Fatty Acid Biosynthesis from a New Isolate Meyerella sp. N4: Molecular Characterization, Nutrient Starvation, and Fatty Acid Profiling for Lipid Enhancement

Abstract

Microalgae are considered as potential feedstock for biodiesel production. In this study, a new green microalga was isolated from a freshwater pond in India and identified as Meyerella sp. N4. Nutrient starvation strategy was employed in this strain to understand the enhancement of the lipid accumulation. The increase in accumulated lipid was further confirmed by Nile red staining, followed by confocal laser scanning microscopic observation. Nitrogen (NaNO3) starvation increased the lipid accumulation up to 60.4 ± 3.7% of dry cell weight at 314 ± 13 mg of total lipid/L in 23 days, when compared to the other conditions tested. Quantification of total fatty acid content by gas chromatography–mass spectrometry showed the presence of two major fatty acids, C16 at 34 ± 4.8 wt %, and C18:1 at 26 ± 3.6 wt %. Biodiesel quality parameters, such as cetane number at 57.7 ± 0.3, iodine value at 77.7 ± 1.1 g of I2 100 g–1 of oil, saponification value at 190.5 ± 1.8 mg of KOH g–1 of oil, and the cold filter plugging point at −1.5 ± 1.0 °C, are in good agreement with the international standards, American standard ASTM D6751 and European standard EN 14214, of biodiesel, thus making Meyerella sp. N4 a potential candidate for biodiesel production.