FIG. 2.

Phylogenetic tree based on 16S and 18S rRNA sequences. The tree was constructed based on complete 16S and 18S rRNA sequences using the ARB software package. The thick lines represent the (hyper)thermophilic lineages, and the thin lines represent the mesophilic lineages. PFK activity or related sequences identified in the different species on the genomic and/or functional level are marked as follows: ∗, ADP-PFK; #, ATP-PFK; ^, PP_i-PFK; ○, ADP-PFK activity present; , ADP-dependent (sugar) kinase homolog present; ●, both ADP-PFK activity and homologous gene identified.