Production and rapid extraction of lutein and the other lipid-soluble pigments from Chlorella protothecoides grown under heterotrophic and mixotrophic conditions

Abstract

Chlorella protothecoides was successfully cultivated under mixotrophic and heterotrophic conditions. The maximum biomass concentrations of the alga grown at an initial glucose concentration of 40 g/l in the light and in the dark were 22.4 g/l and 17.2 g/l dry cells, respectively. A mechanical method using a new model of dispersing instrument, UltaTurrax T25, was developed for the extraction of the pigments from C. protothecoides cells. Lutein and the other lipid-soluble pigments were separated well by an HPLC system. The contents of lutein, α-carotene, β-carotene, chlorophyll a and chlorophyll b extracted by the mechanical method from the heterotrophic and mixotrophic C. protothecoides cells were 4.43, 0.32, 0.94, 43.76, 9.14 and 6.48, 0.55, 0.66, 56.75, 9.78 mg/g dry cells, respectively. The recoveries of the five pigments through the mechanical extraction were 97.5-99.6%. In contrast, no chlorophylls a and b were obtained through the alkali extraction.