The main superiorities using microalgae than marigold flowers to produce lutein are their higher growth rate and lower water demand. The benefit from algae’s high growth rate is their high CO2 fixation rate, with one kg microalgae storing 1.85 kg CO2. Another advantage is that microalgae may be cultivated on nonarable land over all seasons. Then, why haven’t there been any successful commercial lutein products from microalgae?