title: Phylogenetic diversity of a microbialite reef in a cold alkaline freshwater lake.
abstract: A culture-independent multidomain survey of biodiversity in microbialite structures within the cold alkaline Pavilion Lake (British Columbia, Canada) revealed a largely homogenous community at depths from 10 to 30 m. Real-time quantitative PCR was used to demonstrate that bacteria comprised approximately 80%-95% of recoverable phylotypes. Archaeal phylotypes accounted for <5% of the community in microbialites exposed to the water column, while structures in sediment contact supported 4- to 5-fold higher archaeal abundance. Eukaryal phylotypes were rare and indicated common aquatic diatoms that were concluded not to be part of the microbialite community. Phylogenetic analysis of rRNA genes from clone libraries (N = 491) revealed that alphaproteobacterial phylotypes were most abundant. Cyanobacterial phylotypes were highly diverse but resolved into 4 dominant genera: Acaryochloris, Leptolyngbya, Microcoleus, and Pseudanabaena. Interestingly, microbialite cyanobacteria generally affiliated phylogenetically with aquatic and coral cyanobacterial groups rather than those from stromatolites. Other commonly encountered bacterial phylotypes were from members of the Acidobacteria, with relatively low abundance of the Betaproteobacteria, Chloroflexi, Nitrospirae, and Planctomycetes. Archaeal diversity (N = 53) was largely accounted for by Euryarchaeota, with most phylotypes affiliated with freshwater methanogenic taxa.
authors.affiliation: a Institute for Applied Ecology New Zealand, School of Applied Sciences, Auckland University of Technology, Auckland, New Zealand.
authors.forename: Olivia W
authors.initials: OW
authors.lastname: Chan
authors.forename: Donnabella C
authors.initials: DC
authors.lastname: Bugler-Lacap
authors.forename: Jennifer F
authors.initials: JF
authors.lastname: Biddle
authors.forename: Darlene S
authors.initials: DS
authors.lastname: Lim
authors.forename: Christopher P
authors.initials: CP
authors.lastname: McKay
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Pointing
mesh_terms: D001105:Archaea / Q000145:classification* / Q000235:genetics; D001419:Bacteria / Q000145:classification* / Q000235:genetics; D001483:Base Sequence; D044822:Biodiversity; D001955:British Columbia; D003080:Cold Temperature; D000458:Cyanobacteria / Q000145:classification / Q000235:genetics; D019641:DNA, Archaeal / Q000737:chemistry / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D019605:Euryarchaeota / Q000145:classification / Q000235:genetics; D020459:Genes, rRNA; D006863:Hydrogen-Ion Concentration; D060106:Lakes / Q000737:chemistry / Q000382:microbiology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D019641:DNA, Archaeal; D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S
keywords: Pavilion Lake; biomineralization; biominéralisation; cyanobacteria; cyanobactéries; lac Pavilion; microbialite; reefs; récifs