Evaluation of the simultaneous production of lutein and lipids using a vertical alveolar panel bioreactor for three Chlorella species

The concept of a biorefinery improves the economic efficiency of a biofuel production process from microalgae by recovering high value added compounds. Lutein is a carotenoid currently extracted from petals of Tagetes erecta with an established market in poultry and in human nutritional supplements. For the very first time, an extended study on the lipid and lutein production over three Chlorella species as well as cell disruption methods was performed. Chlorella vulgaris, Chlorella zofingiensis and Chlorella protothecoides were grown in an indoor vertical alveolar panel photobioreactor with continuous illumination, and two cell disruption methods were assessed at a laboratory scale: glass bead vortexing and ball mill grinding. For C. vulgaris, C. zofingiensis and C. protothecoides the intracellular lutein content was measured as: 3.86, 4.38 and 3.59mgg^-1 respectively. Lipid contents vary slightly among microalgae with a value close to 9% w/w. Biomass and lutein productivities were found to be higher for C. vulgaris (0.131gL^-1d^-1, 0.51mgL^-1d^-1) and for C. zofingiensis (0.122gL^-1d^-1, 0.53mgL^-1d^-1) compared to C. protothecoides (0.103gL^-1d^-1, 0.37mgL^-1d^-1).C. vulgaris 1803 and C. zofingiensis B 32 were found to be promising organisms for simultaneous production of lutein and lipids. Although all the microalgae under study belong to the same genus, a species-specific response was observed for each of the cell grinding methods tested.