title: Yellowstone Lake: high-energy geochemistry and rich bacterial diversity.
abstract: Yellowstone Lake is central to the balanced functioning of the Yellowstone ecosystem, yet little is known about the microbial component of its food chain. A remotely operated vehicle provided video documentation (http://www.tbi.montana.edu/media/videos/) and allowed sampling of dilute surface zone waters and enriched lake floor hydrothermal vent fluids. Vent emissions contained substantial H(2)S, CH(4), CO(2) and H(2), although CH(4) and H(2) levels were also significant throughout the lake. Pyrosequencing and near full-length sequencing of Bacteria 16S rRNA gene diversity associated with two vents and two surface water environments demonstrated that this lake contains significant bacterial diversity. Biomass was size-fractionated by sequentially filtering through 20-µm-, 3.0-µm-, 0.8-µm- and 0.1-µm-pore-size filters, with the >0.1 to <0.8 µm size class being the focus of this study. Major phyla included Acidobacteria, Actinobacteria, Bacteroidetes, α- and β-Proteobacteria and Cyanobacteria, with 21 other phyla represented at varying levels. Surface waters were dominated by two phylotypes: the Actinobacteria freshwater acI group and an α-Proteobacteria clade tightly linked with freshwater SAR11-like organisms. We also obtained evidence of novel thermophiles and recovered Prochlorococcus phylotypes (97-100% identity) in one near surface photic zone region of the lake. The combined geochemical and microbial analyses suggest that the foundation of this lake's food chain is not simple. Phototrophy presumably is an important driver of primary productivity in photic zone waters; however, chemosynthetic hydrogenotrophy and methanotrophy are likely important components of the lake's food chain.
authors: Thermal Biology Institute, Montana State University, Bozeman, MT 59717, USA.
authors: Scott
authors: S
authors: Clingenpeel
authors: Richard E
authors: RE
authors: Macur
authors: Jinjun
authors: J
authors: Kan
authors: William P
authors: WP
authors: Inskeep
authors: Dave
authors: D
authors: Lovalvo
authors: John
authors: J
authors: Varley
authors: Eric
authors: E
authors: Mathur
authors: Kenneth
authors: K
authors: Nealson
authors: Yuri
authors: Y
authors: Gorby
authors: Hongchen
authors: H
authors: Jiang
authors: Toben
authors: T
authors: LaFracois
authors: Timothy R
authors: TR
authors: McDermott
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000235:genetics; D044822:Biodiversity; D017753:Ecosystem; D060086:Hydrothermal Vents / Q000737:chemistry / Q000382:microbiology; D060106:Lakes / Q000737:chemistry / Q000382:microbiology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D012336:RNA, Ribosomal, 16S