NEW MODE OF DUNALIELLA BIOTECHNOLOGY - 2-PHASE GROWTH FOR BETA-CAROTENE PRODUCTION

Attempts to adapt the laboratory experience of bi-phasic growth and carotenogenesis in Dunaliella to large-scale conditions were highly successful. Algae were initially cultivated in stage one for optimizing biomass production of cells containing a low beta-carotene to chlorophyll ratio. The culture was then transferred to stage two, diluted to about one third and induced for carotenogenesis. The bi-phase cultivation increased beta-carotene productivity to 450 mg m-2 d-1 in stage one and to 300 mg m-2 d-1 in stage two, compared to the relatively low productivity of below 200 mg beta- carotene m-2 d-1, in the conventional one phase type of cultivation. The results indicate that a selected algal product can be promoted specifically by growth manipulation of the alga and its environment.