Selection of elite microalgae for biodiesel production in tropical conditions using a standardized platform

Four thermotolerant microalgae were isolated from tropical Taiwan and classified as members of Desmodesmus based on morphological and molecular studies. A platform was established to evaluate their biodiesel production-related traits, including thermotolerance, lipid productivity, lipid oxidative stability and auto-sedimentation. The findings demonstrated thermotolerance of all four species was at the same level, as all could live at 45 °C for 24 h and 50 °C for 8 h with mortality rates below 5% of cells. The lipid productivity of Desmodesmus sp. F2 reached 113 mg/L/d. Its saturated and monounsaturated fatty acids accounted for 75% of the FAMEs, and it required only 3.1 h to achieve 85% sedimentation. Comparing these traits to those of the other three Desmodesmus and microalgae in the literature, Desmodesmus sp. F2 is one of the best candidates for biodiesel production in tropical and subtropical areas. This platform effectively assessed traits of microalgae related to biodiesel production.