Exploring freshwater microalgal strains for Omega-3 polyunsaturated fatty acids and carotenoids from the Ganges River in India

Abstract

Microalgae, increasingly recognized as a cost-effective reservoir of natural compounds. Their extensive application in nutraceuticals, and pharmaceuticals industry are making them mercantile worthy. This study delves into the realm of bioprospecting freshwater microalgae with focus on extracting high-value products, specifically omega-3 polyunsaturated fatty acids and carotenoids. Freshwater-derived microalgal strains were isolated from Ganges River and refined, and grown in BG-11 culture medium. Microscopic examination was used to screen these microalgae based on morphology. Subsequently, the biochemical properties of the selected microalgal strains were investigated. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), two crucial omega-3 polyunsaturated fatty acids, were identified in significant quantities in Chlorella variabilis (3.6±1.32%; 2.7±0.13%) and Monoraphidium contortum (2.2±0.36%; 3.2±0.2%). Moreover, the investigation also focused on carotenoids; lutein and astaxanthin. The findings indicated a high concentration of lutein in Chlorella variabilis (4.5 mg g−1), while Monoraphidium contortum exhibited abundant levels of astaxanthin (5.9 mg g−1). These research findings demonstrate the promising capacity of the isolated microalgal strains to yield valuable bioactive compounds.