title: Diversity and Assembling Processes of Bacterial Communities in Cryoconite Holes of a Karakoram Glacier.
abstract: Cryoconite holes are small ponds that form on the surface of glaciers that contain a dark debris, the cryoconite, at the bottom and host active ecological communities. Differences in the structure of bacterial communities have been documented among Arctic and mountain glaciers, and among glaciers in different areas of the world. In this study, we investigated the structure of bacterial communities of cryoconite holes of Baltoro Glacier, a large (62 km in length and 524 km2of surface) glacier of the Karakoram, by high-throughput sequencing of the V5-V6 hypervariable regions of the 16S rRNA gene. We found that Betaproteobacteria dominated bacterial communities, with large abundance of genera Polaromonas, probably thanks to its highly versatile metabolism, and Limnohabitans, which may have been favoured by the presence of supraglacial lakes in the area where cryoconite holes were sampled. Variation in bacterial communities among different sampling areas of the glacier could be explained by divergent selective processes driven by variation in environmental conditions, particularly pH, which was the only environmental variable that significantly affected the structure of bacterial communities. This variability may be due to both temporal and spatial patterns of variation in environmental conditions.
authors.affiliation: Dept. of Earth and Environmental Sciences (DISAT), University of Milano-Bicocca, Piazza della Scienza 1, 20126, Milan, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Ambrosini
authors.affiliation: Dept. of Earth and Environmental Sciences (DISAT), University of Milano-Bicocca, Piazza della Scienza 1, 20126, Milan, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Musitelli
authors.affiliation: Dept. of Earth and Environmental Sciences (DISAT), University of Milano-Bicocca, Piazza della Scienza 1, 20126, Milan, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Navarra
authors.affiliation: Dept. of Earth and Environmental Sciences (DISAT), University of Milano-Bicocca, Piazza della Scienza 1, 20126, Milan, Italy.
authors.forename: Ilario
authors.initials: I
authors.lastname: Tagliaferri
authors.affiliation: Dept. of Earth and Environmental Sciences (DISAT), University of Milano-Bicocca, Piazza della Scienza 1, 20126, Milan, Italy.
authors.forename: Isabella
authors.initials: I
authors.lastname: Gandolfi
authors.affiliation: Dept. of Earth and Environmental Sciences (DISAT), University of Milano-Bicocca, Piazza della Scienza 1, 20126, Milan, Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Bestetti
authors.affiliation: Bavarian Academy of Sciences and Humanities, Munich, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Mayer
authors.affiliation: "A. Desio" Dept. of Earth Sciences, Università degli Studi di Milano, Milan, Italy.
authors.forename: Umberto
authors.initials: U
authors.lastname: Minora
authors.affiliation: "A. Desio" Dept. of Earth Sciences, Università degli Studi di Milano, Milan, Italy.
authors.forename: Roberto Sergio
authors.initials: RS
authors.lastname: Azzoni
authors.affiliation: "A. Desio" Dept. of Earth Sciences, Università degli Studi di Milano, Milan, Italy.
authors.forename: Guglielmina
authors.initials: G
authors.lastname: Diolaiuti
authors.affiliation: "A. Desio" Dept. of Earth Sciences, Università degli Studi di Milano, Milan, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Smiraglia
authors.affiliation: Dept. of Earth and Environmental Sciences (DISAT), University of Milano-Bicocca, Piazza della Scienza 1, 20126, Milan, Italy. andrea.franzetti@unimib.it.
authors.forename: Andrea
authors.identifier: 0000-0003-1279-9940
authors.initials: A
authors.lastname: Franzetti
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D044822:Biodiversity; D058448:Biota; D004269:DNA, Bacterial; D017753:Ecosystem; D005798:Genes, Bacterial; D057166:High-Throughput Screening Assays / Q000379:methods; D006863:Hydrogen-Ion Concentration; D046448:Ice Cover / Q000382:microbiology*; D060106:Lakes / Q000382:microbiology; D059013:Microbial Consortia; D010154:Pakistan; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S
keywords: Bacterial communities; Baltoro glacier; Cryoconite; Cryosphere; Dispersal