The cell number of Saccharomyces cerevisiae can be determined by measuring the absorbance, the so-called optical density. The metabolic activity can be estimated on the basis of the CO2 release and the pH value of the media. A high CO2 release and a low pH value indicate a high metabolic activity.
Eight flasks were filled with 10 ml culture medium and inoculated with a cell suspension. Every two hours in four flasks the biomass growth and in the other four flasks the CO2 pressure was measured. The pH value was determined at the beginning and at the end of the experiment. The cell cultures were exposed or sham exposed at 110 mT or 220 mT.
|Setup||round permanent NdFeB magnets were inserted into an Isopor polyurethane foam plate; to achieve the 220 mT static magnetic field two magnets were inserted into the plate at each side of the flasks; the 110 mT static magnetic field was obtained by placing one magnet into a fitting round shaped slit just under the center of the flasks|
|Sham exposure||A sham exposure was conducted.|
In the 220 mT exposed group, a slightly increased biomass growth was observed and the CO2 pressure was increased in comparison to the control group and the 110 mT exposed group after 12 to 24 hours. The pH value at the end of the experiment was lower in the 220 mT exposed group when compared to the control group and the 110 mT exposed group.
The authors conclude that the observed alterations in the 220 mT exposed group were provoked by an enhancement in the cellular metabolic rate.