title: Microbial survival: the paleome: a sedimentary genetic record of past microbial communities.
abstract: Molecular genetic methods were used to analyze the remnants of microbial ecosystems contained within an ancient oceanic microbial habitat that was recovered from a continental drilled core of black shale approximately 100 million years in age. Bacterial ribosomal RNA genes were vertically amplified from the six different depths of a black shale core associated with a phosphate-rich stratum, defined as one of the mid-Cretaceous oceanic anoxic events (OAEs). Although the black shale core was recovered from a terrestrial coring effort, the recovered 16S rRNA gene sequences showed affinity to microbial communities previously seen in deep-sea sedimentary environments (i.e., the microbial assemblage was easily recognizable as a marine community). In particular, a number of 16S rRNA gene clones of oceanic sulfate-reducing bacteria within the delta-Proteobacteria predominated at the OAE layer. The recovered bacterial DNA signatures are consistent with the interpretation that the sequences are derived from the past microbial communities buried in either sea-bottom or subseafloor environments during the sedimentation process and, after ceasing growth, preserved until the present.
authors.affiliation: Subground Animalcule Retrieval (SUGAR) Project, Extremobiosphere Research Center, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan.
authors.forename: Fumio
authors.initials: F
authors.lastname: Inagaki
authors.forename: Hisatake
authors.initials: H
authors.lastname: Okada
authors.forename: Alexandre I
authors.initials: AI
authors.lastname: Tsapin
authors.forename: Kenneth H
authors.initials: KH
authors.lastname: Nealson
mesh_terms: D001419:Bacteria / Q000235:genetics* / Q000254:growth & development*; D016172:DNA Fingerprinting; D004269:DNA, Bacterial; D005580:Fossils; D016680:Genome, Bacterial; D019015:Geologic Sediments / Q000382:microbiology*; D008969:Molecular Sequence Data; D010163:Paleontology; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000032:analysis
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S