Temperature modulation of fatty acid profiles for biofuel production in nitrogen deprived Chlamydomonas reinhardtii

This study investigated the changes in the fatty acid content and composition in the nitrogen-starved Chlamydomonas reinhardtii starchless mutant, BAF-J5, grown at different temperatures.The optimal temperature for vegetative growth under nitrogen sufficient conditions was found to be 32 °C. Shifting temperature from 25 to 32 °C, in conjunction with nitrogen starvation, resulted in BAF-J5 storing the maximum quantity of fatty acid (76% of dry cell weight). Shifting to temperatures lower than 25 °C, reduced the total amount of stored fatty acid content and increased the level of desaturation in the fatty acids. The optimal fatty acid composition for biodiesel was at 32 °C. This study demonstrates how a critical environmental factor, such as temperature, can modulate the amount and composition of fatty acids under nitrogen deprivation and reduce the requirement for costly refining of biofuels.

► Algae often produce higher levels of polyunsaturated fatty acids than is desirable for biodiesel. ► Temperature shifts can alter the fatty acid profile of storage lipids under nitrogen starvation. ► 32 °C was the optimal temperature for fatty acid content and composition for biodiesel production. ► Carbohydrate and lipid storage were both affected by shifting temperature. ► Environmental factors can manipulate algal feedstocks potentially reducing the refining cost.