TABLE 2.

Distribution of hydrothermal vent and deep-sea nifH clones among phylogenetic groupsa

Phylogenetic groupPhylogenetic affiliationNo. of clones in each phylogenetic groupTotal no. of clones
Marker 33 1999 (E)cMarker 33 2000 (A)Puffer 2000 (C)Deep-seawater (B)
Cluster I
E27bα-Proteobacteria11
E10γ-Proteobacteria11
C60, C73, E58γ-Proteobacteria123
Total325
Cluster IIIAnaerobic bacteria
A19, C22, E5, C47, C3671614
C65, C9, E85510
E44, E6333
E1244
A4411
C1911
Total1921233
Cluster IIArchaea and anfH
B28, C70, A34, C59, B25, B20, B7,     B49, B47, B3311691945
A12, E7189
E59, A16, A111438
A2415
Total33292367
Cluster IVDivergent Archaea
A26123
A844
A2111
C8311
C6133
A371113
Total28515
  • a Phylogenetic groups based on ≥92% amino acid similarity.

  • b Representative clone(s) from each phylogenetic group was used to construct phylogenetic trees.

  • c Letter designations for each clone library are used as prefixes in clone names.