EFFECT OF HIGH MAGNETIC-FIELD ON MICROBIAL ACTIVITIES MEASURED UNDER A NEWLY CONSTRUCTED SUPERCONDUCTING MAGNET BIOSYSTEM

A newly constructed superconducting magnet biosystem (SBS) consists of a magnet and a bioreactor. The magnet produces high magnetic flux in the range of 0.5-7 T. The homogeneous magnetic field region covers an area of 10 cm in diameter and 20 cm long. In the region outside, the d ecrease in the magnetic field occurs at the maximum gradient of the fl ux, 23 T/m. The bioreactors are set up in both the magnetic area and t he control area and the temperature of the reactors is controlled to b e within +/- 0.1 degrees C. The bacterial mutants with several repair deficient systems and fruit-fly with a similar repair deficient system were cultivated in the SBS of homogeneous 7 T and no enhancement of t he death rates was observed, indicating that the DNA of these cells is not affected by the magnetic flux. When two bacteria were cultivated in SBS under a homogeneous 7 T field, 5-6 T inhomogeneous field and 3. 2-6.7 T inhomogeneous field, the cell number in the declining phase in high magnetic fields was always higher than that in the geomagnetic f ield, indicating that the cells when the nutrients were exhausted were sensitive to the high magnetic field.