An optical fibre photobioreactor for enhanced production of the marine unicellular alga Isochrysis aff. galbana T-Iso (UTEX LB 2307) rich in docosahexaenoic acid

We have screened six species of marine microalga for their ability to produce the important dietary lipid docosahexaenoic acid (DHA). Isochrysis aff. galbana T-Iso (UTEX LB 2307), which produced DHA in the highest quantities (5.4 mg-g^-1), was grown in a new type of closed photobioreactor in which efficient light distribution was achieved using light-diffusing optical fibres. The optimal temperature and light intensity for DHA production were determined and a maximal DHA production of 4.3 mg-l was achieved, twofold greater than that obtained using conventional culture methods. In addition, the DHA content could be enhanced by low temperature or dark incubation of the culture after growth.