KETOCAROTENOIDS IN HALOBACTERIA - 3-HYDROXY-ECHINENONE AND TRANS-ASTAXANTHIN

HPLC testing of the carotenoid content of the halobacteria Halobacteri um salinarium, Haloarcula hispanica and Haloferax mediterranei showed that all contained high amounts of ketocarotenoids, Halobacterium sali narium produced 2400 mu g of total carotenoids per gram of dried bacte ria, including 265 mu g of trans-astaxtanthin (11%), and 588 mu g of 3 -hydroxy-echinenone (24%). The biotechnological properties of Halobact erium salinarium as a natural pigment source are also presented. The r esults are compared with those from the yeast Phaffia rhodozyma,ma cur rently used in the industry as a source of trans-astaxanthin.