ABSTRACT
Carotenoids play an important role in regulating the hydrogen production of hydrogen-producing Rhodobacter sp. The carotenoids of hydrogen-producing Rhodobacter sp. grown in acetate medium were extracted by using acetone-methanol (7∶2,V/V) solvent and were separated by using thin-layer chromatography on silica-gel plate. The qualitative and quantitative of the carotenoids were analyzed by spectrometry. The results showed that the carotenoids were completely extracted three times with acetone-methanol (7∶2,V/V) in two hours. The ultrasonication had little effect on yield of carotenoids. The yield of carotenoids was 2.81mg/g wet cell. There were 4 spots on the silica-gel plate in the order of yellow, red, light red and light yellow. Yellow spot and red spot were the dominant composition of carotenoid in Rhodobacter sp. The spectrometry data showed that the yellow and red component might be the spheroidene and spirilloanthin respectively.