Figure 1.

Phylogenetic tree highlighting the position of R. thermophilum relative to the type strains of the type species of the other genera within the family Rhodobacteraceae. The tree was inferred from 1,330 aligned characters [6,7] of the 16S rRNA gene sequence under the maximum likelihood (ML) criterion [8]. Rooting was done initially using the midpoint method [9] 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 adjacent to the branches are support values from 650 ML bootstrap replicates [10] (left) and from 1,000 maximum-parsimony bootstrap replicates [11] (right) if larger than 60%. Lineages with type strain genome sequencing projects registered in GOLD [12] are labeled with one asterisk, those also listed as ‘Complete and Published’ with two asterisks [13].