Phylogenetic diversity of phototrophic purple non-sulfur bacteria in the Proteobacteria α group

Abstract

The phylogenetic structure of non-sulfur purple bacteria in the Proteobacteria α group was elucidated by the comparative analysis of 16S rRNA sequences from 29 strains of phototrophs and 14 strains of related non-phototrophs. The sequences of 12 strains including 7 isolates were determined in this study. The phototrophs in the α group were found to be extremely diversified and intermingled with non-phototrophs. Rhodopseudomonas species were dispersed into 3 lines of descent and Rhodospirillum species were dispersed into 5 lines. Marine organisms were composed of 4 lineages which were independent of each other and of freshwater lineages. Rhodospirillum fulvum, Rhodospirillum molischianum and the genus Magnetospirillum were found to be monophyletic. © 1993.