title: Metagenomic analysis of hadopelagic microbial assemblages thriving at the deepest part of Mediterranean Sea, Matapan-Vavilov Deep.
abstract: The marine pelagic zone situated > 200 m below the sea level (bls) is the largest marine subsystem, comprising more than two-thirds of the oceanic volume. At the same time, it is one of the least explored ecosystems on Earth. Few large-scale environmental genomics studies have been undertaken to examine the phylogenetic diversity and functional gene repertoire of planktonic microbes present in mesopelagic and bathypelagic environments. Here, we present the description of the deep-sea microbial community thriving at > 4900 m depth in Matapan-Vavilov Deep (MVD). This canyon is the deepest site of Mediterranean Sea, with a deepest point located at approximately 5270 m, 56 km SW of city Pylos (Greece) in the Ionian Sea (36°34.00N, 21°07.44E). Comparative analysis of whole-metagenomic data revealed that unlike other deep-sea metagenomes, the prokaryotic diversity in MVD was extremely poor. The decline in the dark primary production rates, measured at 4908 m depth, was coincident with overwhelming dominance of copiotrophic Alteromonas macleodii'deep-ecotype' AltDE at the expense of other prokaryotes including those potentially involved in both autotrophic and anaplerotic CO(2) fixation. We also demonstrate the occurrence in deep-sea metagenomes of several clustered regularly interspaced short palindromic repeats systems.
authors: Institute for Coastal Marine Environment, CNR, Spianata S.Raineri 86, 98122 Messina, Italy.
authors: Francesco
authors: F
authors: Smedile
authors: Enzo
authors: E
authors: Messina
authors: Violetta
authors: V
authors: La Cono
authors: Olga
authors: O
authors: Tsoy
authors: Luis S
authors: LS
authors: Monticelli
authors: Mireno
authors: M
authors: Borghini
authors: Laura
authors: L
authors: Giuliano
authors: Peter N
authors: PN
authors: Golyshin
authors: Arcady
authors: A
authors: Mushegian
authors: Michail M
authors: MM
authors: Yakimov
mesh_terms: D020591:Alteromonas / Q000145:classification / Q000201:enzymology / Q000235:genetics*; D001105:Archaea / Q000145:classification / Q000201:enzymology / Q000235:genetics*; D052818:Autotrophic Processes; D044822:Biodiversity; D017753:Ecosystem; D004783:Environmental Microbiology; D006115:Greece; D008522:Mediterranean Sea; D054892:Metagenome; D056186:Metagenomics; D009792:Oceans and Seas; D010802:Phylogeny; D012623:Seawater / Q000382:microbiology; D014780:Viruses / Q000145:classification / Q000235:genetics