Fig. 2

a Concatenated ribosomal protein phylogeny of the Chloroflexota, focusing on order SBR1031 (Aggregatilineales). Organisms encoding phototrophy with a Type 2 reaction center highlighted in green (including TC_22, which did not recover reaction center genes but may be a phototroph, as discussed in the text). Genomes first described here noted with pink circles. As species names are not available for MAGs of uncultured organisms, strains are labelled with MAG IDs (this study) or NCBI WGS database IDs (others) followed by taxonomy as derived from GTDB-Tk. Clades not the focus of this study have been collapsed and labeled with GTDB-Tk taxonomy. b Tanglegram showing phylogenetic (in)congruence between concatenated ribosomal proteins (left) reflecting organismal relationships with PufM (right) as a marker of the horizontal gene transfer of phototrophy proteins. Dotted lines show topological congruence within some lineages of Chloroflexia (in black) and incongruence between Roseiflexus, Roseilinea, and phototrophic members of SBR1031 (in red). This is indicative of horizontal gene transfer of phototrophy proteins from the Roseiflexus lineage to Roseilinea and SBR1031