Abstract
Recently, we isolated the purple photosynthetic bacterium, Rhodopseudomonas sp. Rits which possessed BChl a intermediates with non/di/tetrahydrogeranylgeranyl groups as well as phytyl group at the C-17 propionate [1]. In carotenoid biosynthesis, this bacterium mainly accumulated some intermediates of spirilloxanthin including rhodopin and 3,4-didehydrorhodopin. We observed that these intermediary pigments located in peripheral antennas as well as RC-LH1 core complex [2]. Although we have demonstrated that the composition of these pigments was dependent on irradiated light intensity, the effect of incubation period on the pigment compositions has not been analyzed yet. In this study, we measured the quantitative changes of intermediates of BChl a and carotenoids in the Rits strain during cultivation. We will discuss about the relationship between pigment compositions and the types of antenna proteins in this bacterium.
[1] T. Mizoguchi et al. (2006) FEBS lett. 580: 6644-6648.
[2] J. Harada et al. (2007) Photosynth. Res. in press.
