Investigation of <Emphasis Type="Italic">Chlorella vulgaris</Emphasis> UTEX 265 Cultivation under Light and Low Temperature Stressed Conditions for Lutein Production in Flasks and the Coiled Tree Photo-Bioreactor (CTPBR)

Lutein has an increasing share in the pharmaceutical and nutraceutical market due to its benefits to eye health. Microalgae may be a potential source for lutein production while the expense limits the commercialization. In this study, a coiled tubular tree photobioreactor (CTPBR) design was investigated for cultivating the cold tolerant microalgae Chlorella vulgaris UTEX 265 under various conditions for lutein production. The influence and interaction of light irradiance strength, lighting cycle, and temperature on microalgae and lutein production efficiency at low temperature range were also studied in flasks via response surface method (RSM). The results demonstrated that 14 h day-light, 120 μmol photons m^?2 s^?1, and 10 °C was the optimal condition for algae growth and lutein production at low temperature experimental ranges. C. vulgaris UTEX 265 showed good potential to produce lutein in cold weather, and the optimum lutein production was contrary to the specific lutein content but corresponds to the trend of optimum growth. Additionally, fast growth (μ = 1.50 day^?1) and good lutein recovery (11.98 mg g^?1 day^?1) in CTPBR were also achieved at the low irradiance stress condition and the low temperature photo-inhibition conditions.