Lipid composition of the acidophilic alga Dunaliella acidophila (Volvocales, Chlorophyta) I. Non-polar lipids

The non-polar lipids of Dunaliella acidophila, an acidophilic green alga growing at pH 0.2-2.5, consist predominantly of fatty acids (14% of ethyl ether extract). The major fatty acids present are: linolenic, γ-linolenic, linoleic, oleic, elaidic. Three hydroxy fatty acids, which have never been detected in other algae, have been identified as methyl esters: methyl (12R)-hydroxyoctadeca-9Z,13E,15Z-trienoate, methyl (9S)-hydroxyoctadeca-10E, 12Z,15Z-trienoate and methyl ricinoleate. The triacylglycerols (5.2% of ethyl ether extract) are trilinolenin, triolein, trielaidin, tristearin. The following major carotenoids (1.4% of ethyl ether extract) have been isolated: α-carotene, β-carotene, γ-carotene, lycopene. The sterols (6.4% of ethyl ether extract) β-sitosterol, isofucosterol, 24-methylenlophenol have been detected beside (24S)-methyllophenol, isolated for the first time in green algae, and two unidentified sterols. Other lipids identified are acylsterols (5.4%) and phytol (6.4%). From the comparison with Cyanidium caldarium, a well-known acidophilic alga, no common features in terms of lipids correlated with an acid pH were evident. The possible economic utilization of D. acidophila as a producer of useful lipids is suggested. © 1988