Figure 1.

Phylogenetic tree highlighting the position of O. profundus relative to the other type strains within the family Thermaceae. The tree was inferred from 1,420 aligned characters [6,7] of the 16S rRNA gene sequence under the maximum likelihood criterion [8]. Rooting was initially done using the midpoint method [9] and then checked for its accordance with the current taxonomy (see Table 1) and rooted accordingly. The branches are scaled in terms of the expected number of substitutions per site. Numbers to the right of bifurcations are support values from 1,000 bootstrap replicates [10] if larger than 60%. Lineages with type strain genome sequencing projects that are registered in GOLD [11] but remain unpublished are labeled with one asterisk, published genomes with two asterisks [12–14].