Optimizing microalgae cultivation for enhanced lutein production: screening of high-yield strains and cultivation strategy development
摘要
Microalgae are widely recognized as a promising source of lutein. However, the potential of lutein production by different microalgae varies greatly. This study aims to optimize lutein production by screening high-yield microalgae strains and refining cultivation conditions. Four microalgae strains—Selenastraceae sp. B10, Pectinodesmus sp. F13, Parachlorella kessleri HH2, and Chlorella protothecoides CS-41—were evaluated under autotrophic, heterotrophic, and mixotrophic cultivations. The result indicated that biomass concentration and lutein content were higher in P. kessleri HH2 and C. protothecoides CS-41. The modified Basal medium facilitated the specific growth rate of 1.99 day−1 of P. kessleri HH2, and the maximum biomass concentration of 33.3 g L−1 was achieved by fed-batch cultivation, which was four times higher than batch cultivation. Under autotrophic cultivation, P. kessleri HH2 exhibited robust growth with a maximum biomass of 12.05 g L−1 in high-light and narrow-diameter tubes, while the maximum lutein yield of C. protothecoides CS-41 was 27.77% higher than that of P. kessleri HH2. Two-staged cultivation further improved lutein yield of C. protothecoides CS-41 by 179% increase than that of heterotrophic group. Furthermore, compared to red light and blue light, white light was indicated to increase both cell growth and lutein synthesis of C. protothecoides CS-41, with the biomass concentration of 21.20 g L−1, lutein content of 7.67 mg g−1 and lutein yield of 138.15 mg L−1, which were 5.21%, 16.31% and 42.00% higher than those obtained under blue light, respectively. Consequently, this study indicated that C. protothecoides CS-41 was a promising source for lutein production.