Phylogenetic tree highlighting the position of T. aggregans relative to the other type strains of the other genera within the family Desulfurococcaceae. The tree was inferred from 1,307 aligned characters [8,9] of the 16S rRNA gene sequence under the maximum likelihood criterion [10] and rooted in accordance with the current taxonomy. The branches are scaled in terms of the expected number of substitutions per site. Numbers above branches are support values from 200 bootstrap replicates [11] if larger than 60%. Lineages with type strain genome sequencing projects registered in GOLD [12] are shown in blue, published genomes in bold.

Transmission electron micrographs of cells of T. aggregans strain M11TL^T. A: cells were shadowed with platinum; B: cells were freeze-etched. Scale bars, 1 µm

Graphical circular map of the genome. From outside to the center: Genes on forward strand (color by COG categories), Genes on reverse strand (color by COG categories), RNA genes (tRNAs green, rRNAs red, other RNAs black), GC content, GC skew.

Organization of genes encoding putative membrane-bound multiprotein complexes in T. aggregans and related members of Desulfurococcaceae. Operons of reference genes with asserted function are shown in the first line of each group. Genes with an assumed homologous function are labeled in the same color. Genes encoding subunits of putative multimeric cation-proton antiporters are shown in shades of green; genes with similarity to subunits of [NiFe] hydrogenases/NADH-quinone oxidoreductases are shown in red colors; genes representing the large and small subunit of supposed formate dehydrogenases are displayed in dark and light blue, respectively; genes labeled in yellow are homologous to genes encoding the alpha-subunit of Pyrococcus furiosus sulfide dehydrogenase (sudA); and genes representing hypothetical proteins of unknown function are shown in white. A) MBH-related energy-coupling hydrogenases. B) MBX-related ferredoxin-NADPH oxidoreductases. C) MBX-related ferredoxin-NADPH oxidoreductases. The reference operon of Thermococcus litoralis has been retrieved by cloning a fragment of genomic DNA, so that the arrangement of genes following mnhF could not be determined.