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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, laser Raman spectroscopic measurements were performed with the magnetotactic bacterium, Magnetospirillum magnetotactacticum MS-1 and the fractions separated from it.
Abstract: Magnetotactic bacteria have one or more chains of magnetosome, consisting of nano-sized magnetic crystal covered with a phospholipid bilayer and use it to sense the geomagnetic fields. In order to elucidate the molecular process to make magnetosome from the iron compounds found in the bacteria, laser Raman spectroscopic measurements were performed with the magnetotactic bacterium, Magnetospirillum magnetotacticum MS-1 and the fractions separated from it. The clear Raman signals were observed at 662 cm-1 and 740 cm-1. The former was observed in whole cell and magnetosome fraction, but not in membrane and cytoplasmic fraction and assigned to the Raman signal of magnetite. The Raman signal of the latter was observed not only in the magnetosome fraction, but also in the cytoplasmic fraction and membrane fraction. This signal was assumed to ferrihydrite. Based on the results, the pathway of the magnetosome synthesis and possible roles of ferrihydrite in the magnetotactic bacteria were discussed.

8 citations

Journal ArticleDOI
TL;DR: In this paper, two soils with contrasting magnetic properties were identified in a beech forest on Monte Zuccarello (central Italy) and were analyzed for their physicochemical characteristics, the amount of magnetic minerals, and the composition of total and culturable bacterial communities, focusing on siderophore-producing bacteria (SPB).

7 citations

Journal ArticleDOI
TL;DR: For the first time, this paper introduced a cultured magnetotactic Alphaproteobacterium, able to synthesize magnetosomes in the temperatures above 30°C and reduce selenate oxyanion.
Abstract: Materials and Methods: Thirty samples were collected from various aquatic habitats. Most important physicochemical environmental factors that are involved in growth of MTB in the microcosms were investigated using inductively coupled plasma atomic emission spectroscopy (ICP-AES), portable dissolved oxygen meter, etc. Capillary racetrack technique and magnetic separation were used to purify and enrich MTB. Various isolation media were simultaneously used for isolation of a new magnetotactic bacterium in pure culture. Two imaging techniques were used to visualize the characterizations and cell division: transmission electron microscopy (TEM) and field- emission scanning electron microscopy (FESEM). Polymerase chain reaction (PCR), ChromasPro software and MEGA5 were applied for sequence analysis of the 16S rRNA gene. Results: The results revealed a correlation of important physicochemical factors such as pH and iron with growth and blooms of these bacteria in the microcosms. New strain MTB-KTN90 was isolated in a modified isolation medium at microaerophilic zone from Anzali lagoon, Iran and cultured in a modified growth medium subsequently. The phylogenetic analysis showed that the strain belongs to Alphaproteobacteria. Growth and iron uptake studies indicated an important role by this bacterium in the iron biogeochemical cycle. For the first time, this paper introduced a cultured magnetotactic Alphaproteobacterium, able to synthesize magnetosomes in the temperatures above 30°C and reduce selenate oxyanion. Conclusions: This paper may serve as a guide to screening, isolation, and cultivation of more new MTB. The new isolated strain opens up good opportunities for biotechnological applications such as medicine to bioremediation processes due to its unique abilities.

7 citations

Journal ArticleDOI
TL;DR: In vivo bioluminescence imaging revealed the viability of MSR-1, and MPI detected signals in livers and tumors, and the development of living contrast agents offers opportunities for imaging and therapy with multimodality imaging guiding development of these agents by tracking the location, viability, and resulting biological effects.
Abstract: Superparamagnetic iron oxide nanoparticles (SPIONs) can be used as imaging agents to differentiate between normal and diseased tissue or track cell movement. Magnetic particle imaging (MPI) detects the magnetic properties of SPIONs, providing quantitative and sensitive image data. MPI performance depends on the size, structure, and composition of nanoparticles. Magnetotactic bacteria produce magnetosomes with properties similar to those of synthetic nanoparticles, and these can be modified by mutating biosynthetic genes. The use of Magnetospirillum gryphiswaldense, MSR-1 with a mamJ deletion, containing clustered magnetosomes instead of typical linear chains, resulted in improved MPI signal and resolution. Bioluminescent MSR-1 with the mamJ deletion were administered into tumor-bearing and healthy mice. In vivo bioluminescence imaging revealed the viability of MSR-1, and MPI detected signals in livers and tumors. The development of living contrast agents offers opportunities for imaging and therapy with multimodality imaging guiding development of these agents by tracking the location, viability, and resulting biological effects.

7 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202339
202288
202137
202061
201950
201873