EFFECTS OF SALINITY, LIGHT AND NITROGEN CONCENTRATION ON GROWTH AND LIPID ACCUMULATION OF THE GREEN ALGAE DUNALIELLA BARDAWIL

Efficient biofuel production from algae depends on the microalgal biomass production rate and lipid content. Both biomass production and lipid accumulation are limited by several factors, of which nutrients play a key role. In this study, the marine microalgae Dunaliella bardawil was used as a model organism. D. bardawil was cultured at two different sodium nitrate concentrations as 0 and 0.7 M, at six different amounts of salinity as 0.65, 1.0, 1.5, 2.0, 2.75 and 3.5 M, and at two different light intensity levels as 65 and 800 mu mol foton m(-2) s(-1) The study was done under pH 7. After 15-day growth period, the most efficient culture of D. bardawil for both biomass increase and lipid production was determined for the samples with 39.67 +/- 4.51 lipid rates cultured under 0.7 M nitrate concentration, 2.75 M salinity and 800 mu mol photon m(-2) sn(-1) light intensity. This high level of lipid production is sufficient to use D. bardawil for biodiesel production. Also after the evaluation of fatty acid results of GC-FID analysis, it was determined that D. bardawil contains high rate of medium length (C16-C18) fatty acid chains suitable for the production of biodiesel. These results are satisfactory to use D. bardawil in biodiesel production.