Effect of Media Composition and Culture Time on the Lipid Profile of the Green Microalga Coelastrum sp. and Its Suitability for Biofuel Production

Abstract

The development of biofuels as an alternative to the use of fossil fuels is growing worldwide due to environmental concerns and energy independence; thus, considerable technical progress has been achieved in biofuel production. Microalgae have been widely used for nutrient removal during wastewater treatment and produce compounds that can be used as feedstock for biofuel synthesis. In this work, the green microalga Coelastrum sp. was cultivated using industrial wastes: molasses as the carbon source and synthetic wastewater as the culture medium to determine the potential of its use for biofuel production. The use of synthetic wastewater (SWW) and molasses improved biomass production when compared with cultures carried out in a standard laboratory culture medium, such as tris-acetate-phosphate (TAP). Growth rates of 0.31 and 1.4 day−1 were attained during exponential growth rate with SWW and molasses and TAP media, respectively. The best results in biomass and lipid content, 2.29 ± 0.05 and 0.71 ± 0.03 g L−1, were obtained after 15 days of culture in SWW with molasses. The analysis of the lipid profile, produced by Coelastrum sp. cultured under these conditions, determined that the microalga can be considered as a high-quality feedstock for producing green diesel, bio-jet fuel, or biodiesel.