The differentiation of the photosynthetic apparatus and the intracytoplasmic membrane in cells of Rhodopseudomonas capsulata upon variation of light intensity.

In cells of Rhodopseudomonas capsulata, grown at growth limiting light intensity (7 W x m-2), the cellular bacteriochlorophyll (Bchl) content increased 13-fold, the Bchl concentration of membranes 3.4 fold, the concentration of reaction centers in membranes 1.6-fold, the size of the photosynthetic unit twofold, the concentration of carotenoids in membranes 2.4 fold and the number of intracytoplasmic membrane vesicles, bearing the photosynthetic apparatus, 6..3 fold in comparison with cells grown at 2000 W x m-2 light intensity. Thus, the variation of incident caused mainly a variation of the amount of intracytoplasmic membrane vesicles per cell, but also a variation of the size and concentration of photosynthetic units in the membrane system.