Extremophiles/Astrobiology
Microbial communities in extreme environments and extraterrestrial analogs
To gain a better understanding of the potential for life in extraterrestrial ecosystems, astrobiologists investigate life in extreme environments on Earth. Much of the known universe is cold, dry, and highly irradiated. Here on Earth the most suitable analogs for astrobiology research are those locations that can best approximate these extremes. High elevation and high latitude soil and ice systems are among the best analogs for extraterrestrial sites such as Mars and Europa. There has been much work done at low elevation sites such as in the Dry Valleys of Antarctica and the Atacama Desert, but high elevation sites provide excellent analogs because of the thinner atmosphere, drier air, higher radiation, and more extreme temperature fluctuations. Our lab has focused on how extremophiles cope with dramatic temperature fluctuations across the freezing point, sparse and intermittent water availability, and low nutrient levels encountered in the world's highest mountains such as the Himalayas and Andes (Schmidt et al. 2009, Vimercati et al. 2016) and Himalayas (Schmidt et al. 2011). We also carryout lab and field studies to determine the viability of individual microbes as well as microbial communities in these extreme systems, both from a survival capability and in terms of growth, reproduction, and ecosystem function (e.g. Lynch et al. 2014, Vimercati et al. 2016). Research sites are in Nepal, Chile, Argentina, Tanzania, Colorado, Antarctica, and Perú. Funding for this work has come from several grants from the National Science Foundation, the US Air Force, and through our involvement with the Center for Astrobiology at CU, Boulder.
To gain a better understanding of the potential for life in extraterrestrial ecosystems, astrobiologists investigate life in extreme environments on Earth. Much of the known universe is cold, dry, and highly irradiated. Here on Earth the most suitable analogs for astrobiology research are those locations that can best approximate these extremes. High elevation and high latitude soil and ice systems are among the best analogs for extraterrestrial sites such as Mars and Europa. There has been much work done at low elevation sites such as in the Dry Valleys of Antarctica and the Atacama Desert, but high elevation sites provide excellent analogs because of the thinner atmosphere, drier air, higher radiation, and more extreme temperature fluctuations. Our lab has focused on how extremophiles cope with dramatic temperature fluctuations across the freezing point, sparse and intermittent water availability, and low nutrient levels encountered in the world's highest mountains such as the Himalayas and Andes (Schmidt et al. 2009, Vimercati et al. 2016) and Himalayas (Schmidt et al. 2011). We also carryout lab and field studies to determine the viability of individual microbes as well as microbial communities in these extreme systems, both from a survival capability and in terms of growth, reproduction, and ecosystem function (e.g. Lynch et al. 2014, Vimercati et al. 2016). Research sites are in Nepal, Chile, Argentina, Tanzania, Colorado, Antarctica, and Perú. Funding for this work has come from several grants from the National Science Foundation, the US Air Force, and through our involvement with the Center for Astrobiology at CU, Boulder.
Some relevant publications (Reverse chronological order):
Dragone NB, LB Perry, AJ Solon, A Seimon, TA Seimon, SK Schmidt. 2023. Genetic analysis of the frozen microbiome at 7900 m a.s.l., on the South Col of Sagarmatha (Mount Everest). Arctic Antarctic Alpine Res 55: 2164999 [Press: MongaBay, CU, Outside, Phys.org, AXIOS, CTVnews, ScienceAlert, SciTechDaily, ENN, IndianExpress, Earth.com, IndexJournal]
Solon A, Mastrangelo C, et al. 2022. Gullies and moraines are islands of biodiversity in an arid, mountain landscape, Asgard Range, Antarctica. Frontiers Microbiology 12: 654135. [Reprint]
Schmidt SK, BW Johnson, AJ Solon et al. 2022. Microbial biogeochemistry and phosphorus limitation in cryoconite holes across the Taylor Valley, McMurdo Dry Valleys, Antarctica. Biogeochemistry 158: 313-323. [Reprint]
Hu W, SK Schmidt, P Sommers, JL Darcy, DL Porazinska. 2021. Multi‐trophic patterns of primary succession following retreat of a high‐elevation glacier. Ecosphere 12: e03400. [Reprint]
Vimercati L, CP Bueno de Mesquita, SK Schmidt. 2020. Limited response of indigenous microbes to water and nutrient pulses in high-elevation Atacama soils: Implications for the cold–dry limits of life on Earth. Microorganisms 8: 1061.
Vimercati, L., Darcy, J. L., Schmidt, S. K. 2019. The disappearing periglacial ecosystem atop Mt. Kilimanjaro supports both cosmopolitan and endemic microbial communities. Scientific Reports 9: 1-14.
Schmidt S.K. et al. 2018. Life at extreme elevations on Atacama volcanoes: The closest thing to Mars on Earth? Antonie van Leeuwenhoek 111: 1389–1401.
Solon AJ et al. 2018. Microbial communities of high-elevation fumaroles, penitentes and dry tephra "soils" of the Puna deAtacama Volcanic Zone. Microb Ecol doi.org/10.1007/s00248-017-1129-1
Vimercati L. et al. 2016. Growth of high-elevation Cryptococcus sp. during extreme freeze–thaw cycles. Extremophiles, 20: 579-588. [Reprint]
Lynch R. et al. 2014. Metagenomic evidence for metabolism of trace atmospheric gases by high-elevation desert Actinobacteria. Frontiers Microbiol. 5:698
Rhodes M. et al. 2013. Alpine, Antarctic and Arctic Soil Microbial Communities. in The Prokaryotes (4th ed.), pp. 44-56 (Rosenberg et al., ed.). Springer, Berlin. [Reprint]
Lynch R. et al. 2012. The potential for microbial life in the highest-elevation (6000 m.a.s.l.) mineral soils of the Atacama region. J. Geophysical Res. 117: G02028 [Reprint]
Mladenov N., et al. 2012. Atmospheric deposition as a source of carbon and nutrients to an alpine catchment of the Colorado Rocky Mountains. Biogeosciences 9: 3337-3355 [Reprint]
Schmidt S.K. et al. 2011. Phylogeography of microbial phototrophs in the dry valleys of the high Himalayas and Antarctica. Proc. Roy Soc. B 278: 702-708. [Reprint]
Costello E.K. et al.. 2009. Fumarole-supported islands of biodiversity within a high-elevation landscape Socompa Volcano, Puna de Atacama. Appl. Environ. Microbiol. 75: 735-747 [Reprint]
Schmidt S.K. et al. 2009. Microbial activity during extreme freeze-thaw cycles in periglacial soils, 5400 m el., Cordillera Vilcanota, Perú. Extremophiles 13: 807-816. [Reprint]
Schmidt S.K. et al. 2008. The earliest stages of ecosystem succession in high-elevation (5000 meters above sea level), recently de-glaciated soils. Proc. Roy. Soc. B 275: 2793-2802. [Reprint]
Schmidt S.K. et al. 2008. Phylogeny and ecophysiology of opportunistic “snow molds” from a sub-alpine forest ecosystem. Microb. Ecol. 56: 681-687. [Reprint]
Ley R.E. et al. 2004. Microbial population dynamics in an extreme environment: Controlling factors in talus soils at 3750m in the Rocky Mountains. Biogeochemistry 68: 313-335.
Pennisi E. 2003. Neither cold nor snow stops tundra fungi. Science 301: 1307. [Reprint]
Schadt C.W. et al.. 2003. Seasonal dynamics of previously unknown fungal lineages in tundra soils. Science 301: 1359-1361. [Reprint]