Microalgae are rich in valuable metabolites have high potential for various number of applications. Many microalgae species accumulate substantial amounts oil under environmental stresses presumably by channelling the photosynthesis products originally allocated to support cell division and growth production energy-rich storing molecules triacylglycerol (TAG). Nitrogen phosphorus essential nutrients cultivation. limitation sodium bicarbonate supplementation culture medium is always associated with influences fatty acid composition microalgae. This study demonstrated Messastrum gracile a rarely studied microalga productions nitrogen phosphate deficient excess conditions besides medium. Metabolite profile both aqueous organic extracts were evaluated at different salinity stress. Fatty was assessed gas chromatography (GC) expression levels Streoyl-ACP desaturase (SAD) omega-6 (?-6 D) omega-3 (?-3 genes determined real-time PCR. properties stages stress also NMR spectroscopy. Significant increases total content observed nitrate limited cultures. The showed tolerance towards wide range concentrations concomitant double palmitic (C16:0) oleic (C18:1) acids. Both acids together contributed between 81-87% content. nitrate-and phosphate-deficient condition up-regulated involved biosynthesis monounsaturated (MUFA) polyunsaturated (PUFA) Increased accumulation PUFAs expense saturated (SFAs) particular C16:0 These results rendered insight into understanding pathway M. gracile could pave way future genetic modification enhancement its PUFA spectroscopy on crude that these dominated sugar lipids respectively. strengthen reasons this as sustainable renewable biofuel source.