Lactobacillus acidophilus and lactobacillus casei exposed to wi-fi radiofrequency electromagnetic radiation show enhanced growth and lactic acid production

Abstract

Background: Lactobacillus acidophilus and Lactobacillus casei are gram-positive probiotics and members of the genus Lactobacillus. These bacteria are widely appli-cable in food and dairy industries. Increasing bacterial load and decreasing fermenta-tion time make them more profitable for manufacturers. Objective: This study was aimed at assessing the biological effects of short-term exposure of L. acidophilus and L. casei to 2.4 GHz Wi-Fi radiofrequency electromagnetic fields (RF-EMF) generated by a Wi-Fi router on the lactic acid production and proliferation of these probiotic bacteria. Material and Methods: This experimental study was performed on pure culture strains of L. acidophilus and L. casei, first direct vat sets (DVS) were acti-vated in MRS broth for 24 hours then transferred to new culture mediums. Afterward, these mediums were exposed to RF-EMF for 15, 30, 45 and 60 minutes. The control samples were sham-exposed. After 72 hours of incubation on MRS agar cell counts were enumerated. Results: Exposure for 30, 45 and 60 minutes significantly increased the growth of L. acidophilus and L. casei. No difference was found between the growth of the samples exposed to RF-EMF for 15 minutes compared to that of sham-exposed bac-teria. In addition, lactic acid concentration in L. acidophilus medium was amplified after 15, 30 and 45 minutes of exposure. However, in L. casei samples, only 30 and 60 min exposures could stimulate the production of lactic acid. Conclusion: L. acidophilus and L. casei probiotic bacteria exposed for a short time to radiofrequency electromagnetic radiation (RF-EMF) generated by a widely used commercial Wi-Fi router show significantly increased proliferation and lactic acid production.