Partial purification and characterization of carotenoid pigment from Haloarcula sp. IRU-I, an extremely halophilic archaeon isolated from Uromia salt lake

An extremely halophilic archaeon، Haloarcula sp. IRU1 which isolated from Uromia lake can produce carotenoid pigments. In this study، we assayed several methods for pigment extraction by using different solvents، ultimately، the cell breakage by employing relatively soft glass powder and acetone: hexane as solvents was selected as the best method. Then، the pigments were separated by Thin Layer Chromatography. In order to pigment separating، we examined several solvents with different percentages and the best separating was performed with acetone: petroleum ether (35:65; v/v). There were appeared six bands on TLC plate and the first one with the least RF was the most high intensity band. A few carotenoid standards were used for primary identification of pigments. The highest intensity band on TLC plate was determined as the main pigment component in this archaeon and was scraped off from TLC for identification. For pigment analyzing، UV-Visible، FT-IR، Mass Spectrometry and NMR spectrums of this band were taken and compared with present references. These results suggested the main pigment of this archaeon is bacterioruberin which is sterified with acetate group.