Department of Biophysics, Faculty of Medicine & Gazi Non-ionizing Radiation Protection (GNRP) Center, Gazi University, Ankara, Turkey.
Appl Biochem Biotechnol. 2013 Apr;169(8):2341-9. doi: 10.1007/s12010-013-0146-x. Epub 2013 Feb 28.
This study investigated the effects of extremely low frequency (ELF) magnetic field with/without iron(III) chloride (FeCl3) on bacterial growth and morphology. The ELF exposures were carried out using a pair of Helmholtz coil-based ELF exposure system which was designed to generate 50 Hz sinusoidal magnetic field. The field was approximately uniform throughout the axis of the coil pair. The samples which were treated or non-treated with different concentrations FeCl3 were exposed to 50 Hz, 2 millitesla (mT) magnetic field for 24 h. ELF effect on viability was assessed in terms of viable colony counts (in colony-forming unit per milliliter) with the standard plate count technique. Scanning electron microscopy was used to investigate the magnetic field effect on surface morphology of Escherichia coli. No significant results were seen in terms of cell viability between ELF and sham-exposed bacterial strains. Similarly, FeCl3 treatment did not change cell viability of E. coli samples. However, we observed some morphological changes on E. coli cell surfaces. Pore formations and membrane destruction were seen on the surface of 24 h ELF field-exposed cells. We concluded that ELF magnetic field exposure at 2 mT does not affect cell viability; however, it may affect bacterial surface morphology.
本研究调查了极低频（ELF）磁场联合/不联合三氯化铁（FeCl3）对细菌生长和形态的影响。ELF 暴露使用一对基于亥姆霍兹线圈的 ELF 暴露系统进行，该系统设计用于产生 50 Hz 正弦磁场。磁场在线圈对的轴线上大致均匀。用不同浓度的 FeCl3 处理或未处理的样品暴露于 50 Hz、2 毫特斯拉（mT）磁场 24 小时。采用标准平板计数技术，以每毫升形成菌落的单位（菌落形成单位）来评估 ELF 对存活能力的影响。扫描电子显微镜用于研究磁场对大肠杆菌表面形态的影响。ELF 和假暴露细菌菌株之间的细胞活力没有显著差异。同样，FeCl3 处理也没有改变大肠杆菌样品的细胞活力。然而，我们观察到大肠杆菌细胞表面的一些形态变化。在 24 小时 ELF 场暴露的细胞表面上观察到孔形成和膜破坏。我们得出结论，2 mT 的 ELF 磁场暴露不会影响细胞活力，但可能会影响细菌表面形态。
