Corrigendum: Effect of oxic and anoxic conditions on intracellular storage of polyhydroxyalkanoate and polyphosphate in strain AMB-1.

[This corrects the article DOI: 10.3389/fmicb.2023.

Effect of oxic and anoxic conditions on intracellular storage of polyhydroxyalkanoate and polyphosphate in strain AMB-1.

Magnetotactic bacteria (MTB) are microorganisms widely inhabiting the oxic-anoxic interface of aquatic environments. Beside biomineralizing magnetic nanocrystals, MTBs are able to sequester various chemical elements (e.g.

Continuous Production of Biogenic Magnetite Nanoparticles by the Marine Bacterium Strain MV-1 with a Nitrous Oxide Injection Strategy.

Magnetotactic bacteria (MTB) produce magnetosomes, which are membrane-embedded magnetic nanoparticles. Despite their technological applicability, the production of magnetite magnetosomes depends on the cultivation of MTB, which results in low yields. Thus, strategies for the large-scale cultivation of MTB need to be improved.

Biogeochemical fingerprinting of magnetotactic bacterial magnetite.

Biominerals are important archives of the presence of life and environmental processes in the geological record. However, ascribing a clear biogenic nature to minerals with nanometer-sized dimensions has proven challenging. Identifying hallmark features of biologically controlled mineralization is particularly important for the case of magnetite crystals, resembling those produced by magnetotactic bacteria (MTB), which have been used as evidence of early prokaryotic life on Earth and in meteorites.

A rapid and simple preparation of amphotericin B-loaded bacterial magnetite nanoparticles.

Magnetotactic bacteria, which synthesize biological magnetite nanoparticles (BMs), are the main microbial source of magnetic nanomaterials. Although the use of BMs has been explored and for new anticancer formulations, targeted treatments of fungal and parasitic diseases would also benefit from biogenic magnetic nanoformulations. Due to the necessity of new formulations of amphotericin B, we developed a magnetic-nanoparticle based conjugate of this drug using bacterial magnetosomes.

Expanding magnetic organelle biogenesis in the domain Bacteria.

Background: The discovery of membrane-enclosed, metabolically functional organelles in Bacteria has transformed our understanding of the subcellular complexity of prokaryotic cells. Biomineralization of magnetic nanoparticles within magnetosomes by magnetotactic bacteria (MTB) is a fascinating example of prokaryotic organelles. Magnetosomes, as nano-sized magnetic sensors in MTB, facilitate cell navigation along the local geomagnetic field, a behaviour referred to as magnetotaxis or microbial magnetoreception.

In Vivo Biosynthesis of Inorganic Nanomaterials Using Eukaryotes-A Review.

Bionanotechnology, the use of biological resources to produce novel, valuable nanomaterials, has witnessed tremendous developments over the past two decades. This eco-friendly and sustainable approach enables the synthesis of numerous, diverse types of useful nanomaterials for many medical, commercial, and scientific applications. Countless reviews describing the biosynthesis of nanomaterials have been published.

Insight on thermal stability of magnetite magnetosomes: implications for the fossil record and biotechnology.

Magnetosomes are intracellular magnetic nanocrystals composed of magnetite (FeO) or greigite (FeS), enveloped by a lipid bilayer membrane, produced by magnetotactic bacteria. Because of the stability of these structures in certain environments after cell death and lysis, magnetosome magnetite crystals contribute to the magnetization of sediments as well as providing a fossil record of ancient microbial ecosystems. The persistence or changes of the chemical and magnetic features of magnetosomes under certain conditions in different environments are important factors in biotechnology and paleomagnetism.

On the origin of microbial magnetoreception.

A broad range of organisms, from prokaryotes to higher animals, have the ability to sense and utilize Earth's geomagnetic field-a behavior known as magnetoreception. Although our knowledge of the physiological mechanisms of magnetoreception has increased substantially over recent decades, the origin of this behavior remains a fundamental question in evolutionary biology. Despite this, there is growing evidence that magnetic iron mineral biosynthesis by prokaryotes may represent the earliest form of biogenic magnetic sensors on Earth.

Complete Genome Sequence of Strain BW-2, a Magnetotactic Gammaproteobacterium in the Family , Isolated from a Brackish Spring in Death Valley, California.

We report the complete 4.1-Mb genome sequence of strain BW-2, a magnetotactic, sulfur-oxidizing rod, belonging to the family of the class , that biomineralizes membrane-bounded magnetite nanocrystals in its magnetosomes. This genome sequence, in comparison with those of other magnetotactic bacteria, is essential for understanding the origin and evolution of magnetotaxis and magnetosome biomineralization.

Magnetosome Gene Duplication as an Important Driver in the Evolution of Magnetotaxis in the .

The evolution of microbial magnetoreception (or magnetotaxis) is of great interest in the fields of microbiology, evolutionary biology, biophysics, geomicrobiology, and geochemistry. Current genomic data from magnetotactic bacteria (MTB), the only prokaryotes known to be capable of sensing the Earth's geomagnetic field, suggests an ancient origin of magnetotaxis in the domain Vertical inheritance, followed by multiple independent magnetosome gene cluster loss, is considered to be one of the major forces that drove the evolution of magnetotaxis at or above the class or phylum level, although the evolutionary trajectories at lower taxonomic ranks (e.g.

Magnetosome magnetite biomineralization in a flagellated protist: evidence for an early evolutionary origin for magnetoreception in eukaryotes.

The most well-recognized magnetoreception behaviour is that of the magnetotactic bacteria (MTB), which synthesize membrane-bounded magnetic nanocrystals called magnetosomes via a biologically controlled process. The magnetic minerals identified in prokaryotic magnetosomes are magnetite (Fe O ) and greigite (Fe S ). Magnetosome crystals, regardless of composition, have consistent, species-specific morphologies and single-domain size range.

Misalignment between the magnetic dipole moment and the cell axis in the magnetotactic bacterium Magnetospirillum magneticum AMB-1.

While most quantitative studies of the motion of magnetotactic bacteria rely on the premise that the cells' magnetic dipole moment is aligned with their direction of motility, this assumption has so far rarely been challenged. Here we use phase contrast microscopy to detect the rotational diffusion of non-motile cells of Magnetospirillum magneticum AMB-1 around their magnetic moment, showing that in this species the magnetic dipole moment is, in fact, not exactly aligned with the cell body axis. From the cell rotational trajectories, we are able to infer the misalignment between cell magnetic moment and body axis with a precision of better than 1°, showing that it is, on average, 6°, and can be as high as 20°.

Uptake and persistence of bacterial magnetite magnetosomes in a mammalian cell line: Implications for medical and biotechnological applications.

Magnetotactic bacteria biomineralize intracellular magnetic nanocrystals surrounded by a lipid bilayer called magnetosomes. Due to their unique characteristics, magnetite magnetosomes are promising tools in Biomedicine. However, the uptake, persistence, and accumulation of magnetosomes within mammalian cells have not been well studied.

Growing Magnetotactic Bacteria of the Genus Magnetospirillum: Strains MSR-1, AMB-1 and MS-1.

Magnetotactic bacteria are Gram-negative, motile, mainly aquatic prokaryotes ubiquitous in freshwater and marine habitats. They are characterized by their ability to biomineralize magnetosomes, which are magnetic nanometer-sized crystals of magnetite (Fe3O4) or greigite (Fe3S4) surrounded by a lipid bilayer membrane, within their cytoplasm. For most known magnetotactic bacteria, magnetosomes are assembled in chains inside the cytoplasm, thereby conferring a permanent magnetic dipole moment to the cells and causing them to align passively with external magnetic fields.

Variation in airborne fungal spore concentrations among five monitoring locations in a desert urban environment.

Fungal spores are biological particles that are ubiquitous in the outdoor air. Spores of several very common fungal species are known allergens, with the potential to cause respiratory illnesses by exacerbating asthma and allergic rhinitis. The National Allergy Bureau typically has one monitoring station established per city to determine fungal spore counts for an entire metropolitan area.

Applications of Magnetotactic Bacteria, Magnetosomes and Magnetosome Crystals in Biotechnology and Nanotechnology: Mini-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.

Variation in airborne pollen concentrations among five monitoring locations in a desert urban environment.

The urbanization of the Las Vegas Valley has transformed this part of the Mohave Desert into a green oasis by introducing many non-native plant species, some of which are allergenic. Typically, one monitoring station is established per city to obtain pollen counts for an entire metropolitan area. However, variations in pollen concentrations could occur among different microenvironments.

Association of magnetotactic multicellular prokaryotes with Pseudoalteromonas species in a natural lagoon environment.

Magnetotactic bacteria, for the most part, are free-living, motile, unicellular prokaryotes that inhabit almost all marine and freshwater environments. One notable exception to the unicellular mode, however, are the magnetotactic multicellular prokaryotes. These morphologically unique prokaryotes (e.

Culture-independent characterization of a novel magnetotactic member affiliated to the Beta class of the Proteobacteria phylum from an acidic lagoon.

Magnetotactic bacteria (MTB) comprise a group of motile microorganisms common in most mesothermal aquatic habitats with pH values around neutrality. However, during the last two decades, a number of MTB from extreme environments have been characterized including: cultured alkaliphilic strains belonging to the Deltaproteobacteria class of the Proteobacteria phylum; uncultured moderately thermophilic strains belonging to the Nitrospirae phylum; cultured and uncultured moderately halophilic or strongly halotolerant bacteria affiliated with the Deltaproteobacteria and Gammaproteobacteria classes and an uncultured psychrophilic species belonging to the Alphaproteobacteria class. Here, we used culture-independent techniques to characterize MTB from an acidic freshwater lagoon in Brazil (pH ∼ 4.

Genomic expansion of magnetotactic bacteria reveals an early common origin of magnetotaxis with lineage-specific evolution.

The origin and evolution of magnetoreception, which in diverse prokaryotes and protozoa is known as magnetotaxis and enables these microorganisms to detect Earth's magnetic field for orientation and navigation, is not well understood in evolutionary biology. The only known prokaryotes capable of sensing the geomagnetic field are magnetotactic bacteria (MTB), motile microorganisms that biomineralize intracellular, membrane-bounded magnetic single-domain crystals of either magnetite (FeO) or greigite (FeS) called magnetosomes. Magnetosomes are responsible for magnetotaxis in MTB.

Localized iron accumulation precedes nucleation and growth of magnetite crystals in magnetotactic bacteria.

Many magnetotactic bacteria (MTB) biomineralize magnetite crystals that nucleate and grow inside intracellular membranous vesicles that originate from invaginations of the cytoplasmic membrane. The crystals together with their surrounding membranes are referred to magnetosomes. Magnetosome magnetite crystals nucleate and grow using iron transported inside the vesicle by specific proteins.

Desulfamplus magnetovallimortis gen. nov., sp. nov., a magnetotactic bacterium from a brackish desert spring able to biomineralize greigite and magnetite, that represents a novel lineage in the Desulfobacteraceae.

A magnetotactic bacterium, designated strain BW-1, was isolated from a brackish spring in Death Valley National Park (California, USA) and cultivated in axenic culture. The Gram-negative cells of strain BW-1 are relatively large and rod-shaped and possess a single polar flagellum (monotrichous). This strain is the first magnetotactic bacterium isolated in axenic culture capable of producing greigite and/or magnetite nanocrystals aligned in one or more chains per cell.