Determination of the fatty-acid composition of four native microalgae species

In this study, two green (Chlorella sp. and Ankistrodesmus sp.) and two blue-green (Oscillatoria sp. and Chroococcus sp.) species of microalgae, which were obtained from a native microalgae culture collection from Turkey, were cultivated and investigated via capillary GC to determine their fatty-acid profiles. Growth media were chosen with consideration of the biological properties of each algae species. Our results, as well as other published data, show that fatty-acid composition offers discriminating features that allow the chemotaxonomic classification of these algae. Fatty-acid profiles and lipid contents in microalgal biomass varied between species. The microalgae containing the highest proportion of lipid in its biomass was in Chroococcus sp. (1.72%), while that containing the lowest was Ankistrodesmus sp. (0.14%). The major fatty acids in Chlorella sp. were C18:0 (26.70%), C18:1 (23.48 ± 0.0005%) and C16:0 (21.05%). C18:1 was the major fatty acid in the other three species of microalgae: Ankistrodesmus sp. (36.83 ± 0.0007%), Oscillatoria sp. (38.51%) and Chroococcus sp. (47.96%). EPA, a nutritionally important polyunsaturated fatty acid, was not observed in Chlorella sp. but was detected in Ankistrodesmus sp., Oscillatoria sp. and Chroococcus sp. at proportions of 0.35%, 0.30% and 0.62%, respectively.  In addition, another essential PUFA, DHA, was observed in all microalgae species in varying amounts.