Fig. 1.

(a) Geographical locations of the Halorubrum isolates, and (b) Halorubrum phylogeny reconstructed by PhyloPhlAn 3.0 based on the 400 most universal markers using maximum likelihood algorithm. The central clade highlighted in blue starts with Halorubrum sp. DL18, which was isolated from Antarctica’s Deep Lake, and ends with Halorubrum sp. LN27, which was isolated from a deep salt column (350 m); this clade represents the polar and deep-earth group (in blue). The bar labelled ‘0.2’ indicates accumulated changes per amino acid. Dots at nodes indicate bootstrap proportions for the tree. The phylogenomic tree was sorted by increasing node order using FigTree, as described in the ‘Materials and methods’ section