FIG 1.

Phylogenetic tree of the major lineages in the class Thermoplasmata, illustrating the relationship among the mostly uncultivated members of the order Methanomassiliicoccales and to other lineages of the Euryarchaeota. Methanogenic lineages are shaded in gray. Strains with published genomes or draft genomes are in bold. The original tree is based on an unambiguous alignment of more than 300 16S rRNA genes (>1,250 nucleotide positions) and was reconstructed using a maximum-likelihood algorithm (RAxML). The tree was rooted using representatives of other methanogenic lineages. Nodes not supported by neighbor-joining and maximum-parsimony (MP) analyses are shown as multifurcations; highly supported nodes (100 bootstraps, MP) are marked (solid circles, >95%; open circles, >70%). Scale bar indicates 0.1 substitutions per site.