title: Comparative analysis of the microbial communities inhabiting halite evaporites of the Atacama Desert.
abstract: Molecular biology and microscopy techniques were used to characterize the microbial communities inside halite evaporites from different parts of the Atacama Desert. Denaturing gradient gel electrophoresis (DGGE) analysis revealed that the evaporite rocks harbor communities predominantly made up of cyanobacteria, along with heterotrophic bacteria and archaea. Different DGGE profiles were obtained for the different sites, with the exception of the cyanobacterial profile, in which only one phylotype was detected across the three sites examined. Chroococcidiopsis-like cells were the only cyanobacterial components of the rock samples, although the phylogenetic study revealed their closer genetic affinity to Halothece genera. Gene sequences of the heterotrophic bacteria and archaea indicated their proximity to microorganisms found in other hypersaline environments. Microorganisms colonizing these halites formed microbial aggregates in the pore spaces between halite crystals, where microbial interactions occur. In this exceptional, salty, porous halite rock habitat, microbial consortia with a community structure probably conditioned by the environmental conditions occupy special microhabitats with physical and chemical properties that promote their survival.
authors.affiliation: Institute of Natural Resources, CCMA, CSIC, Madrid, Spain. arios@ccma.csic.es
authors.forename: Asunción
authors.initials: A
authors.lastname: de Los Ríos
authors.forename: Sergio
authors.initials: S
authors.lastname: Valea
authors.forename: Carmen
authors.initials: C
authors.lastname: Ascaso
authors.forename: Alfonso
authors.initials: A
authors.lastname: Davila
authors.forename: Jan
authors.initials: J
authors.lastname: Kastovsky
authors.forename: Christopher P
authors.initials: CP
authors.lastname: McKay
authors.forename: Benito
authors.initials: B
authors.lastname: Gómez-Silva
authors.forename: Jacek
authors.initials: J
authors.lastname: Wierzchos
mesh_terms: D001105:Archaea / Q000145:classification* / Q000235:genetics*; D001419:Bacteria / Q000145:classification* / Q000235:genetics*; D044822:Biodiversity; D016000:Cluster Analysis; D019641:DNA, Archaeal / Q000737:chemistry / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D003889:Desert Climate; D004591:Electrophoresis, Polyacrylamide Gel; D020459:Genes, rRNA; D054892:Metagenome; D008853:Microscopy; D009691:Nucleic Acid Denaturation; D010802:Phylogeny; D019642:RNA, Archaeal / Q000235:genetics; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D012988:Soil Microbiology
chemical_list: D019641:DNA, Archaeal; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D019642:RNA, Archaeal; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S