Biological effects of static magnetic fields and zinc isotopes on E. coli bacteria.

The sensitivity of intracellular enzymatic systems to static magnetic fields (SMFs) and magnetic isotopes has been shown both in vitro and in vivo. These effects are determined by the spin-dependent magnetosensitive stages of enzymatic reactions. The search for experimental evidence of the combined effect of SMFs and zinc magnetic isotope 67 Zn on the intracellular processes on Escherichia coliEscherichia coli bacteria has taken place in vivo. The joint effects of external SMFs and magnetic zinc isotope 67 Zn on vital functions of E.coli bacteria have been shown experimentally. The combined effect of isotope 67 Zn and weak SMFs (25-35 mT) causes a 2-4-fold increase in the colony-forming ability and growth rate constants of bacteria E. coli compared with nonmagnetic zinc isotopes 64,66 Zn. The effects of SMFs in the range of 2.2-8 mT were detected for all bacteria, regardless of zinc isotope content in the media. An increase in ATP concentration in E. coli was detected for bacteria grown on a medium with the magnetic isotope 67 Zn in the SMF range of 2.2-4.2 mT. The major elements' (Na, K, Ca, Mg, P, Zn) metabolism in E. coli depend on the intensity of SMFs and zinc isotopes. These data confirm the existence of intracellular enzymatic processes stages that are sensitive to SMFs and magnetic moments of atomic nuclei. It is important to note that magnetic zinc 67 Zn and magnesium 25 Mg isotopes induce effects on viability of E. coli in different SMF ranges. Bioelectromagnetics. 40:62-73, 2019. © 2018 Wiley Periodicals, Inc.

Magnetosensitivity of bacteria E. coli: Magnetic isotope and magnetic field effects.

The biological effects of a 25 Mg nuclear spin and weak magnetic fields have been found and studied by using bacterial cells of Escherichia coli (E. coli) grown on standard M9 nutrient media with different isotopes of magnesium: 24 Mg, 25 Mg, 26 Mg, and a natural mixture of Mg isotopes. Among these isotopes only 25 Mg has a nuclear spin I = 5/2 and nuclear magnetic moment which have been known to affect enzymatic processes in vitro due to hyperfine interactions with uncoupled electrons of substrates. Other non-magnetic magnesium isotopes, 24 Mg and 26 Mg, have neither a nuclear spin (I = 0) nor a nuclear magnetic moment. Bacterial cells grown on 25 Mg-media and enriched with this isotope manifest a higher growth rate and colony-forming units (CFU) compared with cells grown on media containing nonmagnetic 24 Mg and 26 Mg isotopes. Magnetic field dependencies of CFU cells enriched with different magnesium isotopes have been obtained. The observed isotope-dependent differences are explained by intracellular enzymatic ion-radical reactions which are magnetic field and nuclear spin sensitive. Enzymatic synthesis of ATP is considered as the most probable magnetosensitive biochemical process in vivo as far as effectiveness of ATP production is concerned; it determines the viability of cells and was shown in vitro as a nuclear spin-dependent reaction. Bioelectromagnetics. 38:581-591, 2017. © 2017 Wiley Periodicals, Inc.

Enzymatic mechanisms of biological magnetic sensitivity.

Primary biological magnetoreceptors in living organisms is one of the main research problems in magnetobiology. Intracellular enzymatic reactions accompanied by electron transfer have been shown to be receptors of magnetic fields, and spin-dependent ion-radical processes can be a universal mechanism of biological magnetosensitivity. Magnetic interactions in intermediate ion-radical pairs, such as Zeeman and hyperfine (HFI) interactions, in accordance with proposed strict quantum mechanical theory, can determine magnetic-field dependencies of reactions that produce biologically important molecules needed for cell growth. Hyperfine interactions of electrons with nuclear magnetic moments of magnetic isotopes can explain the most important part of biomagnetic sensitivities in a weak magnetic field comparable to the Earth's magnetic field. The theoretical results mean that magnetic-field dependencies of enzymatic reaction rates in a weak magnetic field that can be independent of HFI constant a, if H << a, and are determined by the rate constant of chemical transformations in the enzyme active site. Both Zeeman and HFI interactions predict strong magnetic-field dependence in weak magnetic fields and magnetic-field independence of enzymatic reaction rate constants in strong magnetic fields. The theoretical results can explain the magnetic sensitivity of E. coli cell and demonstrate that intracellular enzymatic reactions are primary magnetoreceptors in living organisms. Bioelectromagnetics. 38:511-521, 2017. © 2017 Wiley Periodicals, Inc.