Lactobacillus gasseri Growth after Microwave Irradiation

Abstract

Lactobacillus gasseri is a bacteria found in the gastrointestinal tract and vagina, and is essential for digestion and absorbing important nutrients. Some studies have experimented to find the effect of pulsed 2.4-GHz microwave irradiation on the growth of various Lactobacilli strains, while others have used continuous radiation at a similar frequency. Different studies have concluded that such radiation could kill other gut bacteria like Escherichia coli. We tested the effect of continuous microwave irradiation on the growth of Lactobacillus gasseri. We first irradiated four groups of the bacteria with a 10.5-GHz microwave transmitter for different amounts of time (0 minutes, 10 minutes, 20 minutes, 30 minutes). There was a significant difference between the control group and each irradiated group. There was no significant difference between the three irradiated groups. Our results agree with past research that has studied the effect of both microwave irradiation and radiation on Lactobacillus. We may have found such results because the electric field created by microwave radiation can disrupt the function of oxidative defense. This defense is needed to counteract oxidative stress, which could damage bacterial cell DNA, causing cell death. Therefore, microwaves at frequencies capable of penetrating the human body could cause the inactivation of multiple gut microbiota.