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Applied Microbiology and Biotechnology May 2019The scientific community's interest in magnetotactic bacteria has increased substantially in recent decades. These prokaryotes have the particularity of synthesizing... (Review)
Review
The scientific community's interest in magnetotactic bacteria has increased substantially in recent decades. These prokaryotes have the particularity of synthesizing nanomagnets, called magnetosomes. The majority of research is based on several scientific questions. Where do magnetotactic bacteria live, what are their characteristics, and why are they magnetic? What are the molecular phenomena of magnetosome biomineralization and what are the physical characteristics of magnetosomes? In addition to scientific curiosity to better understand these stunning organisms, there are biotechnological opportunities to consider. Magnetotactic bacteria, as well as magnetosomes, are used in medical applications, for example cancer treatment, or in environmental ones, for example bioremediation. In this mini-review, we investigated all the aspects mentioned above and summarized the currently available knowledge.
Topics: Bacteria; Environmental Microbiology; Iron; Magnetosomes; Nanoparticles
PubMed: 30903215
DOI: 10.1007/s00253-019-09728-9 -
Colloids and Surfaces. B, Biointerfaces Aug 2022Magnetosomes intracellularly biomineralized by Magnetotactic bacteria (MTB) are membrane-enveloped nanoparticles of the magnetic minerals magnetite (FeO) or greigite... (Review)
Review
Magnetosomes intracellularly biomineralized by Magnetotactic bacteria (MTB) are membrane-enveloped nanoparticles of the magnetic minerals magnetite (FeO) or greigite (FeS). MTB thrive in oxic-anoxic interface and exhibit magnetotaxis due to the presence of magnetosomes. Because of the unique characteristic and bionavigation inspiration of magnetosomes, MTB has been a subject of study focused on by biologists, medical pharmacologists, geologists, and physicists since the discovery. We herein first briefly review the features of MTB and magnetosomes. The recent insights into the process and mechanism for magnetosome biomineralization including iron uptake, magnetosome membrane invagination, iron mineralization and magnetosome chain assembly are summarized in detail. Additionally, the current research progress in biotechnological applications of magnetosomes is also elucidated, such as drug delivery, MRI image contrast, magnetic hyperthermia, wastewater treatment, and cell separation. This review would expand our understanding of biomineralization and biotechnological applications of bacterial magnetosomes.
Topics: Bacteria; Bacterial Proteins; Biomineralization; Ferrosoferric Oxide; Gram-Negative Bacteria; Iron; Magnetosomes
PubMed: 35605573
DOI: 10.1016/j.colsurfb.2022.112556 -
Bioactive Materials Oct 2023Magnetosomes, synthesized by magnetotactic bacteria (MTB), have been used in nano- and biotechnological applications, owing to their unique properties such as... (Review)
Review
Magnetosomes, synthesized by magnetotactic bacteria (MTB), have been used in nano- and biotechnological applications, owing to their unique properties such as superparamagnetism, uniform size distribution, excellent bioavailability, and easily modifiable functional groups. In this review, we first discuss the mechanisms of magnetosome formation and describe various modification methods. Subsequently, we focus on presenting the biomedical advancements of bacterial magnetosomes in biomedical imaging, drug delivery, anticancer therapy, biosensor. Finally, we discuss future applications and challenges. This review summarizes the application of magnetosomes in the biomedical field, highlighting the latest advancements and exploring the future development of magnetosomes.
PubMed: 37223277
DOI: 10.1016/j.bioactmat.2023.04.025 -
Journal of Molecular Microbiology and... 2013Biology textbooks taught us that eukaryotes could be easily distinguished from the far less complex bacteria. One criterion is that eukaryotes can segregate their DNA... (Review)
Review
Biology textbooks taught us that eukaryotes could be easily distinguished from the far less complex bacteria. One criterion is that eukaryotes can segregate their DNA into a lipid-bounded compartment called a nucleus which isolates DNA replication and transcription from the rest of the cytoplasmic content. The second criterion is that eukaryotes can compartmentalize their cytoplasm so as to isolate specific pathways, enzymes and chemical reactions in membrane-bounded subcellular compartments called organelles. Time and high resolution imaging taught us that the story is a little more complicated. In fact, bacteria too can isolate cell components in subcellular compartments, including, in rare cases, their DNA. Clearly, some bacteria also have the capacity to isolate reactions that require a specific chemistry or that generate toxic byproducts within specialized organelles. Despite the significant advances made in the field of bacterial cell biology in the past 15 years, little is known about the mechanisms employed by bacteria to shape, position and segregate organelles, or how the cells can discriminate and address specific proteins to these compartments. Then, if eukaryotes did not invent organelles or the nucleus, who did? Are bacteria with a complex cell plan providing us with an unexpected opportunity to investigate how organelles came to exist? Is it possible that the mechanisms leading to cell compartmentalization in eukaryotes were invented by bacteria? Or, by studying how bacterial organelles are formed, will we discover new ways to control membrane curvature, target proteins, organize and segregate organelles?
Topics: Bacterial Proteins; Cytoplasm; Genes, Bacterial; Intracellular Membranes; Magnetosomes; Magnetospirillum; Proteomics
PubMed: 23615197
DOI: 10.1159/000346655 -
Microbial Cell Factories Oct 2020Magnetotactic bacteria have the unique ability to synthesize magnetosomes (nano-sized magnetite or greigite crystals arranged in chain-like structures) in a variety of... (Review)
Review
Magnetotactic bacteria have the unique ability to synthesize magnetosomes (nano-sized magnetite or greigite crystals arranged in chain-like structures) in a variety of shapes and sizes. The chain alignment of magnetosomes enables magnetotactic bacteria to sense and orient themselves along geomagnetic fields. There is steadily increasing demand for magnetosomes in the areas of biotechnology, biomedicine, and environmental protection. Practical difficulties in cultivating magnetotactic bacteria and achieving consistent, high-yield magnetosome production under artificial environmental conditions have presented an obstacle to successful development of magnetosome applications in commercial areas. Here, we review information on magnetosome biosynthesis and strategies for enhancement of bacterial cell growth and magnetosome formation, and implications for improvement of magnetosome yield on a laboratory scale and mass-production (commercial or industrial) scale.
Topics: Bacteria; Bacterial Proteins; Ferrosoferric Oxide; Industrial Microbiology; Magnetosomes
PubMed: 33081818
DOI: 10.1186/s12934-020-01455-5 -
Sheng Wu Gong Cheng Xue Bao = Chinese... Sep 2021The targeting of anti-tumor drugs is an important means of tumor treatment and reducing drug side effects. Oxygen-depleted hypoxic regions in the tumour, which oxygen... (Review)
Review
The targeting of anti-tumor drugs is an important means of tumor treatment and reducing drug side effects. Oxygen-depleted hypoxic regions in the tumour, which oxygen consumption by rapidly proliferative tumour cells, are generally resistant to therapies. Magnetotactic bacteria (MTB) are disparate array of microorganism united by the ability to biomineralize membrane-encased, single-magnetic-domain magnetic crystals (magnetosomes) of minerals magnetite or greigite. MTB by means of flagella, migrate along geomagnetic field lines and towards low oxygen concentrations. MTB have advantage of non-cytotoxicity and excellent biocompatibility, moreover magnetosomes (BMs) is more powerful than artificial magnetic nanoparticles(MNPs). This review has generally described the biological and physical properties of MTB and magnetosomes, More work deals with MTB which can be used to transport drug into tumor based on aerotactic sensing system as well as the competition of iron which is a key factor to proliferation of tumor. In addition, we summarized the research of magnetosomes, which be used as natural nanocarriers for chemotherapeutics, antibodies, vaccine DNA. Finally, We analyzed the problems faced in the tumor treatment using of MTB and bacterial magnetosomes and prospect development trends of this kind of therapy.
Topics: Bacteria; Ferrosoferric Oxide; Gram-Negative Bacteria; Magnetics; Magnetosomes; Neoplasms
PubMed: 34622627
DOI: 10.13345/j.cjb.210263 -
Journal of Basic Microbiology Aug 2017Magnetotactic bacteria (MTB) have started to be employed for the biosynthesis of magnetic nanoparticles, due to the rapidly increasing demand for nanoparticles in... (Review)
Review
Magnetotactic bacteria (MTB) have started to be employed for the biosynthesis of magnetic nanoparticles, due to the rapidly increasing demand for nanoparticles in biomedical, biotechnology and environmental protection. MBT are the group of prokaryotes that have the ability to produce bio-magnetic minerals or bio-magnetic crystals of either magnetite (Fe O ) or greigite (Fe S ) in numerous shapes and size ranges, known as magnetosomes (MS). MS compel MTB to respond to the applied external magnetic field. However, it is extremely difficult to grow MTB and produce high yield of MS under artificial environmental conditions, thus creating a major hurdle to relocate MTB technology from laboratory scale to industrial or commercial level. Therefore, to best of our knowledge this review is the first attempt to highlight existing research developments about the laboratory scale and mass production of MS by MTB. Moreover, the optimum culture media and environmental conditions used for the cultivation of MTB were also considered. Finally, future research is encouraged for the improvement of MS yield which will result in the development of advanced nanotechnology/magnetotechnology.
Topics: Bacteria; Bacteriological Techniques; Culture Media; Ferrosoferric Oxide; Iron; Magnetics; Magnetosomes; Nanoparticles; Nanotechnology; Phylogeny; Sulfides
PubMed: 28464298
DOI: 10.1002/jobm.201700052 -
Molecules (Basel, Switzerland) Sep 2018Magnetotactic bacteria (MTB) biomineralize magnetosomes, which are defined as intracellular nanocrystals of the magnetic minerals magnetite (Fe₃O₄) or greigite... (Review)
Review
Magnetotactic bacteria (MTB) biomineralize magnetosomes, which are defined as intracellular nanocrystals of the magnetic minerals magnetite (Fe₃O₄) or greigite (Fe₃S₄) enveloped by a phospholipid bilayer membrane. The synthesis of magnetosomes is controlled by a specific set of genes that encode proteins, some of which are exclusively found in the magnetosome membrane in the cell. Over the past several decades, interest in nanoscale technology (nanotechnology) and biotechnology has increased significantly due to the development and establishment of new commercial, medical and scientific processes and applications that utilize nanomaterials, some of which are biologically derived. One excellent example of a biological nanomaterial that is showing great promise for use in a large number of commercial and medical applications are bacterial magnetite magnetosomes. Unlike chemically-synthesized magnetite nanoparticles, magnetosome magnetite crystals are stable single-magnetic domains and are thus permanently magnetic at ambient temperature, are of high chemical purity, and display a narrow size range and consistent crystal morphology. These physical/chemical features are important in their use in biotechnological and other applications. Applications utilizing magnetite-producing MTB, magnetite magnetosomes and/or magnetosome magnetite crystals include and/or involve bioremediation, cell separation, DNA/antigen recovery or detection, drug delivery, enzyme immobilization, magnetic hyperthermia and contrast enhancement of magnetic resonance imaging. Metric analysis using Scopus and Web of Science databases from 2003 to 2018 showed that applied research involving magnetite from MTB in some form has been focused mainly in biomedical applications, particularly in magnetic hyperthermia and drug delivery.
Topics: Bacteria; Bacterial Proteins; Biotechnology; Ferrosoferric Oxide; Iron; Magnetosomes; Nanoparticles; Sulfides
PubMed: 30249983
DOI: 10.3390/molecules23102438 -
Scientific Reports Jul 2020Magnetotactic bacteria are aquatic microorganisms with the ability to biomineralise membrane-enclosed magnetic nanoparticles, called magnetosomes. These magnetosomes are...
Magnetotactic bacteria are aquatic microorganisms with the ability to biomineralise membrane-enclosed magnetic nanoparticles, called magnetosomes. These magnetosomes are arranged into a chain that behaves as a magnetic compass, allowing the bacteria to align in and navigate along the Earth's magnetic field lines. According to the magneto-aerotactic hypothesis, the purpose of producing magnetosomes is to provide the bacteria with a more efficient movement within the stratified water column, in search of the optimal positions that satisfy their nutritional requirements. However, magnetosomes could have other physiological roles, as proposed in this work. Here we analyse the role of magnetosomes in the tolerance of Magnetospirillum gryphiswaldense MSR-1 to transition metals (Co, Mn, Ni, Zn, Cu). By exposing bacterial populations with and without magnetosomes to increasing concentrations of metals in the growth medium, we observe that the tolerance is significantly higher when bacteria have magnetosomes. The resistance mechanisms triggered in magnetosome-bearing bacteria under metal stress have been investigated by means of x-ray absorption near edge spectroscopy (XANES). XANES experiments were performed both on magnetosomes isolated from the bacteria and on the whole bacteria, aimed to assess whether bacteria use magnetosomes as metal storages, or whether they incorporate the excess metal in other cell compartments. Our findings reveal that the tolerance mechanisms are metal-specific: Mn, Zn and Cu are incorporated in both the magnetosomes and other cell compartments; Co is only incorporated in the magnetosomes, and Ni is incorporated in other cell compartments. In the case of Co, Zn and Mn, the metal is integrated in the magnetosome magnetite mineral core.
Topics: Bacterial Proteins; Copper; Ferrosoferric Oxide; Magnetosomes; Magnetospirillum; Manganese; Metals; Nanoparticles; Nickel; Oxidative Stress; Synchrotrons; Zinc
PubMed: 32651449
DOI: 10.1038/s41598-020-68183-z -
Nanomedicine (London, England) May 2021We investigated the application of fluorescein (FL)-entrapped magnetosomes, in other words, silica-coated iron oxide nanoparticles entrapped within niosomes (SIO/NIO),...
We investigated the application of fluorescein (FL)-entrapped magnetosomes, in other words, silica-coated iron oxide nanoparticles entrapped within niosomes (SIO/NIO), in magnetically assisted photodynamic therapy (PDT) . Panc-1 cells were treated with the magnetosomes, with and without external magnetic guidance, and irradiated with blue light. Upon photoactivation, the FL-entrapped magnetosomes can produce higher singlet oxygen in comparison to FL-entrapped micelles, probably due to the higher release tendency of the photosensitizer from the former. studies in Panc-1 cells revealed magnetically assisted enhancement in the cellular uptake of the magnetosomes. Magnetic assistance also led to enhancement in PDT efficiency in cells treated with the FL-entrapped magnetosomes and light, thus highlighting their potential in PDT.
Topics: Cell Line, Tumor; Fluorescein; Magnetosomes; Nanoparticles; Photochemotherapy; Photosensitizing Agents
PubMed: 33913340
DOI: 10.2217/nnm-2020-0445