bullet-shaped magnet

MTB is a kind of energy to the magnetic field lines along the bacteria swim in general, can be synthesized in the cell biofilm coated, intact and unique crystalline, nanometer-sized, single magnetic domain (SD) of magnetite ( Fe3O4) or greigite (Fe3S4) crystalline particles - magnetic bodies. Magnetosomes mineralized biological control product is to reveal the biological and cognitive biomineralization - the important role of the geomagnetic field study; fossil Magnetosomes life is to find the ancient ruins of the ancient biological markers and conduct environmental research potential alternative indicators; Magnetosomes also as a new bio-nano-magnetic materials in the field of biomedicine and materials science has broad tube magnets application prospects.

Nitrospira bacteria bacillus M. bavaricum large door in the intracellular synthesis of thousands of sub-bullet-shaped magnetite magnetosomes, its mineralization is another MTB dozens of times, and its mineralization mechanism, iron cycling and sediment remanence contributions concern. Its unique bullet-shaped magnetite particles is the most obvious sign of biogenic, life is as ancient monuments and paleoenvironmental reconstruction of the important biomarkers.

Geology Earth Earth Deep Structure and Process Research of the geomagnetic field and the Earth's internal processes subject groups doctoral Li Jinhua (now postdoctoral) and mentor Pan YX researcher, who use self-designed MTB dedicated collection system successfully from Beijing Miyun Reservoir enriched sediments sufficient amount of pure MTB bacilli MYR-1 samples, and studied its bullet-shaped magnetic bodies of biomineralization mechanism and magnetic properties. The results showed that: first, the discovery of a large Miyun coli MYR-1 with the earlier discovered in Germany Lake Chiemsee M. bavaricum highly similar rod-shaped cells, the average length and diameter were ~ 6.4 μm, and ~ 1.5 μm. Each MYR-1 intracellular bacteria can synthesize more than 500 sub-bullet-shaped magnetic bodies, are assembled into 3-5 bundles of parallel bundles magnetosome chain structure, crystal direction substantially parallel to the long axis of the chain. Magnetosome average length and width of ~ 104 nm, respectively, and ~ 38 nm (Figure a); Second, transmission electron microscopy studies show that, MYR-1 synthetic magnetic bodies of magnetite crystals with a two-stage growth pattern, i.e. equiaxed magnetic bodies grow to a certain size (~ 20 nm), the anisotropic growth of crystals of Drawer magnets  particles generally along the [100] direction (hard magnetization axis direction) rather than the conventional [111 ] direction (easy magnetization axis direction) of elongated growth, suggesting a strong role in biological control (figure b, and c); third, magnetic analysis showed that although MYR-1 of the magnetic bodies using the [100] crystal orientation, but the magnetic Iron remarkable shape anisotropy and chain bundle strong magnetostatic interaction between particles in the same direction, each beam Magnetosomes chain is equivalent to a large uniaxial anisotropy SD granule cells remained close to the total magnetic moment or the sum of all individual magnetic moments of the sum of bodies, thereby effectively improving the efficiency of magnetic response of the cell.