Effect of temperature on lipid accumulation in three green microalgae species

Abstract

The objective of this work was to analyze the growth of Scenedesmus acutus , Nannochloropsis oculata and Chlorella vulgaris at different temperatures (25, 30 and 38°C) in order to identify changes in lipid content, accumulation of neutral lipids and fatty acids profile. According to the results obtained, the temperature of 30°C does not affect the growth of the microalgae S. acutus , N. oculata and C. vulgaris ; however, there is a greater amount of total lipids in S. acutus at 38°C, while for N. oculata and C. vulgaris , temperature variation does not affect the accumulation of total lipids. From the data obtained from the fatty acid profile, we observed a greater accumulation of palmitic acid followed by oleic acid. According to the cetane number, any temperature condition of any evaluated microalgae culture can be used for biodiesel production. The results suggest that a change in temperature during the growth of microalgae could be applied to enhance lipid production and to obtain fatty acids suitable for biodiesel production. The analysis was made in duplicate and the mean and standard deviation were reported. An analysis of variance (ANOVA, p < 0.05), using Fisher's test, was made to detect differences between the fatty acids obtained by the different strains.