Abstract
Biodiesel production from three local microalgae from Egypt was investigated. These microalgae strains differ in their growth pattern as one of the cyanobacterial strains is filamentous mat-forming Phormidium sp. whereas the other strain is coccoid colony-forming Microcystis sp. The third is coccoid yellow-green Botrydiopsis sp. The mass productivity for the strains in a photobioreactor using semi-continuous culture was arranged as: Microcystis sp.> Botrydiopsis sp.> Phormidium sp. The mass productivity can be increased by increasing the illumination period in case of Botrydiopsis sp. and Microcystis sp. The lipid content was determined by using different solvents for lipid extraction. The Botrydiopsis sp. gave the highest lipid content (48%) for Botrydiopsis sp. cultured in Oscillatoria medium. Microcystis sp. had (28%) lipid content while the Phormidium sp. had the lowest lipid content (15%). The major components of the fatty acid compositions in different algal species studied were linoleic, palmitic, oleic and stearic. In conclusion, the cultivation of microalgae in photo-bioreactor has given high biomass productivity by applying semi-continuous feeding technique. The highest mass productivity doesn't mean the highest lipid content. The Gas chromatography analysis showed that the algae oils have the suitable fatty acid composition for biodiesel production.