Astaxanthin (3, 3' - dihydroxy-β, β carotene - 4, 4 '- Dione), an orange-red pigment with a high antioxidant activity and antibacterial activity. Yeasts in the genus Rhodotorula, Rhodosporidium, Sporidiobolus, Sporobolomyces are known as potential natural sources for the production of carotenoids in general and for astaxanthin production in particular.