Effect of nitrogen limitation on growth, biochemical composition, and cell ultrastructure of the microalga Picocystis salinarum

In recent years biodiesel production has attracted worldwide attention due to the awareness of fossil fuel depletion and microalgae biomass is considered a promising raw material for its formulation. The present study evaluated effects different levels nitrogen limitation (37.5, 18.75, 9.375 mg L−1 NaNO3) on growth, cell ultrastructure, biochemical composition halophilic native strain green alga Picocystis salinarum as potential source biodiesel. During culture period 20 days, growth measurements photosynthetic pigments were estimated. Cell density, dry weight, chlorophylls a, b content decreased with time increase; however, carotenoid increased. addition, caused an progressive increase in lipid carbohydrate yield decrease protein. high N (9.375 L−1) had significant effect accumulation total (33.87% weight). Carbohydrate (30.98% weight) protein (1.89% decrease. showed differential FAME profile saturated fatty acid values (996.08 μg g−1 mainly palmitic acid, compare unsaturated ones that low under limitation. gradual was also corroborated by transmission electron microscopy images single large droplet formation. Therefore, evaluation algal conditions such limitation, strategy maximize improve unexplored P. salinarum, suitable candidate production.