After cultivating blue-green algae Spirulina platensis remains its cultural liquid actually becomes a biotechnological waste. This liquid contains important biologically active substances and might be used as culture medium for other microalgae. An appropriate representative is the green microalgae Dunaliella salina – a valuable source of
β-carotene. The medium D. salina optimization has been carried out. The major cultural factors of influence (salinity, light intensity) on Dunaliella salina
productivity have been determined.
