title: Taxonomic and functional metagenomic profiling of the microbial community in the anoxic sediment of a sub-saline shallow lake (Laguna de Carrizo, Central Spain).
abstract: The phylogenetic and functional structure of the microbial community residing in a Ca(2+)-rich anoxic sediment of a sub-saline shallow lake (Laguna de Carrizo, initially operated as a gypsum (CaSO(4) × 2 H(2)O) mine) was estimated by analyzing the diversity of 16S rRNA amplicons and a 3.1 Mb of consensus metagenome sequence. The lake has about half the salinity of seawater and possesses an unusual relative concentration of ions, with Ca(2+) and SO                            (4)                                      (2-)                          being dominant. The 16S rRNA sequences revealed a diverse community with about 22% of the bacterial rRNAs being less than 94.5% similar to any rRNA currently deposited in GenBank. In addition to this, about 79% of the archaeal rRNA genes were mostly related to uncultured Euryarchaeota of the CCA47 group, which are often associated with marine and oxygen-depleted sites. Sequence analysis of assembled genes revealed that 23% of the open reading frames of the metagenome library had no hits in the database. Among annotated genes, functions related to (thio) sulfate and (thio) sulfonate-reduction and iron-oxidation, sulfur-oxidation, denitrification, synthrophism, and phototrophic sulfur metabolism were found as predominant. Phylogenetic and biochemical analyses indicate that the inherent physical-chemical characteristics of this habitat coupled with adaptation to anthropogenic activities have resulted in a highly efficient community for the assimilation of polysulfides, sulfoxides, and organosulfonates together with nitro-, nitrile-, and cyanide-substituted compounds. We discuss that the relevant microbial composition and metabolic capacities at Laguna de Carrizo, likely developed as an adaptation to thrive in the presence of moderate salinity conditions and potential toxic bio-molecules, in contrast with the properties of previously known anoxic sediments of shallow lakes.
authors: CSIC, Institute of Catalysis, 28049 Madrid, Spain. mferrer@icp.csic.es
authors: Manuel
authors: M
authors: Ferrer
authors: María-Eugenia
authors: ME
authors: Guazzaroni
authors: Michael
authors: M
authors: Richter
authors: Adela
authors: A
authors: García-Salamanca
authors: Pablo
authors: P
authors: Yarza
authors: Ana
authors: A
authors: Suárez-Suárez
authors: Jennifer
authors: J
authors: Solano
authors: María
authors: M
authors: Alcaide
authors: Pieter
authors: P
authors: van Dillewijn
authors: Maria Antonia
authors: MA
authors: Molina-Henares
authors: Nieves
authors: N
authors: López-Cortés
authors: Yamal
authors: Y
authors: Al-Ramahi
authors: Carmen
authors: C
authors: Guerrero
authors: Alejandro
authors: A
authors: Acosta
authors: Laura I
authors: LI
authors: de Eugenio
authors: Virginia
authors: V
authors: Martínez
authors: Silvia
authors: S
authors: Marques
authors: Fernando
authors: F
authors: Rojo
authors: Eduardo
authors: E
authors: Santero
authors: Olga
authors: O
authors: Genilloud
authors: Julian
authors: J
authors: Pérez-Pérez
authors: Ramón
authors: R
authors: Rosselló-Móra
authors: Juan Luis
authors: JL
authors: Ramos
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics*; D019641:DNA, Archaeal / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D019605:Euryarchaeota / Q000145:classification / Q000235:genetics*; D015723:Gene Library; D019015:Geologic Sediments / Q000382:microbiology*; D060106:Lakes / Q000382:microbiology; D054892:Metagenome; D008969:Molecular Sequence Data; D009584:Nitrogen / Q000378:metabolism; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013030:Spain; D013455:Sulfur / Q000378:metabolism
chemical_list: D019641:DNA, Archaeal; D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D013455:Sulfur; D009584:Nitrogen