title: Biogeographical distribution and ecological ranges of benthic cyanobacteria in East Antarctic lakes.
abstract: For the first time, the cyanobacterial diversity from microbial mats in lakes of Eastern Antarctica was investigated using microscopic and molecular approaches. The present study assessed the biogeographical distribution of cyanobacteria in Antarctica. Five samples were taken from four lakes spanning a range of different ecological environments in Larsemann Hills, Vestfold Hills and Rauer Islands to evaluate the influence of lake characteristics on the cyanobacterial diversity. Seventeen morphospecies and 28 16S rRNA gene-based operational taxonomic units belonging to the Oscillatoriales, Nostocales and Chroococcales were identified. The internal transcribed spacer was evaluated to complement the 16S rRNA gene data and showed similar but more clear-cut tendencies. The molecular approach suggested that potential Antarctic endemic species, including a previously undiscovered diversity, are more abundant than has been estimated by morphological methods. Moreover, operational taxonomic units, also found outside Antarctica, were more widespread over the continent than potential endemics. The cyanobacterial diversity of the most saline lakes was found to differ from the others, and correlations between the sampling depth and the cyanobacterial communities can also be drawn. Comparison with database sequences illustrated the ubiquity of several cyanobacterial operational taxonomic units and their remarkable range of tolerance to harsh environmental conditions.
authors.affiliation: Laboratoire d'Algologie, de Mycologie et de Systématique Expérimentale, Institut de Botanique B22, Université de Liège, B-4000 Liège, Belgium.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Taton
authors.forename: Stana
authors.initials: S
authors.lastname: Grubisic
authors.forename: Pierre
authors.initials: P
authors.lastname: Balthasart
authors.forename: Dominic A
authors.initials: DA
authors.lastname: Hodgson
authors.forename: Johanna
authors.initials: J
authors.lastname: Laybourn-Parry
authors.forename: Annick
authors.initials: A
authors.lastname: Wilmotte
mesh_terms: D000864:Antarctic Regions; D044822:Biodiversity; D000458:Cyanobacteria / Q000145:classification* / Q000166:cytology / Q000235:genetics / Q000302:isolation & purification*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D017753:Ecosystem; D005618:Fresh Water / Q000382:microbiology*; D005843:Geography; D008853:Microscopy; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D014871:Water Microbiology
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer; D012336:RNA, Ribosomal, 16S