中文摘要：

趋磁细菌是一类能够沿着磁场方向运动的细菌，其共同特征是能在细胞内形成有生物膜包裹的纳米级单畴磁性晶体颗粒——磁小体。磁小体的主要化学成分是磁铁矿Fe3O4，与人工合成的磁性纳米晶体相比具有化学纯度高、粒度细而均一以及生物相容性好等优点，作为新一代纳米磁性材料，在生物化学、磁性材料、临床医药和废水处理等许多领域具有巨大的潜在应用价值。磁小体在细胞内的形成过程受到严格的生物化学机制的控制，包括铁离子的吸收、磁小体膜的形成、铁离子的转运及膜内受控的Fe2O4的生物矿化四个步骤。本文从趋磁细菌细胞内磁小体的化学组成和结构，细胞内磁小体的合成条件和生化反应机制，磁小体的磁学性质、分离纯化方法以及纳米磁小体的应用等方面综述了相关的研究进展，提出了磁小体合成机理及实践应用中尚待解决的问题，展望了未来研究磁小体及其应用的发展方向。

英文摘要：

Magnetotactic bacteria can orient and migrate along geomagnetic field lines because of their intracellular single-domain magnetic nano-crystal particles with biomembrane bounded, which are referred as magnetosomes. Magnetite Fe3O4 is the main chemical component of magnetosomes characterized by the high chemical purity, fine grain size uniformity, and good biocompatibility, which can be used as a new kind of nano- magnetic materials applied in many fields of biochemistry, magnetic materials, clinical medicine and wastewater treatment, and so on. Magnetosome formation is the mineralization process under strict biochemical mechanisms control, including four steps： iron accumulation, membrane formation, transportation and controlled biomineralization of F%04. In this paper, the characteristics of magnetotactic bacteria, chemical composition, structure, synthesis conditions and mechanisms, magnetism, separation and purification, the applications of the nano-magnetic particles are summarized and reviewed. The main problems to be resolved and the prospects of magnetosomes are also presented.