Isolation of prospective microalgal strains with high saturated fatty acid content for biofuel production

Isolation of new microalgal strains with unique and valuable properties from diverse environmental conditions is an important starting point for the establishment of high quality feedstock for biofuel production. In this study, we have isolated twelve strains of microalgae, belonging to the genera Chlorella, Botryococcus, Scenedesmus, Nannochloris and Bracteacoccus from samples obtained from various natural sources by flow cytometry. Five of them were selected for further evaluation, as lipid producers on the basis of Nile Red fluorescent microscopy screening. Analysis of the biomass in the exponential and stationary phases of growth showed that the strain Scenedesmus abundans A1175 has the highest specific growth rate (0.20 ± 0.01 d−1), biomass productivity (73.82 ± 4.53 mg L− 1 d− 1) and lipid content (44.4 ± 2.7%) in nitrogen depleted conditions. Strains Chlorella vulgaris A1123 and S. abundans A1175 have a high total content of saturated (SFA) and monounsaturated (MFA) fatty acids (67.0% and 72.8% respectively). S. abundans A1175 also had low polyunsaturated fatty acid (PUFA) content that would allow for its use as a source of high quality biofuels.