Two-stage Light Wavelengths and Intensities for Enhancement of Astaxanthin Production by Microalga Haematococcus sp. and Application in Phytoremediation of Industrial Effluent

摘要

Various LED light wavelengths and intensities were manipulated to enhance growth and astaxanthin production by microalga Haematococcus sp. Among the strategy tested, two-stage strategy using red LED for first 5 days before switching to blue LED for more 5 days at constant light intensity of 3,000 lux gave the highest astaxanthin production. Under this condition, the microalgal biomass and astaxanthin production obtained were 1,330 mg/L and 2.04 mg/g biomass, respectively. This strategy was applied in phytoremediation of effluent from aerobic pond of seafood processing plant. The COD, nitrogen and phosphorus removal were > 50%, > 93% and > 97%, respectively. Interestingly, the lipid content in Haematococcus sp. biomass was as high as 30.74%. The extracted lipids are mainly composed of C16-C18 (> 96%) and their biodiesel properties were in accordance with the international standards. These results indicated the potential use of two-stage light wavelengths for enhancing of astaxanthin production and phytoremediation of industrial effluent as well as production of lipids as biodiesel feedstocks.