TABLE 2

Numbers of cells detected by FISH with methanotroph-specific probes in muddy fluids sampled from the seeps

SeepNo. of cells detected with the following oligonucleotide probe(s) (g−1 of dry mud):No. of DAPI-stained cells (108 g−1 of dry mud)% methanotrophs of DAPI-stained cells/% methanotrophs of EUB338-mix-hybridized cells
M84/M705a (107)M450b (105)EUB338-mix (108)
14.29 ± 0.102.84 ± 1.922.1 ± 1.43.98 ± 0.5710.9/20.2
22.74 ± 0.1811.70 ± 11.11.4 ± 3.42.33 ± 0.1812.2/20.5
  • a The target specificity of probe M84 includes members of the genera Methylobacter, Methylomonas, Methylococcus, Methylomicrobium, Methylosarcina, and Crenothrix polyspora. Probe M705 targets Methylobacter, Methylomonas, Methylococcus, Methylosarcina, Methylosphaera, and Methylovulum. These probes do not target members of the family Methylothermaceae (i.e., thermophilic and halophilic methanotrophs of the genera Methylothermus, Methylohalobius, and Methylomarinovum).

  • b Probe M450 targets all currently described members of the genera Methylosinus and Methylocystis.