Summary of the main trends at protein level observed for the environmental adaptation of Exiguobacterium. (A–C) Percentage difference between the average amino acid frequency of a given clade relative to the reference clade. (A) Halophilic signature obtained by comparison of Clade IIa to Clade Ia. (B) Psychrophilic signature obtained by comparison of Clade Ib to Clade Ia. (C) Thermophilic signature obtained by comparison of Clade IIb to Clade IIa. P-values were obtained from the Kolmogorov–Smirnov test of the amino acid distribution in the different clades. (D) Amino acid percentage differences between clades when restricted to different protein regions and secondary structures. The three columns correspond to psychrophilic adaptation (Clades Ib vs. Ia), halophilic adaptation (Clades IIa vs. Ia), and thermophilic adaptation (Clades IIb vs. IIa). Arrows ↓↓ and ↓ correspond to a percentage decrease of more than −5% and between −1% and −5%, respectively. Arrows ↑↑ and ↑ correspond to a percentage increase bigger than 5% and between 1% and 5%; − indicates no significant change.