Effective dose analysis of extremely low frequency (ELF) magnetic field exposure to growth of S. termophilus, L. lactis, L. acidophilus bacteria

摘要

The Extremely Low Frequency (ELF) magnetic field, which is a component of a non-ionizing radiation, at low intensity has been shown to increase cell proliferation. This fact is expected to lead to a technological breakthrough in S. thermophilus, L. lactis, and L. acidhopilus bacteria activation which is needed in the production process of cream cheese. The main issue considered here in the production process of cream cheese is the growth of bacteria which often cannot be optimal, causing it to taste bad. This study is an initial step to determine the effective dose of exposure to ELF magnetic fields on the S. thermophilus, L. lactis, and L. acidhopilus bacteria growth. This research used the exposure of ELF magnetic field with intensity of 100 μT and 300 μT to those three types of bacteria with exposure durations of 5, 15, 25, 35, and 45 minutes. Measurements of the amount of bacteria were performed 1 hour, 2 hours, and 16 hours after exposure to ELF magnetic field. The results of this study indicated that the growth of three types of bacteria exposed to ELF magnetic field with an intensity of 100 μT was significantly faster than the control one, but the other one which were exposed to 300 μT ELF magnetic field was not different from the control one. The analysis results provided evidence that the rate of optimal growth occurred in three types of bacteria after being exposed to 100 μT ELF magnetic fields for 5 minutes. Therefore, it could be concluded that exposure to ELF magnetic field with an intensity of 100 μT for 5 minutes is an effective dose for the activation of S. thermophilus, L. lactis, and L. acidhopilus bacteria growth.