Properties of ribonucleic acids from photosynthetic and heterotrophic Rhodospirillum rubrum.

Rifampicin causes an initial rapid breakdown of about 30% of the pulse-labeled RNA in both photosynthetic and heterotrophic Rhodospirillum rubrum. An additional degradation of RNA has been observed in the heterotrophic, but not in the photosynthetic cells at a later stage of rifampicin treatment. This secondary RNA degradation is probably caused by breakdown of ribosomal RNA, especially of the 23S species, as shown by polyacrylamide gel electrophoresis analyses. No qualitative difference between the pulse-labeled RNA species in photosynthetic and heterotrophic cells can be detected by the DNA-RNA hybridization competition technique.