Microalgae were isolated, identified, and cultivated for enhanced biomass production and lipid accumulation. A marine microalgae was isolated from coastal rock pools of Tuticorin, Tamil Nadu, and identified as Nitzschia sp. RRSE2 upon microscopic examination and molecular sequence analysis. The experimental results showed that the maximum growth, biomass, and lipid content were obtained at pH 8 using the F/2 medium. These parameters revealed a notable difference when NaCl was added at 3% concentration. Meanwhile, the nutrients NaNO3 (18.75 mgL-1) and NaH2PO4 (3.48 mgL-1) were shown to be suitable nitrogen and phosphorus sources, respectively, for the production of lipids. On day 14, the maximum lipid concentration of 77.5 mgL-1 was produced using optimized culture conditions. Additionally, the maximum number of 17×105 cells mL-1 and the biomass concentration of 0.69 gL-1 were achieved on this same day. Finally, the fatty acid composition of the algal lipid was analyzed by gas chromatography/mass spectrometry (GC/MS) analysis.