Desiccation-induced changes in the lipid and fatty acid composition of the cyanobacterium Nostoc commune

The Lipid and fatty acid composition of cyanobacterium Nostoc commune Vauch. cells were investigated in both the hydrated and desiccated state. The amount of total lipids per dry weight basis decreased threefold with desiccation of the cyanobacterium N. commune. In this case, the content of neutral lipids, glycolipids, and polar Lipids decreased by factors of 2, 5, and 4.5, respectively. Among the neutral lipids, the level of triacylglycerols and sterol esters diminished, but that of waxes and free sterols increased. The content of both glycolipid classes, monogalactosyldiacylglycerols and digalactosyldiacylglycerols, was significantly lower in desiccated than in hydrated cells. The content of all identified individual classes of polar lipids also decreased with desiccation. The specificity of the fatty-acid composition of desiccated cells was exhibited as a considerable increase in the level of saturation for the neutral Lipids and as a certain increase in the relative content of long-chain fatty acids for the polar lipids. The possible role of these changes observed in the lipid composition of N. commune cells adapting to desiccation is under consideration.