The present study was conducted with microalga Nannochloropsis sp. to evaluate its tolerance responses and biofuel perspectives under different arsenic regime (0-1000 mu M As(III)). Results showed that optimal biomass (61.00 +/- 3.72 mg/L/d) and lipid productivity (20.27 mg/L/d) were obtained in culture treated with 100 mu M As(III) in comparison to other treatments. In addition, fatty acid profile of alga was in accordance with European biodiesel standards (EN 14214), which reflects good oxidative stability of oil. High antioxidants viz., ascorbic acid, GSH and cysteine tolerance responses as well as lipid yield at 100 mu M As (III), opens a new insight in the field of algal biology. Thus, microalgae Nannochloropsis sp. may be employ in remediation as well as biodiesel production. (C) 2016 Elsevier Ltd. All rights reserved.