Freshwater green algae (Scenedesmus bujugatus) were grown in batch cultures at different nitrogen levels. Freshwater green algae were grown at different nitrogen levels (0.5g/L to 1 .Og/L) at 26°C in a sterile condition. Algal samples were collected when it reached its stationary phase and analysed for protein, lipid, and carbohydrate and growth rate. Addition of nitrogen source led to an increase in the biomass (from 1 to 3 g/L), protein content (38 to 46 %), carbohydrate (7-18 %) and lipid (20 to 55 %). At low nitrogen levels, the green algae contained a protein (42 %), lipid (55 %) and carbohydrate (11 %). The algae did not show any increase in their biomass, lipid and protein compositions, when the nitrogen concentrations in the nutrient medium was increased above 1.0 gm/L. Thus the green algae can be grown under increasing nitrogen level to yield high biomass, lipid and protein compositions.

Keywords : Freshwater algae, Scenedesmus bujugatus, Bold basal medium, biomass, lipid, protein and carbohydrate.