Increased lipids production of Nannochloropsis oculata and Chlorella vulgaris for biodiesel synthesis through the optimization of growth medium composition arrangement by using bicarbonate addition

Chemical Engineering Department, Faculty of Engineering, University of Indonesia, Kampus Baru UI, Depok, West Java, 16424

^* Corresponding author: danti@che.ui.ac.id

Abstract

Chlorella vulgaris and Nannochloropsis oculata are a highly potential microalgae to be used in pilot-scale of biodiesel synthesis. The essential content from these microalgae is the fatty acid of lipid which is the main target for the feed and biodiesel industries. One of the key factor in improving lipid microalgae are the arrangemment of nutrients in the growth medium. Research on the regulation of nutrients using bicarbonate (HCO₃-) as an additional inorganic carbon source has been done by many studies, but the yield of lipids obtained has not been much. The aim of the study was to improve the lipid yield of Chlorella vulgaris and Nannochloropsis oculata. Variation of [HCO₃-] which added to Walne medium were 25 ppm and 75 ppm, while the Walne medium without the addition of bicarbonate acts as control. The results showed that [HCO3-] 75 ppm could increase Chlorella vulgaris biomass by 0.9162 g/l with 17.0% wt, while Nannochloropsis oculata produced the greatest lipid content in [HCO₃-] 25 ppm of 20.3% wt and the largest biomass on [HCO₃-] 75 ppm of 1.7233 g/l.