INFLUENCE THE PH FACTOR OF THE CULTURE MEDIUM ENRICHED WITH MAGNESIUM IONS ON THE ABILITY OF BINDING THIS ELEMENT BY THE YEAST CANDID UTILS ATCC 9950 IN DYNAMIC CONDITIONS

摘要

The research concerned the influence of the pH of the culture medium on the ability of binding magnesium ions, by the cells of Candia utilis ATCC 9950. In the same time, the influence of the active acidity of the culture medium enriched with magnesium on the cell biomass yield. For this purpose, pH of the YPD culture medium has been set on the 5.0, 6.0 and 7.0 and enriched in a constant dose of magnesium, namely 1.25 g/dm3 in the beginning of the 48 hours culture in dynamic condition. The biggest amounts of magnesium binding with the cells (4.26 mg/g d.w.) were present in the cells on the culture medium which pH factor was 7.0 after 48 hours. The biggest biomass yield in the experi-mental conditions (15.51 g d.w./dm3) was received after 24-hours culture, also on a neu-tral pH medium. It is possible that the active acidity was the factor of the environment which determined the ability of binding magnesium from the medium by regulating its accessibility for the outer structures of the yeast cells.