Microalgae produce a wide range of compounds including pigments, protein, starch, and lipids, which have been extensively used for various applications. In the current scenario, microalgal lipids are considered as a promising source for the production of next generation bioenergy and huge productivity is needed to meet the demand. Thus, to increase the production of biomass and lipid content, physical conditions play an important role and necessary to be optimized. The present study made such an attempt to optimize physical factors for the growth and production of lipid from Nannochloropsis gaditana. The study aimed to determine the effect of physical parameters such as pH, temperature, light intensity and salinity. The results showed that the maximum growth rate of the Nannochloropsis gaditana was noticed in 25 ppt salinity, pH 8, temperature 25̊ C and 2000 lux of light intensity. The highest lipid content of the Nannochloropsis gaditana was noticed in 30 ppt of salinity, pH 8, temperature 30˚ C with 2000 lux light intensity. After optimization, above 40 % of lipid yield was obtained and it can be effectively utilized in bioenergy production.
Key words: Microalgae; Nannochloropsis gaditana; Optimization; Physical factors; Growth; Lipid production