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.
Pan
Weidong
W
Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, China.
Chen
Chuanfang
C
Wang
Xiaoke
X
Ma
Qiufeng
Q
Jiang
Wei
W
Lv
Jing
J
Wu
Long-Fei
LF
Song
Tao
T
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