Growth and Lipid Production of Marine Microalgae Tetraselmis Chuii Cultured in Different Phosphorus Concentrations

Abstract

Lipid produced in the marine microalgae, Tetraselmis chuii has the potential to be processed into biofuels which can replace the use of fossil fuels that contributes to the global warming on earth. The purpose of this study was to determine the effects of phosphorus on lipid production in Tetraselmis chuii. Therefore, Tetraselmis chuii was cultured under normal concentration of phosphorus in the Conway medium. The cell was harvested on the fourth day and then transferred and cultured under different concentrations of phosphorus (10g, 15g, 20g, 25g and 30g of NaH2 PO4 .2H2 O in 1 L Conway medium). The cell density and optical density analysis of the culture were analyzed daily whereas the biomass (dry weight) analysis and lipid extractions were carried out on every alternate day. Result of the study showed that the highest lipid production in Tetraselmis chuii was achieved on day 4 in the phosphorus sufficient culture medium (25 g/L of NaH2 PO4 .2H2 O). Under the deficiency of phosphorus in the culture medium especially when the growth reached the stationary phase, more lipids accumulated in all the treatments. Therefore, our findings illustrated that phosphorus was important in regulating the growth of Tetraselmis chuii and the lipid accumulation was higher when the growth of Tetraselmis chuii was limited by the depleted phosphorus. In addition, total lipid yields also increased with the presence of excess phosphorus in the culture medium.