Strategy study on enhancing lipid productivity of filamentous oleaginous microalgae Tribonema

Abstract

Filamentous microalgae Tribonema is promising for biodiesel production in terms of high lipid content, easy harvesting and good contamination tolerance. As high lipid productivity is a key basis, several methods including different culture medium, phosphorus, iron and CO2 inductions were tested to enhance lipid productivity in Tribonema minus. T. minus subjected to BG11-freshwater medium achieved a favorable lipid productivity of 216.18mgL(-1)d(-1), much higher than those in other culture medium (BG11-S, Kuhl, f/2, f, 2f, BBM, ASW and ES). Secondly, the optimal phosphorus, iron and CO2 concentrations for high lipid productivity of T. minus were obtained, respectively. Finally, the cells of T. minus grown in optimized BG11 medium containing 80mgL(-1) KH2PO4 and 6mgL(-1) FeC6H5O7·NH4OH with 2% CO2 achieved a lipid productivity of 384.67mgL(-1)d(-1), representing a 1.56-fold increase from the control. Therefore, the strategy to enhance lipid productivity of T. minus was successfully proposed.

Keywords: CO(2) concentration; Iron ion; Lipid productivity; Phosphorus; Tribonema.