Fatty acids profiling: A selective criterion for screening microalgae strains for biodiesel production

• Discrimination of algal strain for biodiesel production based on the fatty acid profile patterns
• A novel quality index describing biodiesel combustion characteristic and oxidative stability
• Isolation of two Persian Gulf strains and investigation of their free fatty acid profiles
• A new media formulation for simultaneous cultivation of both cyanobacteria and eukaryotic algae
• Bioprospecting-based Cloud Point measurement for algal biodiesel for the first time

The type and amount of lipids produced by an algal species directly influence the quality of the achieved biodiesel. This study is the first to report on the isolation process and lipid profile analysis of algal strains obtained from the Persian Gulf as well as 9 previously introduced strains. Biomass productivity and lipid productivity seemed to be adequate criteria for estimating the potential of different microalgae species for producing biodiesel. A principal component analysis (PCA) was applied to the estimated properties of biodiesel and the results obtained were plotted against lipid productivity. This led to the distinction of five different microalgae groups in regard to their potential for biodiesel production. This analysis also highlighted the dependence of the fuel properties on oil saturation level. On that basis, Amphora sp. and the two locally isolated strains (Dunaliella sp.) formed the extreme groups. The other three groups generated biodiesel of intermediate quality. The highest volumetric lipid productivity (79.08 mg l− 1day− 1) was found in Chlorella vulgaris. Based on the results of bioprospection by FAME profiling, the best approach for obtaining quality algal biodiesel is to mix the oils of distinct cell cultures or to specifically select proper microalgal strains for different climate conditions.