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Item Naegleria fowleri Detected in Grand Teton National Park Hot Springs(American Chemical Society, 2024-01) Barnhart, Elliot P.; Kinsey, Stacey M.; Wright, Peter R.; Caldwell, Sara L.; Hill, Vince; Kahler, Amy; Mattioli, Mia; Cornman, Robert S.; Iwanowicz, Deborah; Eddy, Zachary; Halonen, Sandra; Mueller, Rebecca; Peyton, Brent M.; Puzon, Geoffrey J.The free-living thermophilic amoeba Naegleria fowleri (N. fowleri) causes the highly fatal disease primary amoebic meningoencephalitis. The environmental conditions that are favorable to the growth and proliferation of N. fowleri are not well-defined, especially in northern regions of the United States. In this study, we used culture-based methods and multiple molecular approaches to detect and analyzeN. fowleri and other Naegleria spp. in water, sediment, and biofilm samples from five hot spring sites in Grand Teton National Park, Wyoming, U.S.A. These results provide the first detections of N. fowleri in Grand Teton National Park and provide new insights into the distribution of pathogenic N. fowleri and other nonpathogenic Naegleria spp. in natural thermal water systems in northern latitudes.Item Diversity and function of methyl-coenzyme M reductase-encoding archaea in Yellowstone hot springs revealed by metagenomics and mesocosm experiments(Springer Science and Business Media LLC, 2023-03) Lynes, Mackenzie M.; Krukenberg, Viola; Jay, Zackary J.; Kohtz, Anthony J.; Gobrogge, Christine A.; Lange Spietz, Rachel K.; Hatzenpichler, RolandMetagenomic studies on geothermal environments have been central in recent discoveries on the diversity of archaeal methane and alkane metabolism. Here, we investigated methanogenic populations inhabiting terrestrial geothermal features in Yellowstone National Park (YNP) by combining amplicon sequencing with metagenomics and mesocosm experiments. Detection of methyl-coenzyme M reductase subunit A (mcrA) gene amplicons demonstrated a wide diversity of Mcr-encoding archaea inhabit geothermal features with differing physicochemical regimes across YNP. From three selected hot springs we recovered twelve Mcr-encoding metagenome assembled genomes (MAGs) affiliated with lineages of cultured methanogens as well as Candidatus (Ca.) Methanomethylicia, Ca. Hadesarchaeia, and Archaeoglobi. These MAGs encoded the potential for hydrogenotrophic, aceticlastic, hydrogen-dependent methylotrophic methanogenesis, or anaerobic short-chain alkane oxidation. While Mcr-encoding archaea represent minor fractions of the microbial community of hot springs, mesocosm experiments with methanogenic precursors resulted in the stimulation of methanogenic activity and the enrichment of lineages affiliated with Methanosaeta and Methanothermobacter as well as with uncultured Mcr-encoding archaea including Ca. Korarchaeia, Ca. Nezhaarchaeia, and Archaeoglobi. We revealed that diverse Mcr-encoding archaea with the metabolic potential to produce methane from different precursors persist in the geothermal environments of YNP and can be enriched under methanogenic conditions. This study highlights the importance of combining environmental metagenomics with laboratory-based experiments to expand our understanding of uncultured Mcr-encoding archaea and their potential impact on microbial carbon transformations in geothermal environments and beyond.Item An emerging view of the diversity, ecology and function of Archaea in alkaline hydrothermal environments(Oxford University Press, 2020-12) Mueller, Rebecca C; Peach, Jesse T; Skorupa, Dana J; Copie, Valerie; Bothner, Brian; Peyton, Brent MThe described diversity within the domain Archaea has recently expanded due to advances in sequencing technologies, but many habitats that likely harbor novel lineages of archaea remain understudied. Knowledge of archaea within natural and engineered hydrothermal systems, such as hot springs and engineered subsurface habitats, has been steadily increasing, but the majority of the work has focused on archaea living in acidic or circumneutral environments. The environmental pressures exerted by the combination of high temperatures and high pH likely select for divergent communities and distinct metabolic pathways from those observed in acidic or circumneutral systems. In this review, we examine what is currently known about the archaea found in thermoalkaline environments, focusing on the detection of novel lineages and knowledge of the ecology, metabolic pathways and functions of these populations and communities. We also discuss the potential of emerging multi–omics approaches, including proteomics and metabolomics, to enhance our understanding of archaea within extreme thermoalkaline systems.Item Mantle-derived helium in hot springs of the Cordillera Blanca, Peru: Implications for mantle-to-crust fluid transfer in a flat-slab subduction setting(Elsevier, 2015-12) Newell, Dennis L.; Jessup, Micah J.; Hilton, David R.; Shaw, Colin A.; Hughes, Cameron A.Fault-controlled hot springs in the Cordillera Blanca, Peru provide geochemical evidence of mantle-derived fluids in a modern flat-slab subduction setting. The Cordillera Blanca is an ~ 200 km-long mountain range that contains the highest peaks in the Peruvian Andes, located in an amagmatic reach of the Andean arc. The Cordillera Blanca detachment defines the southwestern edge of the range and records a progression of top-down-to-the-west ductile shear to brittle normal faulting since ~ 5 Ma. Hot springs, recording temperatures up to 78 °C, issue along this fault zone and are CO2-rich, near neutral, alkaline-chloride to alkaline-carbonate waters, with elevated trace metal contents including arsenic (≤ 11 ppm). Water δ18OSMOW (− 14.2 to − 4.9‰) and δDSMOW (− 106.2 to − 74.3‰), trends in elemental chemistry, and cation geothermometry collectively demonstrate mixing of hot (200–260 °C) saline fluid with cold meteoric water along the fault. Helium isotope ratios (3He/4He) for dissolved gases in the waters range from 0.62 to 1.98 RA (where RA = air 3He/4He), indicating the presence of up to 25% mantle-derived helium. Given the long duration since, and large distance to active magmatism in the region, and the possible presence of a tear in the flat slab south of the Cordillera Blanca, we suggest that mantle helium may originate from asthenosphere entering the slab tear, or from the continental mantle-lithosphere, mobilized by metasomatic fluids derived from slab dehydration.