title: Diversity and community structure of archaea in deep subsurface sediments from the tropical Western pacific.
abstract: Archaeal 16S rRNA gene clone libraries using PCR amplicons from eight different layers of the MD06-3051 core were obtained from the tropical Western Pacific sediments. A total of 768 clones were randomly selected, and 264 representative clones were sequenced by restriction fragment length polymorphism. Finally, 719 valid clones and 104 operational taxonomic units were identified after chimera-check and > or =97% similarity analysis. The phylogenetic analysis of 16S rDNA sequences obtained from sediment samples were very diverse and showed stratification with depth. Majority of the members were most closely related to uncultivated groups and physiologically uncharacterized assemblages. All phylotypes were affiliated with Crenarchaeota (76%) and Euryarchaeota (24%), respectively. Deep-sea archaeal group (DSAG, 41% of total clones) and miscellaneous crenarchaeotic group (MCG, 29% of total clones) belonging to Crenarchaeota were the most predominant archaeal 16S rDNA phylotypes in clone libraries. Phylotypes in this study shared high similarity with those in subsurface sediments from Peru Margin sites, which indicated that different geographical zones might host similar members of archaeal populations based on similar sedimentary environments. In our study, members of DSAG and MCG seemed to dominate certain layers of the nonhydrate sediments, suggesting a wide ecophysiological adaptation than previously appreciated. The spatial distribution and community structure of these groups might vary with the different geochemical gradients of the environment.
authors.affiliation: Key Laboratory of Marine Geology and Environment,Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China. zw2326cs@163.com
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Gaowa
authors.initials: G
authors.lastname: Saren
authors.forename: Tiegang
authors.initials: T
authors.lastname: Li
authors.forename: Xinke
authors.initials: X
authors.lastname: Yu
authors.forename: Linbao
authors.initials: L
authors.lastname: Zhang
mesh_terms: D001483:Base Sequence; D044822:Biodiversity; D019615:Crenarchaeota / Q000145:classification* / Q000235:genetics; D019641:DNA, Archaeal / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D019605:Euryarchaeota / Q000145:classification* / Q000235:genetics; D015723:Gene Library; D019015:Geologic Sediments / Q000382:microbiology*; D010140:Pacific Ocean; D010568:Peru; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014329:Tropical Climate
chemical_list: D019641:DNA, Archaeal; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S