title: Recovery of crenarchaeotal ribosomal DNA sequences from freshwater-lake sediments.
abstract: We report several novel environmental sequences of archaea from the kingdom Crenarchaeota, recovered from anaerobic freshwater-lake sediments in Michigan. A nested PCR approach with Archaea- and Crenar-chaeota-specific primers was used to amplify partial Small-subunit ribosomal DNAs. Phylogenetic analysis of seven sequences shows that these DNAs represent a monophyletic lineage diverging prior to all recently identified crenarchaeotal phylotypes isolated from temperate environments. Including our lineage, all uncultured crenarchaeotal sequences recovered from moderate or cold environments form a distinct, monophyletic group separate from the "genuine" thermophilic crenarchaeota. Our finding extends the emerging picture that crenarchaeota, thought until recently to be solely extreme thermophiles, have radiated into an unexpectedly large variety of ecologically important, temperate environments.
authors.affiliation: Marine Science Institute, University of California, Santa Barbara 93106, USA. christa@anarchae.lscf.ucsb.edu
authors.forename: C
authors.initials: C
authors.lastname: Schleper
authors.forename: W
authors.initials: W
authors.lastname: Holben
authors.forename: H P
authors.initials: HP
authors.lastname: Klenk
mesh_terms: D001105:Archaea / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics* / Q000302:isolation & purification*; D004275:DNA, Ribosomal / Q000235:genetics / Q000302:isolation & purification; D017753:Ecosystem; D005618:Fresh Water / Q000382:microbiology*; D008824:Michigan; D008969:Molecular Sequence Data; D010802:Phylogeny; D013696:Temperature
chemical_list: D017931:DNA Primers; D004269:DNA, Bacterial; D004275:DNA, Ribosomal