The aim of this study was to investigate the effects of sodium nitrate (NaNO3) limitation on cyanobacterium Synechocystis PCC 6803 growth in order to increase its lipid content. The results revealed that the nitrate limitation conditions increase the volumetric biomass productivity, reaching the maximum content at 0.75 g/L NaNO3 (0.043 g/L.day). The maximum chlorophyll a and b concentrations were 6.42 mu g/mL (0.75 mu g/L NaNO3) and 0.63 mu g/mL (1.25 NaNO3), respectively for Synechocystis PCC 6803, cultured in week 9. Also, Synechocystis PCC 6803 exhibited a decrease of protein content and an increase of lipid content with the decrease of NaNO3 concentration. The obtained results suggested that a concentration of 0.75 mu g/L NaNO3 in the Synechocystis PCC 680 growth medium resulted in the highest lipid content (21.3%), making it a potential feedstock for biodiesel production. (C) 2019 Elsevier Ltd. All rights reserved.