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: In this paper, the authors focus on factors that play a role in the organization of magnetosomes, which serve as actuators and area means to align the bacteria with the Earth's magnetic field lines when they swim in search of particular habitats in aqueous environments they live in.
Abstract: Several organisms possess a genetic program enabling them to form a mineral, a process termed biomineralization. The structure and composition of biominerals equip the biomineralizing organisms with functionalities that abiotic materials made of the same mineral do not necessarily possess. Even primary organisms such as bacteria are able to produce materials with properties superior to those of human-made equivalents. Magnetotactic bacteria represent a paradigm of such microorganisms. These organisms synthesize a hierarchical one-dimensional magnetic nanostructure based on the alignment of magnetosomes—organelles embedded in a vesicle dedicated to biomineralization and made of magnetic nanoparticles (magnetite (Fe3O4) or greigite (Fe3S4)). This article focuses on factors that play a role in the organization of these magnetosomes. The chains, which are based on aligned particles that have biologically controlled ultrastructure, size, morphology, organization, and orientation, serve as actuators and area means to align the bacteria with the Earth’s magnetic field lines when they swim in search of particular habitats in the aqueous environments they live in.
11 citations
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TL;DR: The fermentation regime established in this study facilitates stable oxygen control during culturing of Magnetospirillum gryphiswaldense and will facilitate the highly reproducible laboratory-scale bioproduction of magnetosomes for a diverse range of future applications in the fields of biotechnology and biomedicine.
Abstract: Magnetosomes produced by magnetotactic bacteria represent magnetic nanoparticles with unprecedented characteristics. However, their use in many biotechnological applications has so far been hampered by their challenging bioproduction at larger scales. Here, we developed an oxystat batch fermentation regime for microoxic cultivation of Magnetospirillum gryphiswaldense in a 3 L bioreactor. An automated cascade regulation enabled highly reproducible growth over a wide range of precisely controlled oxygen concentrations (1–95% of air saturation). In addition, consumption of lactate as the carbon source and nitrate as alternative electron acceptor were monitored during cultivation. While nitrate became growth limiting during anaerobic growth, lactate was the growth limiting factor during microoxic cultivation. Analysis of microoxic magnetosome biomineralization by cellular iron content, magnetic response, transmission electron microscopy and small-angle X-ray scattering revealed magnetosomal magnetite crystals were highly uniform in size and shape. The fermentation regime established in this study facilitates stable oxygen control during culturing of Magnetospirillum gryphiswaldense. Further scale-up seems feasible by combining the stable oxygen control with feeding strategies employed in previous studies. Results of this study will facilitate the highly reproducible laboratory-scale bioproduction of magnetosomes for a diverse range of future applications in the fields of biotechnology and biomedicine.
11 citations
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TL;DR: The mechanism of magnetosomes probe was interpreted for proposing the practical way with high-performance on controlling the aflatoxins contamination in liquid foods basing on immunomagentic separation technique.
11 citations
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TL;DR: Several magnetotactic bacteria (MTB) have been isolated from iron cap belt, surface soil of intermediate belt and primary iron ore belt of Tieshan iron ore in Hubei Province, China.
11 citations
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TL;DR: Magnetotactic bacteria (MTB) are a group of phylogenetically diverse and morphologically varied microorganisms with a magnetoresponsive capability called magnetotaxis or microbial magnetoreception as mentioned in this paper .
Abstract: Magnetotactic bacteria (MTB) are a group of phylogenetically diverse and morphologically varied microorganisms with a magnetoresponsive capability called magnetotaxis or microbial magnetoreception. MTB are a distinctive constituent of the microbiome of aquatic ecosystems because they use Earth's magnetic field to align themselves in a north or south facing direction and efficiently navigate to their favored microenvironments. They have been identified worldwide from diverse aquatic and waterlogged microbiomes, including freshwater, saline, brackish and marine ecosystems, and some extreme environments. MTB play important roles in the biogeochemical cycling of iron, sulphur, phosphorus, carbon and nitrogen in nature and have been recognized from in vitro cultures to sequester heavy metals like selenium, cadmium, and tellurium, which makes them prospective candidate organisms for aquatic pollution bioremediation. The role of MTB in environmental systems is not limited to their lifespan; after death, fossil magnetosomal magnetic nanoparticles (known as magnetofossils) are a promising proxy for recording paleoenvironmental change and geomagnetic field history. Here, we summarize the ecology, evolution, and environmental function of MTB and the paleoenvironmental implications of magnetofossils in light of recent discoveries.
11 citations