Hairy roots of red beet ( Beta vulgaris L.) were cultivated in different types of airlift bioreactors ( cone, balloon, bulb, drum and column bioreactors of 5 l capacity and containing 3 l of half strength Murashige & Skoog medium). The cone type of airlift bioreactor gave the highest biomass of hairy roots and betacyanin accumulation. Betacyanin accumulation was 27 mg g(-1) dry wt in cultures aerated at 0.3 vvm. Light irradiation of 20 mumol m(-2) s(-1) promoted hairy root growth but optimum betacyanin ( 34 mg g(-1) dry wt) accumulation was with the cultures grown under 60 mumol m(-2) s(-1).