Lutein production with wild-type and mutant strains of Chlorella sorokiniana MB-1 under mixotrophic growth

Lutein is a type of xanthophyll found in the macular region of eye, helps in reducing the risk of age-related macular degeneration (AMD). In this study, lutein production from the wild type Chlorella sorokiniana MB-1 and the mutants generated by random mutagenesis were tested for their lutein productivity. The wild-type strain of C. sorokiniana MB-1 obtained the highest lutein productivity and lutein content of 2.39 mg/L/day and 5.86 mg/g, respectively, when 6.0 g/L sodium acetate was used as the organic carbon source in mixotrophic cultivation. Under the same conditions, mutant strain MB-1-M12 had better lutein production performance than that of the wild-type strain, exhibiting a lutein content and productivity of 7.52 mg/g and 3.63 mg/L/day, respectively. Outdoor cultivation of mutant strain MB-1-M12 obtained a slightly lower lutein content of 6.85 mg/g but a markedly lower productivity of 1.35 mg/L/day when compared to the indoor culture operated under well-controlled conditions with whole-day illumination. The satisfactory lutein production performance from outdoor culture of MB-1-M12 strain demonstrates the potential in commercial production of lutein using the mutant strain.