title: A three-scale analysis of bacterial communities involved in rocks colonization and soil formation in high mountain environments.
abstract: Alpha and beta diversities of the bacterial communities growing on rock surfaces, proto-soils, riparian sediments, lichen thalli, and water springs biofilms in a glacier foreland were studied. We used three molecular based techniques to allow a deeper investigation at different taxonomic resolutions: denaturing gradient gel electrophoresis, length heterogeneity-PCR, and automated ribosomal intergenic spacer analysis. Bacterial communities were mainly composed of Acidobacteria, Proteobacteria, and Cyanobacteria with distinct variations among sites. Proteobacteria were more represented in sediments, biofilms, and lichens; Acidobacteria were mostly found in proto-soils; and Cyanobacteria on rocks. Firmicutes and Bacteroidetes were mainly found in biofilms. UniFrac P values confirmed a significant difference among different matrices. Significant differences (P < 0.001) in beta diversity were observed among the different matrices at the genus-species level, except for lichens and rocks which shared a more similar community structure, while at deep taxonomic resolution two distinct bacterial communities between lichens and rocks were found.
authors.affiliation: Faculty of Science and Technology, Free University of Bozen-Bolzano, Piazza Università 5, 39100 Bolzano, Italy.
authors.forename: Alfonso
authors.initials: A
authors.lastname: Esposito
authors.forename: Sonia
authors.initials: S
authors.lastname: Ciccazzo
authors.forename: Luigimaria
authors.initials: L
authors.lastname: Borruso
authors.forename: Stefan
authors.initials: S
authors.lastname: Zerbe
authors.forename: Daniele
authors.initials: D
authors.lastname: Daffonchio
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Brusetti
mesh_terms: D000531:Altitude; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D044822:Biodiversity; D019015:Geologic Sediments / Q000382:microbiology*; D010802:Phylogeny; D012988:Soil Microbiology