FIG 3.

Phylogenetic tree constructed from full-length 16S rRNA gene sequences of cultivated sulfate-reducing bacteria within the Deltaproteobacteria. The tree shows SRB isolates capable of direct electron uptake (EMIC; orange and ★) and hydrogenotrophic SRB that cannot corrode iron by the EMIC mechanism (blue and *). Other SRB (black) were not tested on Fe⁰. All depicted SRB corrode iron via the CMIC mechanism in the presence of suitable electron donors and sulfate. The tree does not include all cultivated SRB. I, Desulfobulbaceae; II, Desulfobacteraceae; III, Desulfovibrionaceae. The tree was calculated based on maximum likelihood with the ARB software package and SILVA database (126, 127). Branching with bootstrap values below 75 is not depicted. The scale bar represents a 10% difference in sequence similarity. “Mic” isolates are from Mori et al. (2010) (47). The figure was adapted from Enning (2012) (61).