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 degrees 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 degrees 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. (C) 2013 Elsevier Ltd. All rights reserved.