title: Comparison of Prokaryotic Diversity in Cold, Oligotrophic Remote Lakes of Chilean Patagonia.
abstract: The prokaryotic abundance and diversity in three cold, oligotrophic Patagonian lakes (Témpanos, Las Torres and Mercedes) in the northern region Aysén (Chile) were compared in winter and summer using 16S rRNA fluorescence in situ hybridization and PCR-denaturing gradient gel electrophoresis technique. Prokaryotic abundances, numerically dominated by Bacteria, were quite similar in the three lakes, but higher in sediments than in waters, and they were also higher in summer than in winter. The relative contribution of Archaea was greater in waters than in sediments, and in winter rather than in summer. Despite the phylogenetic analysis indicated that most sequences were affiliated to a few taxonomic groups, mainly referred to Proteobacteria (consisting of Beta-, Alpha- and Gammaproteobacteria) and Euryarchaeota (mainly related to uncultured methanogens), their relative abundances differed in each sample, resulting in different bacterial and archaeal assemblages. In winter, the abundance of the dominant bacterial phylotypes were mainly regulated by the increasing levels of total organic carbon in waters. Archaeal abundance and richness appeared mostly influenced by pH in winter and total nitrogen content in summer. The prokaryotic community composition at Témpanos lake, located most northerly and closer to a glacier, greatly differed in respect to the other two lakes. In this lake was detected the highest bacterial diversity, being Betaproteobacteria the most abundant group, whereas Alphaproteobacteria were distinctive of Mercedes. Archaeal community associated with sediments was mainly represent by members related to the order of Methanosarcinales at Mercedes and Las Torres lakes, and by Crenarchaeota at Témpanos lake. Our results indicate that the proximity to the glacier and the seasonality shape the composition of the prokaryotic communities in these remote lakes. These results may be used as baseline information to follow the microbial community responses to potential global changes and to anthropogenic impacts.
authors.affiliation: Department of Microbiology, Laboratory of Basic Microbiology and Bioremedation, University of Concepción, Concepción, Chile.|Research Centre for Extreme Environments and Extremophiles, Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, V.le F. Stagno d'Alcontres, 31, 98166, Messina, Italy.
authors.forename: Paulina
authors.initials: P
authors.lastname: Aguayo
authors.affiliation: Department of Microbiology, Laboratory of Basic Microbiology and Bioremedation, University of Concepción, Concepción, Chile.
authors.forename: Paulina
authors.initials: P
authors.lastname: González
authors.affiliation: Research Centre for Extreme Environments and Extremophiles, Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, V.le F. Stagno d'Alcontres, 31, 98166, Messina, Italy.|Department of Microbiology, Laboratory of Environmental Microbiology, University of Concepción, Concepción, Chile.
authors.forename: Víctor
authors.initials: V
authors.lastname: Campos
authors.affiliation: Research Centre for Extreme Environments and Extremophiles, Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, V.le F. Stagno d'Alcontres, 31, 98166, Messina, Italy.
authors.forename: Teresa L
authors.initials: TL
authors.lastname: Maugeri
authors.affiliation: Research Centre for Extreme Environments and Extremophiles, Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, V.le F. Stagno d'Alcontres, 31, 98166, Messina, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Papale
authors.affiliation: Research Centre for Extreme Environments and Extremophiles, Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, V.le F. Stagno d'Alcontres, 31, 98166, Messina, Italy. cgugliandolo@unime.it.
authors.forename: Concetta
authors.identifier: http://orcid.org/0000-0002-9125-3999
authors.initials: C
authors.lastname: Gugliandolo
authors.affiliation: Department of Microbiology, Laboratory of Basic Microbiology and Bioremedation, University of Concepción, Concepción, Chile.|Research Centre for Extreme Environments and Extremophiles, Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, V.le F. Stagno d'Alcontres, 31, 98166, Messina, Italy.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Martinez
mesh_terms: D001105:Archaea / Q000145:classification / Q000235:genetics; D001419:Bacteria / Q000145:classification / Q000235:genetics; D044822:Biodiversity; D002677:Chile; D004777:Environment; D005843:Geography; D019015:Geologic Sediments / Q000737:chemistry / Q000382:microbiology; D060106:Lakes / Q000737:chemistry / Q000382:microbiology*; D010802:Phylogeny; D011387:Prokaryotic Cells / Q000145:classification*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012621:Seasons; D014871:Water Microbiology
chemical_list: D012336:RNA, Ribosomal, 16S