Impact of magnesium and mannose in the cultivation media on the magnesium biosorption, the biomass yield and on the cell wall structure of Candida utilis yeast

摘要

Binding capacity of Mg2+ ions, the biomass yield and the cell wall structure of Candida utilis ATCC 9950 cultivated in the media containing magnesium and mannose were evaluated in the study. Mannose has been added to two types of culture media: not enriched and enriched with Mg2+ ions. The YPD medium was used as a control while the experimental media (without or with Mg2+ ions) have been prepared by replacing glucose in the YPD medium by 1% (YPDM) or 2% (YPM) of mannose. The highest content of magnesium (5.39 and 5.42 mg/gd.w.) as well as the highest biomass yield (15.22 and 14.03 gd.w./L) were observed after 24 h of cultivation in the media enriched with magnesium and supplemented with mannose. The yeast cultivated for 48 h in those media were also characterized by thicker cell walls (74.3 and 67.7 nm). Introduction of mannose to the cultivation media was the factor that has influenced biosorption of magnesium ions as the result of twofold thickening of the mannoprotein layer of the cell wall of Candida utilis ATCC 9950 yeast.