[Polyphosphate biosynthesis in Rhodospirillum rubrum chromatophores]

The chromatophores of Rhodospirillum rubrum were found to synthesize in the light not only ATP and pyrophosphate but also high molecular weight polyphosphates. Biosynthesis of all studied compounds was inhibited by antimycin A, an inhibitor of the electron-transport photosynthetic chain. Synthesis of high molecular weight polyphosphates is stimulated, while that of pyrophosphate is inhibited, in the conditions providing intensive synthesis of ATP (in the presence of ADP and in the absence of oligomycin). The results obtained suggest that biosynthesis of high molecular weight polyphosphates is related to photosynthetic phosphorylation, via ATP but not pyrophosphate.