Comparative Analysis of Microbial Diversity Across Temperature Gradients in Hot Springs From Yellowstone and Iceland

• Published in: Frontiers in Microbiology
• Main Authors: Podar, Peter T., Yang, Zamin, Björnsdóttir, Snædís, Podar, Mircea
• Other Authors: Líf- og umhverfisvísindadeild (HÍ), Faculty of Life and Environmental Sciences (UI), Verkfræði- og náttúruvísindasvið (HÍ), School of Engineering and Natural Sciences (UI), Háskóli Íslands, University of Iceland
• Format: Article in Journal/Newspaper
• Language: English
• Published: Frontiers Media SA 2020
• Subjects: Biogeography; Hot springs; Microbial ecology; rRNA amplicons; Thermophiles; Líflandafræði; Hverir; Örverur; Gonzalez; Iceland
• Online Access: https://hdl.handle.net/20.500.11815/2300; https://doi.org/10.3389/fmicb.2020.01625

Publisher's version (útgefin grein) Geothermal hot springs are a natural setting to study microbial adaptation to a wide range of temperatures reaching up to boiling. Temperature gradients lead to distinct microbial communities that inhabit their optimum niches. We sampled three alkaline, high temperature (80–100°C) hot springs in Yellowstone and Iceland that had cooling outflows and whose microbial communities had not been studied previously. The microbial composition in sediments and mats was determined by DNA sequencing of rRNA gene amplicons. Over three dozen phyla of Archaea and Bacteria were identified, representing over 1700 distinct organisms. We observed a significant non-linear reduction in the number of microbial taxa as the temperature increased from warm (38°C) to boiling. At high taxonomic levels, the community structure was similar between the Yellowstone and Iceland hot springs. We identified potential endemism at the genus level, especially in thermophilic phototrophs, which may have been potentially driven by distinct environmental conditions and dispersal limitations. Environmental sampling in Iceland was under permits issued by Iceland?s National Energy Authority (Orkustofnun) to MP and SB. We thank Dr. Jakob Kristj?nsson for help with sampling and permits. Sampling in Yellowstone National Park was under permit YELL-SCI-5714 and we thank Stacey Gunther for help with sampling coordinating. We thank Adrian Gonzalez from The University of Tennessee Knoxville Water Quality Core Facility for chemical analysis of the water samples. Funding. This research was funded in part by grants from the National Science Foundation (DEB1134877) and the National Aeronautics and Space Administration (NNX16AJ66G). Oak Ridge National Laboratory is managed by UT-Battelle, LLC, for the United States Department of Energy under contract DE-AC05-00OR22725. Peer Reviewed