Formation of magnetite in Magnetospirillum gryphiswaldense studied with FORC diagrams
Formation of magnetite in Magnetospirillum gryphiswaldense studied with FORC diagrams
复制标题
DOI：
10.1186/bf03352894
复制
发表时间：
2009-01-01
影响因子：
3
通讯作者：
Menguy, Nicolas
中科院分区：
文献类型：
--
作者：
Carvallo, Claire;Hickey, Stanislawa;Menguy, Nicolas
为了研究在趋磁细菌中磁铁矿的形成，在一组培养的MagnetoEphillum griphiswaldense上测量FORC图，在该测定中，铁摄取仅用于磁铁矿形成而不用于细胞生长。这使得LIS能够独立于生长来跟踪磁铁矿的形成。的FORC图显示了一个清晰的演变，从我的尺寸分布与大多数的超顺磁性颗粒，以稳定的，单畴颗粒为主的分布，但仍然包含一些超顺磁性颗粒。TEM观察证实了这一演变。根据饱和等温剩磁冷却和升温曲线，Verwey转变仅在最成熟的样品中出现，且温度略低于120 K。这表明样品可能遭受了部分氧化。
In order to study the formation of magnetite in magnetotactic bacteria, FORC diagrams were measured on a set of cultured Magnetospirillum griphiswaldense, following an assay in which the iron uptake is used only for magnetite formation and not for cell growth. This enabled LIS to follow the magnetite formation independently of growth. The FORC diagrams showed a clear evolution from I size-distribution with a majority of superparamagnetic grains, to a distribution dominated by stable, single-domain grains, but still containing some superparamagnetic particles. TEM observations confirm this evolution. According to the saturation isothermal remanent magnetization cooling and warming Curves, the Verwey transition can only be seen in the most mature samples, and slightly below 120 K. This suggests that the samples may have suffered from some partial oxidation.