title: Effect of extremely low frequency electromagnetic fields on bacterial membrane.
abstract: OBJECTIVE
  The effect of extremely low frequency electromagnetic fields (ELF-EMF) on bacteria has attracted attention due to its potential for beneficial uses. This research aimed to determine the effect of ELF-EMF on bacterial membrane namely the membrane potential, surface potential, hydrophobicity, respiratory activity and growth.
  
  
  METHODS
  Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli were subjected to ELF-EMF, 50 Hz, 1 mT for 2 h. Membrane potential was determined by fluorescence spectroscopy with or without EDTA (Ethylenediaminetetraacetic acid) with DisC3(5) (3,3-dipropylthiacarbocyanine iodide), zeta potential measurements were performed by electrophoretic mobility, hydrophobicity of the membrane was measured with MATH (Microbial Adhesion to Hydrocarbons) test, respiratory activity was determined with CTC (5-Cyano-2,3-ditolyl tetrazolium chloride), colony forming unit (CFU) and DAPI (4',6-diamidino-2-phenylindole, dihydrochloride) was used for growth determinations.
  
  
  RESULTS
  ELF-EMF caused changes in physicochemical properties of both Gram-positive and Gram-negative bacteria. Hyperpolarization was seen in S. aureus and EDTA-treated E. coli. Surface potential showed a positive shift in S. aureus contrariwise to the negative shift seen in EDTA-untreated E. coli. Respiratory activity increased in both bacteria. A slight decrease in growth was observed.
  
  
  CONCLUSIONS
  These results show that ELF-EMF affects the crucial physicochemical processes in both Gram-positive and Gram-negative bacteria which need further research.
authors.affiliation: a Biophysics Department , School of Medicine, Faculty of Medicine, Medeniyet University , Istanbul ;
authors.forename: Sule
authors.initials: S
authors.lastname: Oncul
authors.affiliation: b Department of Biophysics , Marmara University School of Medicine , Istanbul , Turkey ;
authors.forename: Esra M
authors.initials: EM
authors.lastname: Cuce
authors.affiliation: c Department of Microbiology , Marmara University School of Medicine , Istanbul , Turkey.
authors.forename: Burak
authors.initials: B
authors.lastname: Aksu
authors.affiliation: b Department of Biophysics , Marmara University School of Medicine , Istanbul , Turkey ;
authors.forename: Ayse
authors.initials: A
authors.lastname: Inhan Garip
mesh_terms: D002462:Cell Membrane / Q000502:physiology* / Q000528:radiation effects; D002463:Cell Membrane Permeability / Q000502:physiology* / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D004574:Electromagnetic Fields; D004926:Escherichia coli / Q000502:physiology* / Q000528:radiation effects; D008560:Membrane Fluidity / Q000502:physiology / Q000528:radiation effects; D008564:Membrane Potentials / Q000502:physiology* / Q000528:radiation effects; D011829:Radiation Dosage; D013211:Staphylococcus aureus / Q000502:physiology* / Q000528:radiation effects
keywords: ELF-EMF; bacterial growth; bacterial hydrophobicity; bacterial membrane potential; respiratory activity; surface potential