Membrane Lipids and Osmolytes Composition of Xerohalophilic Fungus Aspergillus penicillioides during Growth on High NaCl and Glycerol Media
О. А. Данилова, Elena A. Ianutsevich, С. А. Бондаренко, А. Б. Антропова, В. М. Терешина
Abstract
Abstract Aspergillus penicillioides may be both xerophilic and halophilic. To study whether there is a difference in the mechanisms of adaptation to low water activity and high NaCl concentration the composition of osmolytes and lipids was analysed during growth on two media with 2 M NaCl or 4 M glycerol. Glycerol was the predominant osmolyte of the fungus mycelium grown on both media at all growth stages. On the medium with glycerol, the fungus accumulated twice as much glycerol as on the medium with salt. The proportion of erythritol, arabitol and mannitol was significantly higher on a medium with salt (up to 30% of the total). It was first shown that phosphatidic acids, along with sterols, were the predominant membrane lipids, while phosphatidylcholines and phosphatidylethanolamines, typical for most fungi, were minor. The general pattern of changes in the membrane lipid composition on both media during growth was the increase in the proportions of sterols and unidentified lipid X1 along with the decrease of phosphatidic acids and cardiolipins, but the changes on the salt medium were more pronounced. The degree of phospholipid unsaturation decreased only on the medium with glycerol. The results obtained show main patterns and differences in the mechanisms of adaptation of fungus to low water activity and high salt concentration.