Increasing the cell productivity of mixotrophic growth of Spirulina sp. LEB 18 with crude glycerol.

This study investigated the growth of microalgae Spirulina sp. LEB 18 in medium supplemented with crude glycerol to evaluate the biochemical composition of the biomass and its productivity during 72 h of culture. The microalgae cultivated in medium supplemented with 2.5 g L⁻¹ glycerol presented a fourfold higher cell productivity (28.04 mg L⁻¹ h⁻¹) than the control culture, reaching a maximum biomass concentration of 1.08 g L⁻¹ in 36 h. Among the evaluated compounds, proteins were predominant in the biomass throughout the crop, and at the highest concentration of biomass (36 h), the yield was 384.15 mg L⁻¹. The composition of unsaturated fatty acids increased approximately twofold with the organic carbon source (493.53 mg g⁻¹) compared to the control. The predominant fatty acid was oleic acid, reaching 336.00 mg g⁻¹, in the culture supplemented with glycerol. The increase in productivity provides a cost reduction and increases the feasibility of obtaining microalgal biomass products, including biofuels. [ABSTRACT FROM AUTHOR]