These authors contributed equally to the work.
Spatial and temporal variability of biomarkers and microbial diversity reveal metabolic and community flexibility in Streamer Biofilm Communities in the Lower Geyser Basin, Yellowstone National Park
Article first published online: 28 AUG 2013
© 2013 John Wiley & Sons Ltd
Volume 11, Issue 6, pages 549–569, November 2013
How to Cite
Schubotz, F., Meyer-Dombard, D. R., Bradley, A. S., Fredricks, H. F., Hinrichs, K.-U., Shock, E. L. and Summons, R. E. (2013), Spatial and temporal variability of biomarkers and microbial diversity reveal metabolic and community flexibility in Streamer Biofilm Communities in the Lower Geyser Basin, Yellowstone National Park. Geobiology, 11: 549–569. doi: 10.1111/gbi.12051
- Issue published online: 11 OCT 2013
- Article first published online: 28 AUG 2013
- Manuscript Accepted: 19 JUL 2013
- Manuscript Received: 8 AUG 2012
- NSF Biogeosciences Program. Grant Number: 0525453
- NASA Astrobiology Institute
- Feodor Lynen fellowship of the Alexander von Humboldt Foundation and the NASA Astrobiology Institute
Detailed analysis of 16S rRNA and intact polar lipids (IPLs) from streamer biofilm communities (SBCs), collected from geochemically similar hot springs in the Lower Geyser Basin, Yellowstone National Park, shows good agreement and affirm that IPLs can be used as reliable markers for the microbial constituents of SBCs. Uncultured Crenarchaea are prominent in SBS, and their IPLs contain both glycosidic and mixed glyco-phospho head groups with tetraether cores, having 0–4 rings. Archaeal IPL contributions increase with increasing temperature and comprise up to one-fourth of the total IPL inventory at >84 °C. At elevated temperatures, bacterial IPLs contain abundant glycosidic glycerol diether lipids. Diether and diacylglycerol (DAG) lipids with aminopentanetetrol and phosphatidylinositol head groups were identified as lipids diagnostic of Aquificales, while DAG glycolipids and glyco-phospholipids containing N-acetylgycosamine as head group were assigned to members of the Thermales. With decreasing temperature and concomitant changes in water chemistry, IPLs typical of phototrophic bacteria, such as mono-, diglycosyl, and sulfoquinovosyl DAG, which are specific for cyanobacteria, increase in abundance, consistent with genomic data from the same samples. Compound-specific stable carbon isotope analysis of IPL breakdown products reveals a large isotopic diversity among SBCs in different hot springs. At two of the hot springs, ‘Bison Pool’ and Flat Cone, lipids derived from Aquificales are enriched in 13C relative to biomass and approach values close to dissolved inorganic carbon (DIC) (approximately 0‰), consistent with fractionation during autotrophic carbon fixation via the reversed tricarboxylic acid pathway. At a third site, Octopus Spring, the same Aquificales-diagnostic lipids are 10‰ depleted relative to biomass and resemble stable carbon isotope values of dissolved organic carbon (DOC), indicative of heterotrophy. Other bacterial and archaeal lipids show a similar variance, with values resembling the DIC or DOC pool or a mixture thereof. This variance cannot be explained by hot spring chemistry or temperature alone, but instead, we argue that intermittent input of exogenous organic carbon can result in metabolic shifts of the chemotrophic communities from autotrophy to heterotrophy and vice versa.