Effects of light-emitting diodes (LEDs) on the accumulation of lipid content using a two-phase culture process with three microalgae.

Conditions of light-emitting diode (LED) wavelength, light intensity, nitrate concentration, and time of exposure to green LED light stress in a two-phase culture were optimized for lipid production with three species of microalgae. Among the three microalgae, Nannochloropsis oculata showed the highest specific growth rate ( μ max ) of 0.037 h −1 and the lowest saturation constant ( K s ) of 1.32 mg/L. The highest lipid contents of the three microalgae in the second phase under green LED light stress were 52.0% (w/w) for Nannochloropsis salina at 2 days, 53.0% (w/w) for Nannochloropsis oceanica at 2 days, and 56.0% for N. oculata at 2 days. Fatty acid analysis of the microalgae showed that 85–87% (w/w) of total fatty acids from N. salina , N. oceanica , and N. oculata consisted of palmitic acid (C16:0) and oleic acid (C18:1). [ABSTRACT FROM AUTHOR]