Time and Intensity of Electromagnetic waves impacts on the Growth phase of Escherichia coli bacteria

Background: Electromagnetic fields have various effects on the biochemical and cellular behavior of microorganisms due to radiation. It is necessary to investigate more extensively the effects of these magnetic fields on some microorganisms, such as bacteria. The purpose of this study was tp investigate the effects of magnetic fields on Escherichia coli bacteria (PTCC 1330). Materials and Methods: E.coli bacteria were prepared in liquid growth medium at the proper density. Then, the bacteria were placed in a magnetic field of 0, 1, 5, 10, 20, 30, 40 and 50 Hz at 0, 4, 8, 12, 16, 20, 24, 28 and 32 time intervals. Afterwards, their population was calculated, and the impact of these waves on the bacteria growth phases, based on the factorial pattern, was measured. Results: Field intensities of 1, 5, 10 and 20 Hz caused an increase in the number of bacteria cells. With increasing field intensity to 50 Hz, the growth of bacteria was reduced. Field intensities of 5, 30, 40 and 50 Hz caused an increment in the time of the lag phase, and field intensities of 1, 10 and 20 Hz caused an increment in the time of the stationary phase. At 1 to 30 Hz field intensities, the duration time of each cell division was reduced, and at 10 Hz field intensity, this reduction reached a minimum. But at a field intensity of 40 and 50 Hz, the time velocity of bacteria reproduction decreased. Conclusion: Given that E.coli bacteria is a pathogen, and at the same time a very important bacteria in scientific activities, the results of this study could be used in procedures to  increase and decrease the population of this bacteria population.