Chlorella sorokiniana: Effect of nitrate replete concentration on biomass yield, cell and nitrate concentration

Effects of various nitrate replete concentrations have been investigated in terms of biomass yield, cell and nitrate concentrations. Media used in this study is Bold's basal medium which contains nitrate that act as nutrient. Its concentrations have been varied for obtaining the high biomass yield. The nitrate concentrations used were 30 mg nitrate/L, 35 mg nitrate/L, 40 mg nitrate/L, 45 mg nitrate/L and 50 mg nitrate/L. Microalgae Chlorella sp. is cultured and aerated in a Schott bottle with presents of light. Results showed that the best concentration to obtain highest biomass yield was 45 mg nitrate/L. It also gave the highest optical density reading at day 9 with 2.100±0.070 and showed the highest cell concentration with 703±29 x 106 cells/mL. A dry alga produced by this concentration after the end of the cycle was 291±9 mg which was the highest compared to other concentration. It is suggested that as the biomass yield is increased by using 45 mg nitrate/L concentration, other methods to increase lipid content can be paired with nitrate replete method and can be further studied in the future. © 2019 Trans Tech Publications Ltd, Switzerland.