细菌磁小体形成机制和应用研究进展

趋磁细菌(magnetotactic bacteria,MTB)可以在细胞内形成磁小体(magnetosome,MS)并在磁场作用下定向运动。MTB的MS合成是一个多基因参与的复杂过程。MS由于其优良的性能而有着广阔的应用前景。本文对MS的合成机制和应用的研究进展进行了初步的概述。

Research Progress and Application Prospect of Magnetosome

Magnetotactic bacteria orient and migrate along geomagnetic field lines.This ability is based on intracellular magnetic structures,the magnetosomes.Magnetotactic bacteria are Gram-negative,ubiquitous and common in sediments of freshwater or marine habitats,in stratified water columns and wet soils.They represent a diverse group of microorganisms with respect to morphology,physiology and phylogeny.The narrow size distributions and uniform,species-specific crystal morphologies of bacterial magnetosomes imply a high degree of biological control over the mineralization process.The magnetosome formation is achieved by a complex process in which multiple gene products participated.There are two hypotheses on magnetosome formation mechanism that have been proposed,the hypothesis of cytoplasimic membrane invagination and the hypothesis of enwrapping after crystal development.Most of the genes encoding proteins constituting the magnetosome subproteome were assigned to ORFs in the mamAB, mamDC,and mms6 clusters in the putative magnetosome island.The exact role of these magnetosome-specific proteins has not been elucidated,but it has been suggested that they have specific functions in iron accumulation,nucleation of minerals,and redox and pH control.More and more evidence demonstrated that magnetosome of magnetotactic bacteria appear to possess many of the defining features of eukaryotic membrane-bounded organelles.The unique characteristics of bacterial magnetosomes have attracted broad interdisciplinary research interest.For its superexcellent properities magnetosome has great potential biotechnological applications.This review focuses on the current knowledge about the mechanism of magnetosome formation and its general application.