In this study, three strains of lactic acid bacteria (BDU-BA7, BDU-BA8, BDU-BA9) were isolated from spontaneous sour milk products during solar flares, coronal mass ejections, and geomagnetic storms (solar wind). The influence of the geomagnetic storm on the studied strains was investigated in a comparative form. It was observed that, unlike the strains cultivated under normal weather conditions for the same period of time (5 days), as the level of the geomagnetic storm increased, during the incubation of the strains, the size of the colonies and microbial cells significantly changed and decreased. The obtained result may be important in conducting further research and using these characteristics of strains sensitive to geomagnetic storm for various purposes.