Abstract
Recently, we isolated the purple photosynthetic bacterium, Rhodopseudomonas sp. strain Rits, which is phylogenetically close to Rhodopseudomonas palustris. These bacteria have similar photosynthetic properties that both bacteria synthesize light-harvesting(LH) 4, showing different absorption spectrum from LH2, under low-light conditions, in addition to producing LH1 and 2 under high or normal light conditions. The compositional analysis of chlorophyll pigments from the strain Rits indicated that this bacterium accumulated a significant amount of Bacteriochlorophyll (BChl) a intermediates possessing non/di/tetrahydrogeranylgeranyl groups at the C-17 propionate. However, the localization and function of these intermediates in this organism were still unrevealed. In this study, we analyzed the compositions of BChl a and carotenoids from intact cells of Rits that were grown by irradiation of different light intensity, and decided the localization of these pigments in this bacterium by investigating pigment compositions of RC-LH1, LH2 and LH4 complexes purified from those cells.
