Microalgal Lipid Profile and Their Dietary Impact on <em>Drosophila melanogaster</em>

Microalgae are seen as a promising source of sustainable essential lipids for animal and human nutrition. These advantages, however, differ depending on the strain and growing conditions. Furthermore, the link between microalgae lipid profile and their effect on target organisms during dietary consumption is still not well understood. This study examined the lipid content and antioxidant properties of four microalgae strains cultured on 3N-BBM+V medium, and the effect of their dietary inclusions on the lifespan, body mass, and fertility of the common fruit fly Drosophila melanogaster. It was shown that C. vulgaris, N. limnetica, S. communis, T. obliquus exhibit total lipids at 26.7 ± 2.8%, 27.2 ± 0.9%, 16.6 ± 3.0%, and 22.6 ± 0.9% of dry biomass, respectively. All microalgal species produced unsaturated C15:0, C16:0, monosaturated C18:2n6 (omega-6), and C18:1n9 (omega-9) but at different proportions. Feeding D. melanogaster with C. vulgaris, S. communis, or T. obliquus biomass at 3 mg/mL inclusion extended the female median lifespan by 45.9%, 8.1%, and 27.0%, respectively. A more significant extension was observed for fly males, where adding biomass of C. vulgaris, N. limnetica, S. communis, and T. obliquus increased the lifespan of the flies by up to 75.0%, 25%, 29.2% and 50.0% re-spectively. The fertility of flies fed with T. obliquus and S. communis was also increased by 20% and 18% respectively. Meanwhile, no significant difference in the body mass of flies fed with microalgae was detected compared to the control.