Effect of Differences in Type and Concentration of Nitrogen Sources (NaNO3 and Urea) on Spirulina platensis Biomass Production

Abstract

The goal of this study was to investigate the effect of the concentration and the type of nitrogen sources in the cultivation medium on the production of biomass and biochemical content (carbohydrates, proteins, fats) in the Spirulina platensis biomass. Types of nitrogen sources included NaNO₃ and urea, where the concentrations were varied from 0.5 to 3.5 g/L. The results showed that the use of urea tended to produce more S. platensis biomass than the use of NaNO₃. The best concentrations that produced the highest biomass were NaNO₃ 2.5 g/L (biomass 0.6745 g/L) and urea 0.5 g/L (biomass 0.7158 g/L). The use of urea also tended to produce a higher specific growth rate and a shorter doubling time than the use of NaNO₃. The high concentration of nitrogen sources caused the pH of the medium to increase more rapidly due to the accumulation of ammonium in the medium. Using NaNO₃ can produce biomass with a higher protein content (28.34-36.98%) than using urea (25.86-33.52%).