Optimization of culture conditions for lipid production by microalga Asterarcys quadricellulare and evaluation of lipids for biodiesel production

Abstract

Culture conditions were optimized for lipid production in Asterarcys quadricellulare, an isolate from fresh water of Kedarnath, India. Under N limitation, biomass production decreased by 5% and the amount of lipids increased by 12% over control cultures (29% lipid content). Under continuous illumination and at pH 6.4 of the medium the biomass of the organism increased by 6% and 4%, respectively, while lipid content increased by 8% and 7%, respectively. The fatty acid profile of lipids of the organism under optimized conditions also changed. Under nitrogen limitation saturated fatty acid (SFA) content was 47%, monounsaturated fatty (MUFA) were 26% and polyunsaturated fatty acids (PUFA) were 27%; under continuous illumination SFA were 44%, MUFA were 30% and PUFA were 26% compared to control cultures with 40% SFA, 28% MUFA and 32% PUFA. This indicated that fatty acid profile of lipids under optimized conditions was better from biodiesel production point of view.