Maximum likelihood phylogeny of the recovered protein sequences from reconstructed Chlorobia-affiliated MAGs/SAGs (highlighted in green) together with the reference protein sequences recovered from GenBank, with the exception of hydrogenases, for which sequences were collected from HydDB (highlighted in gray). Panels A to D show the phylogeny of the following protein sequences: (A) dissimilatory sulfite reductase (DsrA; n = 551), (B) thiosulfohydrolase (SoxB; n = 294), (C) group 1d [NiFe]-hydrogenase (HyaB; n = 579), and (D) putative iron-oxidizing cytochrome (Cyc2; n = 306).