The production of pigments by Haloferax mediterranei ATCC 33500 with two-stage cultivation in response to nutritive factors in culture media was studied. Sodium chloride and magnesium sulfate in the second-stage media showed a marked effect upon the production of pigments, and sodium acetate could enhance the production. As the cells were harvested at mid-log phase of growth in first-stage cultivation and transferred to the defined media containing 5% sodium chloride, 0.1% sodium acetate and 8% magnesium sulfate at 37 degrees C, 120 rpm for further 24 h of cultivation, H. mediterranei exhibited to be an efficient producer of pigments. The yield of pigments could reach up to 0.604 A(494 nm) mL(-1) broth. TLC analysis and the UV-Vis spectra of individual spots thereof revealed that H. mediterranei produced three red pigments of C-50 carotenoid, namely bisanhydrobacterioruberin, monoanhydrobacterioruberin and bacterioruberin, as well as a C-45 carotenoid, 2-isopenteny1-3,4-dehydrorhodopin. (C) 2010 Elsevier Ltd. All rights reserved.