Lipid biomarker and carbon isotopic signatures for stromatolite-forming, microbial mat communities and Phormidium cultures from Yellowstone National Park

ABSTRACTKnallgas bacteria are a physiologically defined group that is primarily studied using cultivation-dependent techniques. Given that current cultivation techniques fail to grow most bacteria, cultivation-independent techniques that selectively detect and identify knallgas bacteria will improve our ability to study their diversity and distribution. We used stable-isotope probing (SIP) to identify knallgas bacteria in rhizosphere soil of legumes and in a microbial mat from Obsidian Pool in Yellowstone National Park. When samples were incubated in the dark, incorporation of13CO2was H2dependent. SIP enabled the detection of knallgas bacteria that were not detected by cultivation, and the majority of bacteria identified in the rhizosphere soils were betaproteobacteria predominantly related to genera previously known to oxidize hydrogen. Bacteria in soil grew on hydrogen at concentrations as low as 100 ppm. AhydBhomolog encoding a putative high-affinity NiFe hydrogenase was amplified from13C-labeled DNA from both vetch and clover rhizosphere soil. The results indicate that knallgas bacteria can be detected by SIP and populations that respond to different H2concentrations can be distinguished. The methods described here should be applicable to a variety of ecosystems and will enable the discovery of additional knallgas bacteria that are resistant to cultivation.

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Impact of carbon metabolism on13C signatures of cyanobacteria and green non-sulfur-like bacteria inhabiting a microbial mat from an alkaline siliceous hot spring in Yellowstone National Park (USA)

Environmental Microbiology ◽

10.1111/j.1462-2920.2006.01165.x ◽

2007 ◽

Vol 9 (2) ◽

pp. 482-491 ◽

Cited By ~ 37

Author(s):

Marcel T. J. van der Meer ◽

Stefan Schouten ◽

Jaap S. Sinninghe Damsté ◽

David M. Ward

Keyword(s):

Carbon Metabolism ◽

Yellowstone National Park ◽

National Park ◽

Hot Spring ◽

Microbial Mat

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Ultrastructural Localization of Phycocyanin in the Acidophilic, Thermophilic Alga, Cyanidium Caldarium

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100072757 ◽

1973 ◽

Vol 31 ◽

pp. 462-463

Author(s):

M. R. Edwards ◽

J. D. Mainwaring

Keyword(s):

Yellowstone National Park ◽

National Park ◽

Ultrastructural Localization ◽

Review Of Literature ◽

Cyanidium Caldarium ◽

Taxonomic Rank ◽

Thin Sections ◽

Standard Methods ◽

Laboratory Cultures

Although the general ultrastructure of Cyanidium caldarium, an acidophilic, thermophilic alga of questionable taxonomic rank, has been extensively studied (see review of literature in reference 1), some peculiar ultrastructural features of the chloroplast of this alga have not been noted by other investigators.Cells were collected and prepared for thin sections at the Yellowstone National Park and were also grown in laboratory cultures (45-52°C; pH 2-5). Fixation (glutaraldehyde-osmium), dehydration (ethanol), and embedding (Epon 812) were accomplished by standard methods. Replicas of frozenfracture d- etched cells were obtained in a Balzers apparatus. In addition, cells were examined after disruption in a French Press.

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