A NEW CULTIVATION SYSTEM OPERATED UNDER A SUPER HIGH MAGNETIC-FIELD

A new cultivation system which operates under a super high magnetic fi eld in the range of 0.5 to 7 Tesla was developed. In this reactor syst em, the effects of a high magnetic field on various biological reactio ns could be investigated not only under a homogeneous high magnetic fi eld, but also under a gradient magnetic held. The maximum magnetic fie ld gradient is 23 Tesla/m. Since the superconductive magnet was design ed so as to significantly reduce the evaporation rates of liquid heliu m and nitrogen, operation is virtually maintenance-free compared with that in conventional superconductive magnets. The temperature of the r eactor is controllable within the range of 10 to 70 degrees C (deviati ons of +/- 0.1 degrees C). When Escherichia coil B cells were grown at 37 degrees C, total cell number during the stationary phase was 70% h igher under homogeneous 7 Tesla conditions than in the geomagnetic fie ld. A three fold larger cell number was detected in a gradient magneti c fields between 5 and 6 Tesla.