Altered Sensitivity to UV Light and Radiation in Bacillus Bacteria Exposed to a Hypomagnetic Field

The conducted work resulted in obtaining data on the modulating effect of the hypomagnetic field (HMF) when bacterial cells are exposed to ultraviolet or radiation. After exposure to physical stress factors, bacterial spores were restored in a hypomagnetic chamber (HMC), which allows weakening the Earth’s magnetic field by almost 1000 times. The obtained results demonstrate increased survival, formation of larger colonies on a nutrient medium when restoring cells under HMF conditions after exposure to ultraviolet or radiation. Consequently, there is a higher rate of growth and reproduction of the bacterial population under hypomagnetic conditions. At the molecular level, an increased level of expression of genes involved in DNA reparation and response to oxidative stress was observed, which can provide a higher rate of restoration of damage accumulated in bacterial cells after exposure to pulsed ultraviolet or radiation. It was found that under GMF conditions, genes of the non-homologous end joining (NHEJ) and excision repair (BER) repair systems, the antioxidant enzyme catalase were activated, but the expression of genes involved in the SOS response was reduced. Despite the fact that GMF itself did not have an obvious effect on the viability of bacterial cells, it clearly increased their ability to recover after exposure to ultraviolet or radiation. The presented results indicate the role of a hypomagnetic field as a modulator of stress responses in microorganisms, which is important for understanding the possibility of their survival and adaptation in extreme space conditions.