Fig. 2

Phylogenetic tree of bacterial operational taxonomic unit (OTU) sequences with a relative abundance > 0.5% of the total 16S rRNA gene sequences in at least one of the representative ultraheavy, heavy, and light fractions. The relative abundances are shown as heat maps to the right of the phylogenetic tree. The figure was produced from the Interactive Tree Of Life (iTOL, http://itol.embl.de/). 13C and 12C represent substrate NaH13CO3 and NaH12CO3, 15N and 14N represent substrate 15NH4Cl and 14NH4Cl, respectively. WV, white vent; YV, yellow vent; IS, in situ; C, class; O, order; F, family; G, genus