Effects of combined magnetic fields on bacteria Rhodospirillum rubrum VKM B‐1621

Abstract

Bacteria are the simplest model of living organisms and thus are a convenient object for magnetobiological research. This paper describes some effects of combined magnetic fields (CMFs) on the bacterium Rhodospirillum rubrum strain VKM B-1621, which is not a pathogen but was selected due to its wide spectrum of growth abilities. The authors chose magnetic field-resonant phosphorus and iron (Fe ) because P-containing biochemical compounds (standard abbreviations PP , AMP, ADP, ATP) provide energy flows in bacteria while iron could take part in formation of magnetosensitive intracellular inclusions. CMFs were produced by interaction of a geomagnetic field (В ) and an alternating electromagnetic field (В ), which were similar in their intensities. Their magnetic characteristics were as follows: (CMF-1) В = 46.80 µТ, В = 86.11 µT, f = 807.0 Hz; (CMF-2) В = 46.80 µТ, В = 86.11 µT, f = 38.3 Hz; that is, the frequencies of applied alternating electromagnetic fields coincided with cyclotron frequencies of phosphorus or ferric ions, respectively. The blank variants were exposed to the geomagnetic field. The CMFs increased bacterial consumption of dissolved iron as measured by residual concentrations of iron in the medium (P > 99%). An increase of bacterial nitrate reduction in the CMFs was statistically insignificant (P > 90%) when measured by residual concentrations of nitrate. Application of CMFs can influence bacterial activity and metabolism. Bioelectromagnetics. 2018;39:485-490, 2018. © 2018 Wiley Periodicals, Inc.

Influence of Calcium Resonance-Tuned Low-Frequency Magnetic Fields on Daphnia magna

“…On the other hand, Lednev’s model suggests the maximum biological effects of an alternating magnetic field with an intensity that exceeds that of the static magnetic field by approximately 1.8 times [ 11 ]. The effectiveness of this Hac/Hdc ratio has more experimental confirmations that were performed mainly using the organisms but not cell cultures as exposed objects [ 9 , 13 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ]. Probably, the above-described effects of alternating magnetic fields with different intensities of 0.9 and 1.8 Hac/Hdc regarding Blanchard-Blackman and Lednev’s models [ 11 , 12 ] might be due to the specificity of cells and organisms as objects with different levels of biological organization.…”

Molecular Biological Effects of Weak Low-Frequency Magnetic Fields: Frequency–Amplitude Efficiency Windows and Possible Mechanisms

“…Combined magnetic fields with this intensity ratio also affected calcium efflux from plasma membrane vesicles isolated from Spinacia oleracea L. [ 14 ] and inhibited growth in HeLa, VH-10, and Saos-2-His-273 cell cultures [ 15 ]. On the other hand, biological effects were found in alternating magnetic fields with a cyclotron frequency for various ions and with an amplitude exceeding the intensity of a static magnetic field by about 1.8 times [ 5 , 11 , 12 , 16 , 17 , 27 , 28 , 29 , 30 , 31 ]. To explain the biological effects of alternating magnetic fields with a frequency that formally corresponds to the cyclotron frequency for different ions and an amplitude ratio of B AC / B DC ~0.9, Blackman and Blanchard proposed a model of ion parametric resonance [ 32 ].…”

“…This frequency for calcium ions in the geomagnetic field at temperate latitudes of 40–55 µT will be about 30–42 Hz. These values have often been described as B DC and f AC in the experiments testing resonance biophysical models for calcium ions [ 5 , 6 , 16 , 29 , 30 , 90 ]. The 30–42 Hz frequency should correspond to a chemical oscillation period of approximately 24–33 ms.…”

Bioenergetics of the polyphosphates accumulation in Pseudomonas aeruginosa via polyphosphate kinase activation by choline in a lung colonization model

“…Bacterial are polymers of phosphate ( ) from 5 to 1000 s units that form intracellular magnet-sensitive inclusions that contain magnesium, calcium, cobalt, chromium, or iron (Mg +2 , Ca +2 , Co +2 , Cr +2 , or Fe +2 ) [11] , [12] , [13] and play key roles in stress response, swimming, and swarming, which are essential activities for bacterial infection and colonization [14] . accumulation occurs as a result of choline catabolism [3] that may occur through inhibition of the degradation of to by exo-polyphosphate phosphatase (PPX) or synthesis via ATP addition to by activation of polyphosphate kinase (PPK).…”