pyrogenic for rabbits; however, it exhibited no anti-complementary activity. The activity of the R. tenue lipopolysaccharide was very low in both the lethality and pyrogenicity tests. Its corresponding free lipid A also exhibited low pyrogenic activity; however, its lethal toxicity for adrenalectomized mice was considerably higher than that of the intact parent lipopolysaccharide. Both intact lipopolysaccharide and, unexpectedly, the free lipid A exhibited no anti-complementary activity. The lipopolysaccharides of R. viridis and R. palustris were virtually nontoxic for mice and nonpyrogenic for rabbits. Both lipopolysaccharides were highly potent in their interaction with complement. They therefore represent the first example of nontoxic lipopolysaccharides exhibiting high anti-complementary activity.
Topics: Animals; Complement System Proteins; Cross Reactions; Hemagglutination Inhibition Tests; Immune Sera; Lethal Dose 50; Lipid A; Lipopolysaccharides; Pyrogens; Rabbits; Rhodospirillaceae; Salmonella
PubMed: 558961
DOI: 10.1128/iai.16.2.407-412.1977 -
FEMS Microbiology Reviews Jul 2008The ability of magnetotactic bacteria (MTB) to orient in magnetic fields is based on the synthesis of magnetosomes, which are unique prokaryotic organelles comprising... (Review)
Review
The ability of magnetotactic bacteria (MTB) to orient in magnetic fields is based on the synthesis of magnetosomes, which are unique prokaryotic organelles comprising membrane-enveloped, nano-sized crystals of a magnetic iron mineral that are aligned in well-ordered intracellular chains. Magnetosome crystals have species-specific morphologies, sizes, and arrangements. The magnetosome membrane, which originates from the cytoplasmic membrane by invagination, represents a distinct subcellular compartment and has a unique biochemical composition. The roughly 20 magnetosome-specific proteins have functions in vesicle formation, magnetosomal iron transport, and the control of crystallization and intracellular arrangement of magnetite particles. The assembly of magnetosome chains is under genetic control and involves the action of an acidic protein that links magnetosomes to a novel cytoskeletal structure, presumably formed by a specific actin-like protein. A total of 28 conserved genes present in various magnetic bacteria were identified to be specifically associated with the magnetotactic phenotype, most of which are located in the genomic magnetosome island. The unique properties of magnetosomes attracted broad interdisciplinary interest, and MTB have recently emerged as a model to study prokaryotic organelle formation and evolution.
Topics: Bacteria; Bacterial Proteins; Genome, Bacterial; Iron; Magnetics; Magnetospirillum; Membrane Proteins; Organelles
PubMed: 18537832
DOI: 10.1111/j.1574-6976.2008.00116.x