Biomass production and fatty acid profile of a Scenedesmus rubescens-like microalga

This investigation examined the effects of nitrogen-phosphate combined deficiency on the biomass yield, fatty acid methyl esters (FAME) production and composition from Scenedesmus rubescens-like microalga. A 15-day indoor culture was performed as a 3 x 3 factorial design (NaNO3 levels: 3, 10 and 20 mM; KH2PO4 levels: 20, 50 and 150 mu M). The algae grown under medium nitrogen concentration (10 mM) and high phosphate concentration (1501 mu M) reached the highest biomass (1223.5 +/- 152.5 mg/L). Both nitrogen and phosphate had a significant influence on the FAME yield (P < 0.05 and P < 0.0001, respectively). The FAME yield from algae grown under low nitrogen (3 mM) and phosphate concentration (20 mu M) increased throughout the experiment and the highest FAME yield (42.2 +/- 2.5% of AFDW) as well as C16 and C18 content (95.8 +/- 1.6% of AFDW) was achieved under these conditions. Algae grown under medium nitrogen concentration (10 mM) and low phosphate concentration (20 mu M) had the highest FAME productivity (426.0 mg/L +/- 135.0 mg/L). Thus, the lower nitrogen concentration (3 mM-10 mM) and low phosphate concentration (20 mu M) would be an optimal combination tested to produce the most FAME from S. rubescens-like algae. (C) 2011 Elsevier Ltd. All rights reserved.