The proof of high potency of microalgae for large scale production of biodiesel could be considered as a revolution in microalgal biotechnology. Comparing to plants they have higher growth rate, higher lipid content, and lower water demand. They could also be cultivated on non arable lands using marine, brackish and salty waters. Among microalgal species, different species belonging to Dunaliella have shown good potential as a source for biodiesel production.

In this research Dunaliella salina 19/18 together with an endogenous isolate of Dunliella sp. (M1) Isolated from Maharloo lagoon in Shiraz,Iran were utilized. They were cultivated under different conditions: five different salt concentrations from 1 to 3.5 M NaCl and light intensities of 110 and 330 μmol m ^-2.s^-1. Their growth and lipid content at different conditions were measured.

The results showed that both studied microalgae have a high potency for production of lipid. Lipid content was the highest for the microalgae grown under high light intensity (330 μmol m ^-2 s^-1) and 2 M NaCl. The lipid content of D. salina 19/18 and Dunliella sp. (M1)   under above mentioned conditions were 41± 0.9 and 38± 1.2, respectively. The highest biodiesel yield for D. salina 19/18 and Dunliella sp. (M1) were 29.71% and 26.74%, respectively. The produced biodiesel was added to diesel fuel with different volume percentages and B2, B5, B10, B20 and B50 were produced. The physical characteristics of the produced blends including density, pour point, flash point, viscosity and cetane number were evaluated. Results showed better characteristics for the blends compared to the pure diesel fuel.