Figure 1.

Phylogenetic tree highlighting the position of N. salsuginis strain E9I37-1^T relative to the other type strains within the family Nautiliaceae. The tree was inferred from 1,356 aligned characters [6,7] of the 16S rRNA gene sequence under the maximum likelihood criterion [8] and rooted in accordance with the current taxonomy. The branches are scaled in terms of the expected number of substitutions per site. Numbers to the right of bifurcations are support values from 200 bootstrap replicates [9] if larger than 60%. Lineages with type strain genome sequencing projects registered in GOLD [10] are labeled with an asterisk when unpublished, and with two asterisks when published [11]. The closest BLAST hit to N. salsuginis (see above) does not belong to Nautiliaceae, and this family does not appear as monophyletic in the last version of the 16S rRNA phylogeny from the All-Species-Living-Tree Project [12]. The species selection for Figure 1 was based on the current taxonomic classification (Table 1). However, an analysis including the type strains of Nautiliaceae and its neighboring families Campylobacteraceae, Helicobacteraceae and Hydrogenimonaceae (data not shown) did not provide evidence for the non-monophyly for any of these families.