Figure 4.

The 15 ribosomal protein concatenated phylogeny places the 14 archaeal operational taxonomic units as novel organisms compared with previously sequenced genomes in 0.1-μm samples. RAxML phylogenetic tree with 100 bootstrap resamplings rooted at the split between archaea and bacteria. Numbers in parentheses indicate number of sequences included in the analysis that are not show. Fourteen distinct archaeal ribosomal blocks were identified in all of the 0.1-μm data sets, all of which are novel at least at the species level. Organism colors are consistent with Figure 2. Six are Nanohaloarchaea (basal archaeal group on the tree), all shown in purple and a gradient of blue. The organism most closely related to Candidatus Nanosalina sp. J07AB43 is the most abundant organism on the 0.1-μm filters (in teal on this tree and marked with an asterisk).