Improvement of fatty acid composition by a strain of Chaetoceros sp. isolated from Moroccan seawater of Sidi Moussa for biodiesel production

Microalgae have many characteristics that make them an excellent choice for use as a renewable energy source. Many recent studies have focused on obtaining lipids from microalgae, by stress conditions such as reducing the availability of nutrients in culture media, particularly nitrogen and phosphorus. This is a key step in the production of biodiesel feedstocks from microalgae that needs to be better understood. In this study, a strain of Chaetoceros sp. isolated from seawater off Morocco was investigated under different concentrations (0%, 50%, 100%, and 150%) of nitrogen and phosphorus for accumulation of fatty acids. Cell growth was observed over the course of 14 days, resulting in a final cell density of 1.03 x 10(7) cells mL(-1) in the nitrogen starvation medium, with an initial NaNO3 concentration of 112.5 g L-1 and a maximal lipid level of 29.9% when subjected to complete nitrogen deprivation. For a 7.50 g L-1 initial NaH2PO4 concentration in the culture medium, a maximum cell density of 1.07 x 10(7) cells mL(-1) was achieved with 21.82% lipid yield in the absence of phosphorus. According to these findings, a high concentration of phosphate and nitrate sources aided in the concentration of biomass. The current study also shows that, as the medium's phosphorus or nitrate content falls, the lipid content increases. Nutrient stress for Chaetoceros sp. cultivation was found to have a significant impact on biomass and lipid accumulation. It is suggested that wastewater with limited nutrients could be used as a medium for growth to stimulate lipid accumulation in this microalgae.