Archaeal diversity associated with in situ samplers deployed on hydrothermal vents on the East Pacific Rise (13°N)

Abstract

To evaluate possible compositional changes in archaeal communities at a deep-sea hydrothermal vent field scale, we examined five different samples obtained after deploying in situ collectors for different times on three spatially separated venting sulphide structures on the East Pacific Rise (13 degrees N). Direct cell counts and whole-cell hybridizations with fluorescently labelled 16S rRNA-based oligonucleotide probes revealed that the relative abundance of archaeal populations represented from 14 to 33% of the prokaryotic community. 16S rDNA sequence analysis of the archaeal clone libraries indicated that a large percentage of clones were closely related to known archaeal isolates recovered from similar habitats. Among the 24 different phylotypes identified, Thermococcales-related sequences were dominant in all the libraries that also included representative genera of orders Methanopyrales, Methanococcales, Archaeoglobales and Desulfurococcales. The presence of most of these phylogenetic groups was confirmed in enrichment cultures performed at temperatures from 60 to 90 degrees C. Additional sequences with no known cultivated relatives grouped with the Marine group I Crenarchaeota, Korarchaeota and Deep-sea Hydrothermal Vent Euryarchaeota (DHVE) within which a novel lineage was identified. Furthermore, the archaeal community composition was distinct from vent to vent within the same vent field and varied within short time scales. This study provides new insights into microbial diversity and distribution at deep-sea hydrothermal vents.

Biogeography and ecology of the rare and abundant microbial lineages in deep-sea hydrothermal vents

“…Because previous work has 373 indicated that uncultured crenarchaea dominate the interior of sulfide structures (Schrenk 374 et al 2003), we conducted global sequence comparisons of the Hulk high-temperature 375 v4-v6 region against a database of uncultured crenarchaea identified from sulfide clone 376 libraries. Two sequences were found that matched previously identified crenarchaea in 377 sulfides at 99-100% identity: a Desulfurococcales lineage from a white smoker spire on 378 the East Pacific Rise (Kormas et al 2006), and a Pyrodictium lineage identified in an in-379 situ growth chamber deployed within a sulfide structure (Nercessian et al 2003). 380 381 Discussion 382…”

Deep-sea hydrothermal vent bacteria related to human pathogenic Vibrio species

“…Samples were collected from two sites on the East Pacific Rise, 9°50′N, 104°17′W by Deep Submergence Vehicle Alvin, and 13°N (12°49′N, 103°56′W) at a depth of 2,500 m by Deep Submergence Vehicle Nautile. Further description of sampling procedures and isolation sites has been described elsewhere (68). Samples were inoculated into heterotrophic, anaerobic seawater-based media immediately after sample retrieval onboard the mother ship.…”

The origin and emergence of life under impact bombardment

“…The metabolic characteristics of these communities might be analogous to those that inhabit deep-ocean hydrothermal systems today (e.g. Nercessian et al 2003;Alain et al 2004). As there is no fresh crater available for study, the true nature of the hydrothermal microbial ecosystems that inhabited early Archaean craters must be subject to some conjecture, but if the earliest life forms were hyperthermophilic, perhaps owing to an evolutionary bottleneck, then impacts would not only have caused this bottleneck, but also would have generated hot conditions that favoured colonization by the microorganisms that survived the previous impacts.…”