Optimization of Culture Medium to Increase The Biomass Production of Scenedesmus obliquus; the Impact of Carbon Source

This study aimed to investigate the effect of adding an exogenous carbon source on the growth of Scenedesmus obliquus. For this purpose, the impact of three carbon sources, including sodium acetate (two concentrations of 0.01 and 0.02g/l), sodium carbonate (two concentrations of 0.01 and 0.02 g/l), and aeration to supply carbon dioxide on the growth and production of S. obliquus biomass cultured on BBM medium were investigated. Based on the results, all three carbon treatments significantly increased biomass production and microalgae growth compared to the control group (P <0.01). Among the carbon sources studied, the concentration of 0.02g/l sodium acetate had the most significant effect on microalgae growth. Therefore, this treatment uses for the heterotrophic culture of S. obliquus. Aeration treatment also increased the biomass concentration of the microalgae compared to control (P<0.01). This assay showed that S. obliquus was capable of heterotrophic growth using acetate as a carbon source. The results also showed that carbon treatments significantly increased the content of photosynthetic pigments in microalgae (P <0.01). Since pH may affect algal growth, an examination of the pH trend showed that acetate and carbonate treatments significantly increased the pH of the culture medium at the end of the experiment. In contrast, aeration treatment did not affect pH change compared to the control group.