The micro-alga Dunaliella tertiolecta ATCC 30929 could be grown under highly saline conditions (6% of NaCl aqueous solution) without the need for sterilization of the bio-reactor or the culture medium which would be greatly advantageous in a scale up of the culture system. Using CO2 as a carbon source, the microalgae growth reached 1.0 g/l under non-sterilized conditions after one week, The effect of contamination by other micro-organisms on the growth was negligible. The micro-alga contained 10% glycerol, and the yield of its conversion to oil by thermo-chemical liquefaction was 36%, indicating the possibility of effective oil production by CO2 fixation using such a micro-alga.