Enhanced CO2 sequestration by a novel microalga: Scenedesmus obliquus SA1 isolated from bio-diversity hotspot region of Assam, India

The present study aimed to isolate a high CO2 and temperature tolerant microalga capable of sequestering CO2 from flue gas. Microalga strain SA1 was isolated from a freshwater body of Assam and identified as Scenedesmus obliquus (KC733762). At 13.8 ± 1.5% CO2 and 25 °C, maximum biomass (4.975 ± 0.003 g L−1) and maximum CO2 fixation rate (252.883 ± 0.361 mg L−1 d−1) were obtained which were higher than most of the relevant studies. At elevated temperature (40 °C) and 13.8 ± 1.5% CO2 maximum biomass (0.883 ± 0.001 g L−1) was obtained. The carbohydrate, protein, lipid, and chlorophyll content of the CO2 treated SA1 were 30.87 ± 0.64%, 9.48 ± 1.65%, 33.04 ± 0.46% and 6.03 ± 0.19% respectively, which were higher than previous reports. Thus, SA1 could prove to be a potential candidate for CO2 sequestration from flue gas as well as for the production of value added substances.