Résumé
Understanding the response of microalgae to outdoor culture conditions is necessary for the development of large open pond cultivation system for various value added applications. In this context, we evaluated the response of an indigenous oleaginous green microalga Scenedesmus obtusus CFR 1-09/FW to outdoor culture conditions. The microalga was cultivated in open ponds at various culture depths under nutrient replete condition. The pond with 3 cm culture depth showed highest biomass productivity (49.05±11.74 mg L-1 day-1). The high surface solar irradiance (1831 µmol m-2 s-1) led to a decrease in chlorophyll content (from 12.21 to 4 µg mg-1). The long duration exposure to lower temperatures (≤20°C) during night led to an increase in poly unsaturated fatty acids (PUFAs) content (47.21±2.83% w/w mass fraction of FAME). The omega-3 alpha linolenic acid (ALA) content rose significantly reaching 31.01±3.79% (w/w) mass fraction of FAME. The high content of carbohydrate (23.4±0.64% w/w), protein (37.62 ± 2.15% w/w), lipid (21.55±1.43% w/w), palmitic acid (30.97±4.02% w/w mass fraction of FAME) and ALA in outdoor cultures makes this microalga a potential candidate for outdoor cultivation for food and feed applications. The study provides valuable insights for developing outdoor open pond cultivation protocol.