Abstract
Microalgae as an alternative feedstock for biodiesel production has achieved attention because of increasing fuel demand, climate change as well as global warming. For this purpose, 41 local microalgae strains belonging to 5 different phyla having the capability of best survival in climatic conditions were isolated from aquatic sources. The selection of most robust strains (C. vulgaris, S. dimorphus, S. obliquus, Selenastrum sp, and C. humicola) was based on biomass and lipid productivity. The microalgae C. vulgaris had highest performance in terms of biomass in BG-11 medium (1.86 ± 0.1 g/L) as compared to wastewater (1.14 ± 0.3 g/L) followed by S. obliquus. Moreover, the highest lipid contents were obtained in heterotrophic conditions (35.1 ± 1.0%) in C. vulgaris and the overall lipid productivity was high in mixotrophic condition because of high biomass contents. The extracted oil was analyzed for fatty acid contents and the strains S. dimorphus and S. obliquus have high contents of saturated fatty acids (SFA, 63.67% and 63.60%, respectively). Whereas, C. vulgaris has high amount of monounsaturated fatty acids, saturated ones and (MUFA 81.28%) as well as low polyunsaturated fatty acids (PUFA 18.72%) are the factors that make this high quality biodiesel a strong competitor of fossil fuels.
•Isolation of 41 microalgae strains from freshwater and wastewater resources.•Top 5 isolates proved effectiveness as biomass producers in mixotrophic conditions.•Microalgae C. vulgaris had highest performance in terms of biomass in BG-11 medium.•Stearic acid (C18:0) is predominant fatty acid in most of the strains.