Lipid content and biomass production could be
enhanced by increasing light intensity[35]. Light intensity could
affect the activity of key enzymes in the synthesis process of fatty
acid by changing pH, Mg
2+
and NADPH in cell stroma[12]. The
higher light intensity might have contributed to the positive accumulation of lipid by improving the activity of key enzymes in this
study, which led to higher lipid content. Also, due to high dry biomass concentration at the three illumination densities of 6000,
8000 and 10,000 lux, the ultimate lipid productivity was much
more than that at 2000 and 4000 lux