Phylogenetic tree highlighting the position of R. rubrum S1T relative to the other type strains within the family Rhodospirillaceae. The 16S rRNA accessions were selected from the most recent release of the All-Species-Living-Tree-Project  as far as possible. The tree was inferred from 1,361 aligned characters [5,6] of the 16S rRNA gene sequence under the maximum likelihood criterion . Rooting was done initially using the midpoint method  and then checked for its agreement with the current classification (Table 1). The branches are scaled in terms of the expected number of substitutions per site. Numbers to the right of bifurcations are support values from 550 bootstrap replicates  if larger than 60%. Lineages with type strain genome sequencing projects registered in GOLD  are labeled with one asterisk, those also listed as ‘Complete and Published’ with two asterisks.