Topic
Magnetotactic bacteria
About: Magnetotactic bacteria is a research topic. Over the lifetime, 1118 publications have been published within this topic receiving 43741 citations.
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TL;DR: It is concluded that the biomineralization of magnetite occurs rapidly in magnetotactic bacteria on a similar time scale to high-temperature chemical precipitation reactions, and it is suggested that this finding is caused by a biological catalysis of the process.
Abstract: Magnetosomes are magnetite nanoparticles formed by biomineralization within magnetotactic bacteria. Although there have been numerous genetic and proteomic studies of the magnetosome-formation process, there have been only limited and inconclusive studies of mineral-phase evolution during the formation process, and no real-time studies of such processes have yet been performed. Thus, suggested formation mechanisms still need substantiating with data. Here we report the examination of the magnetosome material throughout the formation process in a real-time in vivo study of Magnetospirillum gryphiswaldense, strain MSR-1. Transmission EM and x-ray absorption spectroscopy studies reveal that full-sized magnetosomes are seen 15 min after formation is initiated. These immature magnetosomes contain a surface layer of the nonmagnetic iron oxide-phase hematite. Mature magnetite is found after another 15 min, concurrent with a dramatic increase in magnetization. This rapid formation result is contrary to previously reported studies and discounts the previously proposed slow, multistep formation mechanisms. Thus, we conclude that the biomineralization of magnetite occurs rapidly in magnetotactic bacteria on a similar time scale to high-temperature chemical precipitation reactions, and we suggest that this finding is caused by a biological catalysis of the process.
96 citations
TL;DR: H hippocampal material from deceased normal and epileptic subjects, and from the surgically removed epileptogenic zone of a living patient, had magnetic characteristics similar to those reported for other parts of the brain, which indicate that the magnetic material is present in a wide range of grain sizes.
95 citations
TL;DR: In this article, the correlations between magnetosome mineral habits and the phylogenetic affiliations of magnetotactic bacteria have been reviewed, and it is shown that these correlations have important implications for the evolution of magnetosomes synthesis, and thus magnetotaxis.
Abstract: Magnetotactic bacteria (MTB) biomineralize magnetosomes, nano-scale crystals of magnetite or greigite in membrane enclosures, that comprise a permanent magnetic dipole in each cell MTB control the mineral composition, habit, size, and crystallographic orientation of the magnetosomes, as well as their arrangement within the cell Studies involving magnetosomes that contain mineral and biological phases require multidisciplinary efforts Here we use crystallographic, genomic and phylogenetic perspectives to review the correlations between magnetosome mineral habits and the phylogenetic affiliations of MTB, and show that these correlations have important implications for the evolution of magnetosome synthesis, and thus magnetotaxis
95 citations
TL;DR: Ferromagnetic resonance spectroscopy (FMR) is in theory capable of detecting the distinctive magnetic anisotropy produced by chain arrangement and crystal elongation of magnetotactic bacteria.
94 citations
TL;DR: The data indicate that magnetosome linearity persists long after cells are disrupted, consistent with prior observations that in some magnetotcocci the magnetosomes chains pass through the cell interior, precluding continuous contact with the cell wall and implying additional support structures exist in some species.
93 citations