The role of operating temperature as a physical stress factor for enhancing lipid induction during microalgae
cultivation with domestic wastewater was evaluated. Experiments were designed with dual mode
microalgae cultivation viz., growth phase (GP) and temperature induced stress phase (25 C, 30 C and
35 C). GP showed enhancement in biomass growth and carbohydrate accumulation while stress phase
(SP) operation at 30 C showed noticeable improvement in lipid productivities (total/neutral lipid,
24.5/10.2%). Maximum carbohydrate utilization was observed during SP at 30 C operation (57.8%) compared
to 25 C (50.6%) and 35 C (26.9%) correlating well with the lipid synthesis. Interestingly the neutral
lipid content documented five-fold increment illustrating feasibility towards good biodiesel properties.
Biodiesel profile at 30 C temperature is well supported by higher saturated fatty acids (SFA) to unsaturated
fatty acids (USFA) ratio. GP operation showed good COD and nutrient removal concomitant to the
biomass growth.
2014