Comparative study of lipid composition of two halotolerant alga, Dunaliella bardawil and Dunaliella salina

The composition of polar, neutral and glycolipid fractions of two halotolerant algae, Dunaliella salina and Dunaliella bardawil, which are exclusively used for the production of beta-carotene was determined in modified medium. In D. salina the glycolipid fraction accounted to 28%, in comparison with 40% of D. bardawil. However, in D. salina the polar lipid was 42% compared with D. bardawil at 24%. The glycolipid fraction of D. bardawil was rich in linolenic acid (81%). In both the species we could find elongation in the fatty acids from C-16 to C-20 to C-22 and the percentage was higher than the earlier reports ( > 3%). The polar lipid fraction was composed of ( in descending order) phosphatidyl glycerol, phosphatidic acid, phosphatidic ethanolamine, phosphatidyl choline and phosphatidyl glycerol and the neutral lipid fraction, which was rich in monoglycerides and diglycerides and diacylglycero-trimethylhomoserine.