The Proliferation of Saccharomyces Cerevisiae Exposed to Pulsed Magnetic Fields of Low Intensity Suggests the Presence of a Frequency Window between 20 Hz and 77.5 Hz

Cultures of yeast Saccharomyces cerevisiae were exposed to pulsed magnetic fields of low intensity. Field intensities from 0.92 mT to 2.73 mT and frequencies of 20, 77.5, 135, 192.5 and 250 Hz were employed. Proliferation and cell viability measurements were made in exposed cultures and the results were compared with control cultures. For the frequency of 20 Hz, statistically significant differences were found (p <; 0.001) in cell proliferation using field intensities of 1.81 and 2.71 mT. No changes were observed at this frequency for lower field strengths. At 77.5 Hz, only changes in proliferation were observed for 0.92 mT. No changes were observed to any other frequency or intensity of the magnetic field. The cell viability studies were performed at different times, from 4 to 12 hours of exposure. At 1.81 mT and 20 Hz, an increase in colony forming units (CFU) of 26.1% was observed (p <; 0.001) at 4 hours, and after 10 hours of exposure the increase in CFU was 51.5% (p <; 0.024). But when exposing the cells for 9 hours to a magnetic field of 2.71 mT at 20 Hz the CFUs decreased by 25.9% (p <; 0.003). These results suggest the presence of a frequency window between 20 Hz and 77.5 Hz where the effects of the field are important.