Cultivating microalgae, Chlorella sp. in nitrate replete concentration for biodiesel production: article / Noor Amelina Abdul Rahim and Professor Dr. Norazah Abdul Rahman

The impact of various nitrate replete concentration is investigated in terms of biomass yield, cell concentration and nitrate concentration. The media used in this study is Bold’s basal Medium as the medium contain nitrate that act as nutrient and varied for the purpose of finding best concentration to produce high biomass yield. The chemical used for the medium is fairly easy to obtained thus used as the media. The nitrate concentration is varied as 30 g nitrate/L, 35 g nitrate/L, 40 g nitrate/L,45 g nitrate/L and 50 g nitrate/L concentration. The sample is culture in Schott bottle with light presents and aerated with air compressor. The results show that the best concentration to obtain highest biomass yield is 45 g nitrate/L concentration. 45 g nitrate/L concentration gives highest optical density reading at day 9 with 2.100 ± 0.070 and also shows the highest cell concentration with 703 ± 29 x 10⁶ cells/mL. The dry algae produced by 45 g nitrate/L concentration after the end of the cycle is 291 ± 9 mg which is the highest compare to other concentration. As the biomass yield is already increased using 45 g nitrate/L concentration, other methods to increase lipid content can be pair with nitrate replete method and can be further studied in future.