title: Physiological and evolutionary potential of microorganisms from the Canterbury Basin subseafloor, a metagenomic approach.
abstract: Subseafloor sediments represent a large reservoir of organic matter and are inhabited by microbial groups of the three domains of life. Besides impacting the planetary geochemical cycles, the subsurface biosphere remains poorly understood, notably questions related to possible metabolic pathways and selective advantages that may be deployed by buried microorganisms (sporulation, response to stress, dormancy). In order to better understand physiological potentials and possible lifestyles of subseafloor microbial communities, we analyzed two metagenomes from subseafloor sediments collected at 31 mbsf (meters below the sea floor) and 136 mbsf in the Canterbury Basin. Metagenomic phylogenetic and functional diversities were very similar. Phylogenetic diversity was mostly represented by Chloroflexi, Firmicutes and Proteobacteria for Bacteria and by Thaumarchaeota and Euryarchaeota for Archaea. Predicted anaerobic metabolisms encompassed fermentation, methanogenesis and utilization of fatty acids, aromatic and halogenated substrates. Potential processes that may confer selective advantages for subsurface microorganisms included sporulation, detoxication equipment or osmolyte accumulation. Annotation of genomic fragments described the metabolic versatility of Chloroflexi, Miscellaneous Crenarchaeotic Group and Euryarchaeota and showed frequent recombination events within subsurface taxa. This study confirmed that the subseafloor habitat is unique compared to other habitats at the (meta)-genomic level and described physiological potential of still uncultured groups.
authors: CNRS, Centre de Biophysique Moléculaire, Imagerie Spectroscopie et Chimie du Vivant rue Charles Sadron Orléans, FR 45071 Cedex2, France.
authors: Frédéric
authors: F
authors: Gaboyer
authors: Université de Brest, UEB, Laboratoire Universitaire de Biodiversité et d'Écologie Microbienne EA 3882n IFR 148 SFR ScInBioS, ESIAB, Plouzané, France.
authors: Gaëtan
authors: G
authors: Burgaud
authors: CNRS, IUEM - UMR 6197, Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), rue Dumont d'Urville, F-29280 Plouzané, France Ifremer, UMR6197, Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), Technopôle Pointe du diable, F-29280 Plouzané, France Université de Bretagne Occidentale (UBO, UEB), Institut Universitaire Européen de la Mer (IUEM) - UMR 6197, Laboratoire de Microbiologie des Environnements Extrêmes (LMEE), rue Dumont d'Urville, F-29280 Plouzané, France karine.alain@univ-brest.fr.
authors: Karine
authors: K
authors: Alain
mesh_terms: D005075:Biological Evolution; D041862:Chloroflexi / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D017753:Ecosystem; D019605:Euryarchaeota / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D019143:Evolution, Molecular; D020745:Genome, Archaeal / Q000235:genetics; D016680:Genome, Bacterial / Q000235:genetics; D019015:Geologic Sediments / Q000382:microbiology*; D054892:Metagenome / Q000235:genetics*; D009520:New Zealand; D009792:Oceans and Seas; D010140:Pacific Ocean; D010802:Phylogeny; D020560:Proteobacteria / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012338:RNA, Ribosomal, 23S / Q000235:genetics
chemical_list: D012336:RNA, Ribosomal, 16S; D012338:RNA, Ribosomal, 23S
keywords: metagenomics; microbial diversity; microbial physiology; selective advantages; subsurface microbiology