Effects of pulsed magnetic field on the formation of magnetosomes in the Magnetospirillum sp. strain AMB-1.
Magnetotactic bacteria are a diverse group of microorganisms which possess one or more chains of magnetosomes and are endowed with the ability to use geomagnetic fields for direction sensing, thus providing a simple and excellent model for the study of magnetite-based magnetoreception. In this study, a 50 Hz, 2 mT pulsed magnetic field (PMF) was applied to study the effects on the formation of magnetosomes in Magnetospirillum sp. strain AMB-1. The results showed that the cellular magnetism (R(mag)) of AMB-1 culture significantly increased while the growth of cells remained unaffected after exposure. The number of magnetic particles per cell was enhanced by about 15% and slightly increased ratios of magnetic particles of superparamagnetic property (size <20 nm) and mature magnetosomes (size >50 nm) were observed after exposure to PMF. In addition, the intracellular iron accumulation slightly increased after PMF exposure. Therefore, it was concluded that 50 Hz, 2 mT PMF enhances the formation of magnetosomes in Magnetospirillum sp. strain AMB-1. Our results suggested that lower strength of PMF has no significant effects on the bacterial cell morphologies but could affect crystallization process of magnetosomes to some extent.
Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, China.
Weidong
W
Pan
Chuanfang
C
Chen
Xiaoke
X
Wang
Qiufeng
Q
Ma
Wei
W
Jiang
Jing
J
Lv
Long-Fei
LF
Wu
Tao
T
Song
D000704:Analysis of Variance; D004574:Electromagnetic Fields; D042541:Intracellular Space / Q000378:metabolism / Q000528:radiation effects; D007501:Iron / Q000378:metabolism; D055944:Magnetosomes / Q000502:physiology / Q000528:radiation effects*; D042201:Magnetospirillum / Q000502:physiology / Q000528:radiation effects* / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D010507:Periodicity
D007501:Iron