Excretion products of algae and their occurrence in Solar Lake. Taba, Egypt

The present study aimed to investigate the nature of organic compounds liable to be released by blue-green algae (cyanobacteria) and organic compounds detected in the Solar Lake in Taba, Egypt. The liquid-liquid extraction method and liquid chromatography technique were applied for extraction, clean-up and separation of the organics. Gas chromatography/mass spectrometry (GC/MS) was used to carry out qualitative analysis. The most dominant species in the algal samples collected from Solar lake in Taba are Aphanotheca stagnina, Synechococcus aeruginosus, Oscillatoria limnetica and Microcoleus chthonoplastes. n-Alkane hydrocarbons that ranged from C-12 to C-25 were identified in lake water samples, most of them were derived from algal species. Several fatty acids were isolated from water samples with predominant tridecanoic acid (C-13), tetradecanoic acid (C-14) and hexadecanoic acid (C-16) Meanwhile, the identification of fatty acids from algal suspension samples indicated the predominance of hexadecanoic acid (C-16) and heptadecanoic acid (C-17), with carbon number that ranged from C-10 to C-17. The dominant compounds were C-15, C-17, C-17:1, C-19 n-alkanes. C-13, C-15, C-16 fatty acids, alkyl esters of propyl decanoate, esters of benzenedicarboxlate, diphenyl amine, geosmin and 2-methyl isoborneol (2-MIB) in water and in algal suspension samples were probably enough to distinguish the cyanobacterial mat community of a saline lake shore.