Regulatory function of organic carbon supplementation on biodiesel production during growth and nutrient stress phases of mixotrophic microalgae cultivation

Critical role of organic carbon supplementation on the lipid synthesis during growth and nutrient deprived stress phase was investigated in present study. Mixotrophic cultivation showed relatively higher biomass productivity at lower carbon loading condition (500 mg COD/l). Nutrient deprivation induced physiological stress and glucose supplementation with 2000 mg COD/l supported higher lipid accumulation (26%). Glucose supplementation in mixotrophic growth phase showed distinct influence on biomass growth whereas glucose supplementation in nutrient starvation resulted in higher lipid storage. Compositional variation in FAME profile was observed with respect to saturated fatty acids when operated with increasing glucose concentrations. Mixotrophic mode of cultivation showed remarkable benefits of nutrient removal and organic carbon supplementation influenced greatly on biodiesel production which can be easily scaled up to pilot plant and large scale production facilities. (C) 2014 Elsevier Ltd. All rights reserved.