title: [The effects of electromagnetic radiation of extremely high frequency and low intensity on the growth rate of bacteria Escherichia coli and the role of medium pH].
abstract: It has been shown that coherent electromagnetic irradiation (EMI) of extremely high frequency (45-53 GHz) or millimeter waves (wavelength 5.6-6.7 mm) of low intensity (flux capacity 0.06 mW/cm2) of Escherichia coli K12, grown under anaerobic conditions during the fermentation of sugar (glucose) for 30 min or 1 h, caused a decrease in their growth rate, the maximum inhibitory effect being achieved at a frequency of 51.8 or 53 GHz. This effect depended on medium pH when the maximal action was determined at pH 7.5. In addition, separate 30-min of 1-h irradiation (frequency 51.8 or 53 GHz) of doubly distilled water or some inorganic ions contained in Tris-phosphate buffer where the cells were transferred induced oppositely directed changes in further growth of these bacteria under anaerobic conditions; irradiation of water caused a decrease in the growth rate of bacteria. A significant change in pH of water (0.5-1.5 unit) was induced by a 30-irradiation at a frequency of 49, 50.3, 51.8, or 53 GHz, when the initial pH value was 6.0 or 8.0, but not 7.5. These results indicate the changes in the properties of water and its role in the effects of EMI of extremely high frequency. The marked effect of EMI on bacteria disappeared upon repeated irradiation for 1 h at a frequency of 51.8 or 53 GHz with an interval of 2 hours. This result indicates some compensatory mechanisms in bacteria.
authors.forename: A
authors.initials: A
authors.lastname: Tadevosian
authors.forename: V
authors.initials: V
authors.lastname: Kalantarian
authors.forename: A
authors.initials: A
authors.lastname: Trchunian
mesh_terms: D000693:Anaerobiosis / Q000528:radiation effects; D003470:Culture Media; D004307:Dose-Response Relationship, Radiation; D048168:Escherichia coli K12 / Q000254:growth & development*; D005285:Fermentation / Q000528:radiation effects*; D005947:Glucose / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008872:Microwaves; D014867:Water / Q000378:metabolism
chemical_list: D003470:Culture Media; D014867:Water; D005947:Glucose