Time course profiles of biomass concentration, nitrate concentration, and lipid content during growth of Chlamydomonas sp. JSC4 before and after gradient operation with (a) 0.5%, (b) 1.0%, or (c) 1.5% sea salt. Error bars indicate standard deviation of three replicated experiments. (Light intensity = 200 μmol m-2 s-1; CO2 aeration = 2.0%; CO2 flow rate = 0.05 vvm). DCW, dry cell weight.