Phylogenetic neighbor-joining tree based on 16S rRNA genes extracted from 145 genomes (24 Negativicutes and 121 prokaryotic genomes representing 26 phyla). Bootstrap values of 50 and higher are indicated. With the exception of the Negativicutes, branches where all organisms belong to the same phyla are collapsed and named by the phyla they represent. The green shading indicates the position of Firmicutes. The collapsed branch of the Bacilli, marked (1), contains Turicibacter sanguinis, a Firmicutes member of the Erysipelotrichales as well as Bacilli members. An uncollapsed tree is included in the supplementary material.