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

Abstract

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 3×3 factorial design (NaNO3 levels: 3, 10 and 20mM; KH2PO4 levels: 20, 50 and 150μM). The algae grown under medium nitrogen concentration (10mM) and high phosphate concentration (150μM) reached the highest biomass (1223.5±152.5mg/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 (3mM) and phosphate concentration (20μM) 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 (10mM) and low phosphate concentration (20μM) had the highest FAME productivity (426.0mg/L±135.0mg/L). Thus, the lower nitrogen concentration (3mM–10mM) and low phosphate concentration (20μM) would be an optimal combination tested to produce the most FAME from S. rubescens-like algae.