ISOLATION AND MOLECULAR IDENTIFICATION OF TWO STRAINS OF MICROALGAE FROM SIDI AMEUR SALT LAKE IN ALGERIA

Abstract

Microalgae constitute an excellent feedstock of valuable compounds which have varied applications in the nutraceutical and pharmaceutical industries. In this study, the isolation of two microalgal strains, DunaDZ2 and DunaDZ3, from Sidi Ameur salt lake was done by streaking water on solid f/2 medium. The strains were subjected to morphological identification as well as molecular identification by sequencing genes ITS and rbcL. The strain DunaDZ2 presented a palmella stage (colonial aggregates of cells) throughout all of its life cycle (length 5.5 ± 1.8 µm and width 4.8 ± 1.2 µm). By contrast, DunaDZ3 presented ellipsoid shape of about 14.6 ± 1.7 µm length and 6.9 ± 1.3 µm width. Phylogenetic analysis based on ITS and rbcL genes revealed that both strains are members of the genus Dunaliella, and were grouped in the same clade with different strains of Dunaliella viridis (96.9 to 98.7% of similarity for ITS gene, and 96.4 to 98.1% for rbcL gene). The species Dunaliella viridis is considered as promising feedstock for applications in the production of biofuels and as a nutritive food source for aquatic organisms.