STRAIN SELECTION FOR BETA-CAROTENE PRODUCTION BY DUNALIELLA

Four strains of Dunaliella were grown at 25-degrees-C and pH 8 +/- 0.5 , with continous illumination at 200 W/m2. Their maximum specific grow th rates ranged from 0.093 day-1 to 0.234 day-1, nitrate yields from 3 .0 to 7.8 g cells/g NaNO3 and lipid contents from 3% to 6% of the dry wt, with carotenes 50 to 80% of the lipids. Of the carotenes, beta-car otene made up 7 to 19%; all-trans-beta-carotene 32 to 52% and 9-cis-be ta-carotene 29 to 55%. There are, therefore, considerable intra-specif ic differences between strains of Dunaliella.