Enhancing production of lutein by a mixotrophic cultivation system using microalga Scenedesmus obliquus CWL-1

• Published in: Bioresource technology 2019-11, Vol.291, p.121891-121891, Article 121891
• Main Authors: Chen, Wei-Chuan, Hsu, Yin-Che, Chang, Jo-Shu, Ho, Shih-Hsin, Wang, Li-Fen, Wei, Yu-Hong
• Format: Article
• Language: English
• Subjects: batch fermentation; Biomass; calcium nitrate; Fed-batch fermentation; Fermentation; Light; Light-related strategies; Lutein; Lutein - biosynthesis; microalgae; Microalgae - metabolism; Nitrate concentration; photophase; red light; Scenedesmus - metabolism; Scenedesmus obliquus; scotophase
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2019.121891

[Display omitted] •White LEDs enable higher lutein production than that of using monochromatic LEDs.•12L:12D cycle with 4-d blue followed by 4-d red light facilitates lutein production.•The nitrate pulse feeding could promote lutein biosynthesis in the microalga.•The obtained lutein productivity (5.0 mg/L/d) is higher than most related studies. This work studies a series of strategies in the production of lutein by Scenedesmus obliquus CWL-1 under mixotrophic cultivation. Our experimental results revealed that the optimal conditions associated with light-related strategies were 12 h light period followed by a 12 h dark period and blue to red light under mixotrophic cultivation. Under such conditions, the biomass, lutein content and lutein productivity were maximized to 9.88 (g/L), 1.78 (mg/g) and 1.43 (mg/L/day), respectively. Moreover, the assimilation of 4.5 g/L of calcium nitrate into S. obliquus CWL-1 increased the maximal biomass (12.73 g/L) and the highest maximal lutein productivity (3.06 mg/L/day), while the assimilation of 1.5 g/L of calcium nitrate yielded the highest maximal lutein content of 2.45 mg/g. The highest maximal lutein productivity of 4.96 (mg/L/day) was obtained when fed-batch fermentation was conducted, and this value was approximately 11-folds that obtained using the batch system.