ACTA Scientiarum Polonorum - Technologia Alimentaria

abstract: In this research, the ATCC 9950 Candida utilis yeast strain capacity to bind the Mg2+ ions was studied. The yeast was cultivated in dynamic conditions (with aeration) in the YPD medium enriched with the MgSO4·7 H2O or MgCl2·6 H2O magnesium salts. The salts were being added in such an amount, that the Mg2+ content in the medium was 0.25 g/dm3; 0.5 g/dm3 or 1.25 g/dm3. The YPD medium was enriched with magnesium ions at the beginning of the cultivation or in the end of the logarithmic phase of yeast growth. In order to evaluate the stability of bonds of Mg2+ ions with yeast cells, the magnesium con-tent was evaluated in the centrifuged yeast biomass that had and had not been washed with deionized water. The studied strain proved its capacity of permanent bonds with magnesium ions originating from the experimental mediums. MgCl2·6H2O added to the cultivation, favoured the binding of magnesium form the YPD medium by the yeast, but MgSO4·H2O added to the cultivation allowed obtaining higher biomass yield. The largest number of magnesium binding by biomass yeast cells (9,09 mg Mg2+/g d.w.) was ob-tained from YPD medium after 48-hour cultivation with chloric salt added in the amount of 1.25 g Mg2+/dm3 in the end of the logarithmic phase of yeast growth.